Sunday, February 27, 2011
The Universe from Granny’s Porch
Do you ever get to feeling burned out, muchachos? Feeling that if you read one more thread on the Cloudy Nights insisting you simply must have the latest ten-thousand dollar GEM mount or you will never get anything accomplished as an amateur astronomer you will just scream? Are you sick of loading the vehicle for an hour, unloading for an hour at the dark site, and reversing the process thirty minutes later when the last sucker hole disappears?
Y’all know I love gear. I bow to no one in my lust for expensive and not-so-expensive astro junk. But there comes a time when even I reach my limit. I need a break. I need to focus on what’s Up There rather than what’s Down Here. When I get to feeling that-a-way, I first turn to my grab and go gear, a pair of humble but good Burgess 15 x 70 binoculars and a 4.5-inch Orion StarBlast reflector. I keep the binocs and the ‘Blast stationed by the door for a quick exit onto the front porch for a few minutes of uncomplicated observing.
Sometimes even the StarBlast and the binoculars seem too much. I don’t feel like hunting up a handful of eyepieces or even pulling the 15x70s from their case. But I still want to observe. And sometimes I fulfill that desire by walking out on the front porch and getting my original gear back in the game. My eyes, I mean.
Did you do any naked eye observing when you were a novice? Are you doing any now whether you are a novice or not? If the answer is “no,” you may be awful surprised at what there is to see with no more optical aid than your two peepers from the average suburban backyard.
|The Rabbit in the Moon.|
Do enough naked eye observing and the stars and constellations become not just the homes of the deep sky objects you yearn for, but friends. How wonderful it is to walk out on the front porch and see good, old Leo pulling himself up over the eastern horizon again, bringing another lovely spring with him. I suppose that’s what draws me back to the simple astronomical life. It keeps alive my relationship with the sky sans all the gimmicks and gimcracks.
My road to learning the stars began one summer night when I was camping out in the backyard with my buddies and had the epiphany that the combination of the Science Service star wheel (planisphere) I’d had for a while and the red flashlight Mama had bought me at Kress’ five-and-dime that very morning would allow me to discover the names of stars and constellations that had fascinated the little Rodster in the abstract for quite a while.
Actually, most of my learning came not from my own backyard, but from the front porch of Granny’s house downtown. I spent many a Saturday there, and usually by sundown was about played-out with whatever toys Mama had let me to bring along on our all-day-and-into-the-night visits to her mother’s.
Mama, as I’ve told y’all before, was a strong woman in many ways, but she was quite literally afraid of the dark. Daddy, a broadcast engineer, often worked the late shift at the TV station on Saturday, till “sign-off” at midnight, and Mama had a hard time enduring those (for her) scary hours alone with a little kid. Before my brother came along, Mama and me spent Saturday nights at the movies, but after he arrived it became less practical to sit through a feature, or sometimes even a double-feature, twice.
Thus came the dreaded visits to Granny’s. Actually, I loved Granny, but I was always closer to Granpa. Unfortunately, that good man was taken from us way too early. And now that we were living out in suburbia, we had a wonderful backyard and plenty of kids for me to play with including Jitter and Wayne Lee. I loved Granny, yeah, but would much rather have spent every Saturday running like a little wild Indian through the backyards and vacant lots of our subdivision.
Sure as clockwork, though, Daddy would tell Mama, “Honey, I’ll have to work till sign-off at the Studio tonight,” and I knew my Saturday plans were shot. I’d start gathering up a bag of toys, enough to occupy me through the long morning and afternoon, but not enough to incur Mama’s displeasure, “I will NOT have you dragging all your JUNK over to your Grandmother’s, YOUNG MAN.” What the traffic would bear was usually a small bag of plastic spacemen and rockets from the old Multiple Plastics toy company.
Honestly, it wasn’t so bad. Granny was the best southern cook there ever has been. Her fried chicken was to die for, exceeding even the legendary chicken to be found at Miss Monica’s restaurant in Pascagoula, Mississippi today. My Uncle Ezra, who lived at home with Granny, had a taste in movies that matched my own and there was always a horror or science fiction or jungle (Tarzan, Bomba the Jungle Boy, Jungle Jim) movie on in the early afternoon. Me and Uncle Ezra would commandeer the TV and spend an hour or two gazing in wonder at anything from Abbot and Costello Meet Frankenstein, to Attack of the 50-foot Woman, to Them.
I still remember Unk Ezra walking out onto the porch in the middle of that last movie. When I enquired, he said, “Well, Jackie Boy (what Mama’s side of the family called me), I thought I heard something, and wanted to make sure it wasn’t one of them dadgum ants.”
Other than those wonderful movies and granny’s friend chicken, what I remember most is my Saturday space voyages. Those humble plastic astronauts were imbued with a reality that’s strikingly clear to me even now. We’d start out on Granpa’s old chair, which morphed into a tiny, barren, and frigid asteroid. Maybe we’d been stranded by a recalcitrant rocket ship. Or maybe we were there to explore. Or to battle wily space pirates or crazy-strange aliens. Sometimes our explorations would take us Sunward to Venus, which was, of course, a jungle planet. It only masqueraded as Granny’s backyard.
In the golden days before Granpa was taken from us, when I was little, my adventures in space would continue till he walked out into the backyard to retrieve me with the news, “Jackie Boy, the Opry is about to come on.” I don’t know how much I really liked watching The Grand Ole Opry, but I do know I liked sitting on my Granpa’s lap while he enjoyed it. After he left us, I’d generally play till it got dark, and Granny hollered me in to supper.
After supper, I’d have preferred to sit inside and watch television, but Mama would have none of that, shooing me out onto the porch with Granny, Uncle Ezra, and whichever of our many relatives were visiting at the time. There I sat while they talked over family business, to include what was happening with the branch of the family that had set up in the far-flung hinterlands of Dallas, Texas, as related in long and excruciatingly dry (for me) letters.
What to do while the old folks sat and rocked? My brother was too young to be much company, and even when he was older it was not like we ever had much in common. I wasn’t allowed to stray far off the porch, but I could sidle down the steps and on to the walk where I could see the sky.
Granny lived more or less downtown, not far from where Chaos Manor South stands (maybe a slight bit of synchronicity). Today, you can see a little in the light pollution if you know how to do it. Actually, you can see a lot if you work at it. I’ve done the whole Messier from this area, but it ain’t easy. Back then it would have been considerably easier. The evil cobra-head mercury vapor lights were popping up by this time, the early sixties, but they were still few and far between and mostly confined to the suburbs. There were streetlights on Granny’s street, Dexter Avenue, but they were softly glowing and relatively ineffective incandescents. I could see plenty of stars.
For the longest time, I’d just gaze up at the starry sky for a few minutes and turn away, hunting for something else to distract me. That all changed after that night of backyard camping, when I made my discovery about planispheres and red lights. Suddenly the stars had begun to make sense and suddenly I was really looking at them.
After a couple of Saturdays at Granny’s, I was starting to make real headway with the season’s constellations, and my pair of .77 cent toy binoculars were now going into the brown grocery bag with the spacemen. By the time the heavens had wheeled around once, I was good. Probably I was better at and quicker at making out the constellations than I ever have been since.
Star pictures that had eluded me at first, like surprisingly subdued Hercules, were old hat and I was soon plucking out rarer game like Ophiuchus, and Serpens, and Libra. Stars? I knew a fair proportion of the named ones by heart, collecting them with all the enthusiasm of an obsessed little person. I made friends with them and they have remained my friends throughout my life, often providing immeasurable comfort. When life has been at low ebb, the sight of an old pal—Vega, Aldeberan, Rigel—shining true has always cheered me.
The stars can cheer you too, and if you are a novice you need to know them. What’s that? “But Uncle Rod, but Uncle Rod, I got me one of them newfangled go-to scopes. What for do I need to know the stars and constellations?” Above and beyond the satisfaction of knowing them, even if you have a go-to scope you still need to know the brighter stars. Yes, Celestron does have SkyAlign; that should allow you to align the scope without knowing the names of the stars you are using, but by all accounts and my own experience, their Two-Star Align is actually easier—and more accurate—and it requires you to identify one of the two stars.
Even with telescope aligned and computer cooking, you’ll want to know the constellations. Otherwise you’ll be lost in space, not knowing where to go. One glance at the western horizon and the hard-won knowledge of boyhood tells me Andromeda is going down in a hurry, and that I need to send the go-to on a go-to over there if I am to catch her wonders before it is too late.
Which planisphere should you buy? Two of my favorites, which I mentioned last week, are David Chandler’s Night Sky Planisphere and David Levy’s Guide to the Stars planisphere. Chandler’s star wheel has the advantage of having very well-drawn non-distorted constellations and is available in versions for different latitude ranges. David L’s planisphere is, most of all, large, 16-inches in diameter and easy to read. It is commonly stocked in bookstores. You could hop down to Barnes and Noble now and be learning the stars tonight.
Nota Bene: The other night I was out observing with my university astronomy students, novices all. When I began pointing out the constellations, several of them whipped out their smart phones and began tracking the sky with apps like SkySafari and Distant Suns (which use the cell phones’ built in compasses and accelerometers). These kids were able to pick out stars and constellations quicker than their classmates could with their old-fashioned Edmund Star and Planet Locator planispheres. I therefore conclude cell phones are at least on the verge of becoming the 21st century’s planispheres.
How about a book? You could get one, but you really don’t need one at first. In fact, I suggest you avoid one famous book about learning the stars, The Stars: A New Way to See Them by H.A. Rey (the author of the Curious George books). It is a wonderful book in some ways but, in my opinion, is not a big help for learning the stars. Rey was obsessed with making the constellation stick figures look like the mythological characters they are supposed to represent. His Gemini looks a lot like a set of twins, his Great Bear has a very ursine appearance, etc.
Unfortunately, Rey’s stick figures are overly complicated. It’s best to stick with the more abstract ones on your planisphere and the monthly star charts in the astronomy magazines. Those versions of the constellations don’t look much like archers or maidens (with a few exceptions), but they are easier to see and remember than Rey’s figures. Actually, you can envisage the constellation figures any way you want. The boundaries of the constellations, their areas of the sky, are set by the International Astronomical Union, but the connect-the-dots stick figures are and always have been informal.
What else will you need outside? A red flashlight, as I outlined last time, will preserve your night vision, but allow you to read the planisphere. You can get fancy red LED lights, but at first a standard flashlight with some kind of red filter over its lens will do. I always save the red cellophane that wraps the candy Miss Dorothy so sweetly gives me every February 14th to hand out to newbies to make astronomer’s flashlights, but even a layer of brown paper bag paper will be good enough at first.
Out into the yard you go. Pick an area with a clear view of at least one of the horizons. Try to find a spot that’s relatively free of ambient light, the light from nearby sources, so you can see as many stars as possible. Observing location found, set your planisphere. Rotate the wheel until today’s date lines-up with the current time—IF STANDARD TIME IS IN EFFECT. The sky doesn’t know pea turkey about daylight savings time. If you are on DST, set your planisphere for the current standard time. If, for example, your watch says “9pm,” set the planisphere to “8pm.”
One other thing: you don’t use a planisphere like a terrestrial map, looking down at it. You hold it over your head and look up at it. Hold the planisphere up with its north horizon lined up with the real northern horizon (most planispheres will have the word “north” and an arrow printed on them). Then, if you hold the planisphere steady in that position and face east, the planisphere’s eastern horizon and the real horizon will line up. Turn yourself (but not the planisphere) west, and you will see its west superimposed on the real west—and so on.
“Now hold on, Unk, what in the h-e double hockey sticks is 30-degrees in the sky?” Easy. Or easy to figure out. Mother Nature has provided us all with a built-in measuring device for angular distances in the sky, a closed fist. Hold your fist at arm’s length and the distance between the thumb side and pinky side covers 10-degrees. “But Unk, I’ve got small hands.” That’s OK…people with smaller hands generally have shorter arms and vice-versa.
Back to the sky. Don’t get flummoxed if you can’t make out the Lion at first. Two things that confusticated me as a novice were that the constellations were much larger in the sky than I’d expected them to be from my planisphere. On average, the stars seemed dimmer than I thought they’d be as well. Keep looking, going back and forth between sky and planisphere, and soon you will see.
Still having trouble making out backwards questions marks and triangles of stars much less Lions? You should note a strikingly bright blue-white star in the area. This is magnitude 1.35 Regulus, Leo’s brightest star. Once you see him, the rest is duck soup. The star is the period of the backwards question mark that is tilted to the north (left). Referring to your planisphere, trace from there, connecting the star dots till you form the Sickle/question mark. Then, move east and you will encounter the three stars that form the triangle of Leo’s hindquarters.
All-bloody-right! You have learned your first constellation and your first star. After that milestone, learning the sky is just continuing the process. Pick another prominent star figure on display at your time of year: Leo, Orion, Taurus, Pegasus, etc.—and find its pattern in the sky with the aid of your planisphere. Identify the constellation’s bright star (if it has one), and put a name to it. Spend plenty of time admiring your catches, the star and the constellation figure, till you are sure you will be able to identify them on the next evening, when they will be in nearly the same place at the same time.
When you have looked long enough to be sure you will recognize Leo (for example) in the future, move on to the constellations around him. Little Leo Minor isn’t much to look at, just three stars, but unless your skies are very light polluted, he should be easy to pick out just to the northwest of the Sickle. Coma Berenices should be rising by now. Like many spring constellations, Berenice’s Hair isn’t much to look at, just three stars. But she holds marvelous things.
Like the huge star cluster Mellotte 111, which is 5-degrees across and appears as a big splash of beautiful stars on the western side (opposite the eastern horizon) of Coma. Can’t make it out and having a hard time with Coma herself? If you’ve got a pair of binoculars, run get them. If not, think about getting some. Maybe even just a cheap pair from Walmart; they can be a real help learning in light polluted conditions. You’ll find some tips here.
Once you have the eastern horizon area down, move on to another chunk of sky. In the spring maybe the north, and check out the Bear who will be standing on her tail, the “handle” of the dipper/plough. As before, make friends with the brightest stars and fill in the nearby constellations. Take your time. Just being able to pick out a constellation once won’t help. You want to be able to identify it and at least one of its stars without a chart. To that end, test yourself. Go outside without your planisphere the next evening and try to identify the stick figures and stars without aid, checking yourself with the planisphere when you are done.
By the time four seasons have passed, if you continue this program regularly, you will have an excellent working knowledge of the sky, more than sufficient for aligning and using a go-to scope. More than that, you’ll find learning the constellations an enjoyable end in itself. As a little kid, I not only relished knowing the star patterns, but knowing their myths. It was almost as if those ancient stories represented a creed not so outworn after all. Pegasus and Perseus and Andromeda and Cassiopeia and Cepheus and the rest paraded before me and seemed just as real as real could ever be.
If you enjoy learning the stars, may I make one request? Pass it on. I am not one who thinks amateur astronomy will go to hell in a hand basket if everybody doesn’t know their constellations. Amateur radio almost died because for too many years you were not (and could not be) a ham if you didn’t know the Morse code. Thankfully, amateur astronomy is different. Anyone who loves the stars is an amateur astronomer. Still, I think knowing the stars and constellations by heart is a wonderful thing. I also think you will enjoy teaching the stars almost as much as you enjoyed learning them.
Next Time: Depends on how the weather was this past weekend, but maybe, just maybe, poor little Charity Hope Valentine is up from her sickbed.
Sunday, February 20, 2011
Getting Set II
Where were we? We’d at least got started on that steep-looking stairway to heaven that is amateur astronomy. We’d got you a telescope, probably an 8-inch Dobsonian telescope. We tried to keep our spending down to 500 big ones in order to leave sufficient money, at least a couple of C-notes, for accessories. By “accessories,” I mean vital accessories, things you cannot live without. Two-hundred will get you going there, but you must choose wisely.
Numero Uno when it comes to necessary accessories is eyepieces, oculars, or, as some newbies like to call them, “eye-lenses.” Your new telescope probably came with one or two, but that’s not enough to provide the range of magnifications needed to take on a wide variety of objects. You’ll want at least three eyepieces or at least three magnifications: low (but not too low if your sky is light-polluted) for finding and for large objects, medium power as your bread and butter eyepiece, and a high power for small objects and for the Moon and planets.
Eyepieces are simple things; all they really are is sophisticated magnifying glasses. Their purpose is to take the image formed by your telescope’s optical system and enlarge it to a size practical for detailed inspection. Long focal length eyepieces deliver lower powers and short focal length ones deliver higher powers.
What’s a good eyepiece? There are many, including wide field (68-degree AFOV range), ultra-wide field (82-degrees), and mega-wide field (100-degrees) eyepieces like Televue’s Panoptics, Naglers, and Ethoses respectively. Alas, Al Naglers’s wonders are for tomorrow. Today, they don’t just break our budget, they decimate it. Any one of these will cost more than what remains of our pot.
What exactly is AFOV, “Apparent Field of View,” anyhow? Many beginners bandy this term about without really understanding what it means. It’s purty simple, muchachos. True field of view, TFOV, is the actual expanse of sky shown by an eyepiece. If you can see the whole Moon, the eyepiece’s TFOV is at least .5 degrees. The apparent field of view of the eyepiece, the angular size of the circle you see when you look in, is different. For a Plössl eyepiece it is about 50-degrees in extent. Clear as mud, huh?
The difference between a narrow AFOV eyepiece and a wide AFOV eyepiece is somewhat analogous to the difference between watching Jersey Shore on a 50 inch big-screen TV and a 12-inch portable. You see the same thing (Snooki), but the big TV’s image is more expansive and immersive. This analogy is not quite perfect. Objects are larger on a larger TV screen, but a 12mm 100-degree AFOV eyepiece and a 12mm 50-degree AFOV eyepiece deliver the same magnification. The Moon is the same size in both; you just see more of it in the 100-degree jobber-do. Maybe a better analogy is looking at a scene through a small windowpane as opposed to a picture window.
So, no Ethoses for us. What then? There are less expensive high quality wide field eyepieces like the William Optics Uwans (a.k.a. Orion “Megaviews”), but even one of these will cost too much. Our old reliable will be Plössls.
How many eyepieces do you need? Three or four to start. Which focal lengths? That depends on your telescope’s focal length. As you may already know, the magnification produced by an eyepiece is equal to its focal length divided into the telescope’s focal length. An 8-inch f/6 scope has a focal length of 1200mm, so a 10mm eyepiece will give us 120x in this telescope (1200/10). If you followed by my advice, most of you will have purchased 1200mm focal length scopes—both an 8-inch f/6 and a 6-inch f/8 have focal lengths of 1200mm. If your telescope focal length is different, just adjust the following eyepiece focal length recommendations to give you the suggested magnifications.
So which eyepiece focal lengths do I recommend? You probably received a 25mm, which yields 48x in a 1200mm scope, a low power useful for object finding and framing larger targets. Most deep sky objects cry out for more power rather than less, though—something many beginning and not so beginning amateurs don’t realize. So, you’ll want a higher power ocular to go with the 25. A 6mm will yield 200x. That is good for planets and smaller deep sky objects. If a 6mm is not available in your eyepiece line of choice, a 7mm is just about as good.
I also strongly suggest you glom onto either a 10mm (120x) or 12mm (100x) eyepiece. This will be your workhorse eyepiece most of the time. Not only does this magnification range show off many objects to good advantage, if you live where the sky is compromised by light pollution a 12mm will spread-out the background sky glow, helping the target pop out without darkening the object beyond redemption.
How about a low power eyepiece? Sure, why not if you have the moola to spend? A 32mm or 35mm focal length eyepiece (37x and 34x, respectively) can frame larger objects nicely. Let this be the bottom-priority eyepiece, though. If, like most of us, you live where light pollution is a factor, these powers will deliver sky backgrounds bright enough to make some deep sky objects disappear.
OK, three – four eyepieces. Maybe a 32mm, a 12mm, and a 6mm in addition to the 25mm that came with new baby. Where do you get them? Plössls seem to be everywhere being sold by everybody. Which to choose? This is a good time to buy Plössls. The Chinese factories are churning them out with abandon. Even better, practically any Plössl sold by an honest-to-god astronomy vendor (i.e. not cotton picking eBay) will be just fine.
In fact, most Plössls I’ve used have been more similar in performance than different. The single exception I’ve noted is TeleVue’s Plössls. They are a cut above the rest of the pack both optically and mechanically. Alas, they cost twice as much as the competition and will bust our budget. They go for about 80 bucks a pop, and unless you are willing to up the accessory budget by another 150 or so, it’s best to compromise.
Compromise does not mean “bad eyepieces.” Orion’s Sirius Plössls, for example, are mucho cheapo at $45.95 for most focal lengths (the 32mm is $51.95), and they are not the only loss leaders. One of my low price faves, of which I have several that I use in my binoviewer, is Handsonoptics’ GTO Plössls line at $22.95 to $32.95 depending on focal length. Celestron, Meade, Skywatcher and others sell nice imported Plössls, too.
How about an eyepiece kit like those sold by Orion, Meade, Celestron and others? These kits usually include four or five eyepieces, a Barlow (see below), and some other small accessories like colored filters in a nice box. Worth it? Maybe, if one fits your budget and the eyepiece focal lengths are ones that you will really use. A 4mm eyepiece won’t get in the scope much unless your seeing is very good, for example.
One question I get frequently from the wet-behind-the-ears brigade is “Uncle Rod, do I need 2-inch eyepieces?” They sure are pretty, but my answer is, “No, not to start with.” The advantages of 2-inch eyepieces are two-fold. First, they allow wider fields. The 1.25-inch barrel restricts the amount of true field an eyepiece can deliver, no matter what its focal length. But, if, like me, you do most of your observing from light pollution, the very low powers and very wide true fields of longer than 32mm focal length eyepieces are not very useful.
What else can the 2-inch format do? Some sophisticated wide field eyepieces are only available in the 2-inch barrel size. That shouldn’t worry us now, as we are not after sophisticated wide field eyepieces, anyway.
Better? How? The narrower light cone produced by a Barlow is easier for less expensive eyepieces to handle well. The field edge of a Barlowed eyepiece may be sharper than an unbarlowed eyepiece of the same design and final magnification. Also, since longer focal length eyepieces generally deliver better eye relief—you don’t have to mash your eye up against the eyepiece to take in the whole field—a 2x Barlowed 25mm is often more comfortable to use than an unbarlowed 12mm of the same type.
How do you use a Barlow? Simple: you place the Barlow in the telescope focuser and your eyepiece goes into the Barlow. If you want to use a filter, you can thread one onto the end of the Barlow (most are threaded for this purpose) or thread one onto the eyepiece before inserting it into the Barlow.
One caveat about Barlows: if you plan to buy one, choose your eyepiece focal lengths wisely. If you buy a 2x multiplying Barlow (the usual value), there’s no point in having a 25mm, a 12mm, and a 6mm eyepiece. With the Barlow the 25mm comes close to 12mm and the 12mm becomes a 6mm. A 25mm, a 16mm, and a 6mm would be a better lineup.
Which Barlow? You are very lucky here. Almost all today’s Barlows are well made optically, even the inexpensive Chinese numbers. If they have a deficiency, it’s usually mechanical, not optical, like that the interior is not sufficiently blackened to reduce stray reflections. Me? I’ve used one of Orion’s 1.25-inch Shorty Barlows for years and years, including for planetary imaging, and have been as happy as a bird with it.
Wide Fields on the Cheap
Owl has a series of 80-degree AFOV eyepieces that, while far from perfect in fast telescopes, do fairly well at f/6 and slower. The prices are certainly right, with the most expensive one being the 20mm at $99.95, and the rest of the line being considerably less expensive. The longer focal length members of this “Ultra-black Ultra-wide-angle” series do require 2-inch focusers, but that’s OK; most if not all new 6 – 8-inch Dobs now come with 2-inch Crayford focusers now.
First off, let’s dispense with Moon filters. You don’t need them. These filters, usually green-tinted, are designed to reduce the Moon’s brightness. The Moon, however, is not really that bright. After observing Luna for a while, you will find her silv’ry glow not at all uncomfortable. And in case you are wondering, there is no chance she will damage your eyesight. Even the light of a full Moon is way too weak to hurt you. In reality, the surface of the Moon is close to the color of asphalt blacktop. Her seeming brightness is a matter of contrast and, again, is not dangerous.
“But Uncle Rod, Lunar observing is still uncomfortable for me.” If you simply must reduce Luna’s glare, do it with a color “planetary” filter or a polarizing filter. A colored filter or a polarizing filter may even enhance the details you can see. The usual “Moon filter” won’t. Also, in my experience, these green filters are often of poor optical quality. My usual solution? If the Moon is uncomfortably bright, I increase the magnification.
How about colored filters for the Solar System? Some can help. An 80a (its “Wratten” designation) blue filter can make Jupiter’s bands easier to see. A yellow filter can bring out details in Mars’ atmosphere. The improvements brought by color filters are subtle, however, and I rarely use them. You can at least move colored filters to the bottom of your Must Buy list.
Then there are the light pollution filters. No filter can make deep sky objects brighter, but LPR (light pollution reduction) filters can darken the background of the field, increasing contrast between object and sky. Light pollution filters come in three basic flavors, mild filters with wide passbands (Skyglow, Deepsky), medium with narrower passbands (UHC, Ultrablock), and “line” filters with very narrow passbands (OIII, hbeta).
Should you get one? If your budget will allow, yes. Otherwise, put a light pollution filter at the top of your "buy next" list. An LPR filter can make the difference between seeing and not seeing a nebula in light pollution, and can allow you to see more under even a good sky. Which one should you get? Stay away from mild filters. They might be somewhat useful for imaging, but don’t do enough to help visually if your light pollution is in any way serious. Stick with the UHC type medium filters. When the time comes to add another LPR, get the OIII, which works well on many objects, rather than the hbeta, which only works on a few. And by “objects,” I mean nebulae. The only deep sky objects improved by LPR filters are nebulae.
Whose to purchase? Lumicon’s filters are very good. So are Orion’s at somewhat lower prices. I particularly like Thousand Oaks filters, and have found those from Baader (often sold under the Celestron brand name) also outstanding. I did not like the single TeleVue LPR filter I owned, an OIII; it was too mild, not much like an OIII at all.
What do you get? That’s simple. Wil Tirion’s Sky Atlas 2000. It is available in various formats, but any of them are very useful for novice astronomers, and will contain more than enough stars to make objects easy to find if you are star hopping, and enough deep sky objects to keep you occupied for many years, maybe even forever.
More and more amateur astronomers have given up print star atlases for computer programs. What’s the advantage? Computer programs can show far more objects than any print atlas, even the legendary Millennium Star Atlas. They can also be customized to show as many or as few stars and deep sky objects as desired. They can be zoomed and unzoomed at will. They can even display photos of the objects you are hunting.
Cartes du Ciel and Stellarium (shown at left), that despite their freeware status will do just about anything the most expensive programs will, and will easily meet the needs of any novice. Stellarium delivers a beautiful rendition of the night sky, and is perfect for checking “what’s up.” It can also be useful for actual observing outdoors, but Cartes du Ciel is probably a better choice for use with the scope. It’s not as pretty as Stellarium, but it can go far deeper, and has features working observers will find very useful, including the ability to download object pictures from the Digitized Sky Survey.
Don’t have a laptop to use in the field? A computer program may still be a better choice than a print atlas. Most current programs can print outstanding, nearly typeset-quality charts, which will be fully customizable, making them more useful than the best book.
You need a red flashlight to protect your night vision and that of the people observing with or around you. Back in the day, amateurs used everything from a standard flashlight with a couple of layers of paper from a brown paper bag over the lens, to a real “astronomer’s flashlight” with a red lens. Today, what you want is a red LED flashlight (with a brightness adjustment; too bright a red light can ruin your night vision). LEDs, unlike filtered incandescent bulbs, produce pure red light that is especially easy on the eyes. You can even get a red light equipped with white and blue LEDs to help you find your way when you are off the field, but be sure you know which switch or switch position is red and which is white, or you will get yelled at at a star party.
Flashlight brands? I like to recommend American products, but the Rigel flashlight I bought has disappointed me, having a tendency to fall apart. I spent quite some time at a star party hunting the guts of my brand new light after it came to pieces while I had it hanging around my neck via its strap. The import red lights sold by Orion and Celestron are fine.
After a few months in the astronomy game, you’ll find you are accumulating lots of small things, and that all these things need to be contained. Especially eyepieces. They need to be protected from dust and moisture. You need an eyepiece case. Cardinal rule? Don’t get a small eyepiece case or you’ll soon be buying another eyepiece case. I have had one of Orion’s 17x12-inch aluminum cases for years and have been very pleased with it. HOWEVER…you can often find the very same thing—an aluminum case with “pluckable,” customizable foam—for about half the price at home improvement and sporting goods stores as a “tool attaché” or pistol case.
One last item. If you followed my advice and bought a Newtonian in the moderate f/8 – f/6 focal ratio range, collimation, alignment of the optics, is not overly critical. Still, you will eventually have to collimate, and for a Newtonian you’ll need a tool to help you do that. Your telescope probably came with a "collimation cap" for that, but if you have 50 bucks left over in your budget, you can do better. You can get fancy-schmantsy lasers, but a simple Cheshire-cum-sight-tube like those sold by Orion and Celestron will be almost as simple to use as a laser and will often deliver better collimation.
So, that’s it—for a little while, anyhow. Now try to forget about buying astro-stuff for a while (hard, I know), and get out there and start using it. A lot. Before buying anything else, get plenty of experience with what you have, which will ensure you know what you really need when the astronomy-buying frenzy hits again.
Next Time: The most wonderful optical instrument you own, your eyes.
Sunday, February 13, 2011
The Herschel Project Night 20: Once More Unto the Breach
I had my fingers crossed, muchachos. My toes, too. After losing the month of January due to clouds, I was anxious to get the Herschel Project going again. Having almost a thousand objects left to observe is sobering. To paraphrase Doctor Johnson, it concentrates an amateur astronomer’s mind wonderfully.
This past Saturday it did look like I might squeak by. While Saturday morning was predicted to be cloudy, unrelievedly cloudy, clearing was supposed to begin late in the afternoon. For once it looked like my timing would be right. Sunday was forecast to be dead clear, with storms not moving back into the picture till Monday. I’d be on the good side of the weather-front curve at last. The only fly in the ointment would be the temperature: 32F not long after sunset.
Which telescope? That was pretty easy. Sweet Charity, my ETX125, was out of the picture. As I told y’all last time, I fixed her broken tripod, but now she’s developed another and irritating fault. If you own a Meade scope with an Autostar hand controller, you’ve probably noticed the buttons become less responsive over time. Eventually, you have to mash them suckers with the strength of Hercules to register a key press. Last time out, Charity’s Autostar had got bad enough that it was a pain to use. So, Miss is sidelined for now. I’ve ordered a keyboard repair kit that is supposed to fix the Autostar’s problem. We’ll see, and I will let y’all know how it goes.
Maybe Charity being out of action was for the best. With the weather at least a little dicey and the temperatures low, I’d have been awful tempted to just do a few Herschel Is visually with the ETX125 and let it go at that, when what I really needed to do was get the C8 out and start knocking off aitches with the Stellacam again.
Which is what I planned. As Saturday afternoon wore on, it became obvious the sky would be clear for the evening, if a bit hazy. Blocking the Sun with my palm showed quite a lot of light scatter around Sol. No matter. The Stellacam can cut through just about anything. Into the car went Celeste, my Ultima C8 OTA; her CG5 mount; the Stellacam II; the DVD recorder; the Asus netbook PC; and all the rest of the gear I’d need to tackle the big list in a big way.
The drive out to our dark site in the northwestern part of the county is not an arduous one, and once I got past the traffic and traffic lights near the malls it was smooth sailing. I occupied the last half hour of the drive strategizing to the accompaniment of the Tijuana Brass’ What Now My Love? on the iPod.
At least I wasn’t playing the “what did I leave behind” game. As I mentioned a while ago, I’ve gone back to using a checklist, ticking off each piece of astro-stuff as it goes in the car. Freed from worry I ruminated over which Herschels to do and when.
The Herschel II would be out of the question. As y’all know if you’ve been following Unk’s somewhat Quixotic quest, what’s left there is a handful of targets in Hydra and Virgo. Given the predicted temperatures, it wasn’t likely I’d be able to last until three or four in the a.m. in order to have a shot at those stragglers. I likewise eliminated the dim fuzzies exclusive to the Big Enchilada, the complete list of 2500 H-objects. If it were as cold as I expected it to be, with, I guessed, heavy dew making it all the more unpleasant, I didn’t want to dwell on “faint, small, elliptical.” What seemed perfect was the Herschel Is.
You’ve responded so well to my detailed accounting the Herschel IIs that I’ve decided to run through the H Is as a sequel. While I’ve come across some spectacular sights in the Big Enchilada, spectacles are far more common in the original Herschel I list, and my adventures there will be far less boring for y’all to read about. While I last did the H I just a couple of years ago, the objects in it are so good that I am always ready to essay these first 400 DSOs one more time.
Arriving at the site, I noted the weather-goobers’ temperature predictions had scared off all but the hardest of the hardcore PSAS members. It would be just me and two other hardy souls. With sunset about 45-minutes away, I set to work with a will, since it takes about that long to get set up for a Stellacam run.
In addition to the scope, I had to unload and erect my observing table, a large camp table that folds in the middle and is about the size of two card tables. On that went an enclosure for the netbook computer, video recorder, and the portable (12-volt) DVD player I use as a display. This enclosure is made of plastic sign material—the same stuff politicians use for their consarned yard signs—and keeps the computer and other electronics dry and maybe a little warmer than they would otherwise be. Musn’t forget my observing chair, either. The secret to a productive observing run is being as comfortable as you can be.
Also on the table was my accessory box. I used a couple of ammo-box like “dryboxes” for the longest time, but in the interests of consolidation, I’d been looking around for a single, large replacement. I found that at my favorite “astronomy accessory” dealer, Bass Pro, in the form of a nice large Plano tacklebox with a drop-down front that reveals four drawers.
I gotta power all the electronic gear of course. These days, I don’t have to worry about the computer; the netbook will run on its internal battery for ten or eleven hours. I do need to supply juice to the DVD recorder, the DVD player, and, of course, the CG5 and the dewheaters. I use a 75ah trolling motor (deep cycle marine) battery and an inverter for the recorder and player. Celeste’s mount is fed by a 17ah “jumpstart” battery, and another jumpstarter, a 21ah job, powers the Stellacam and my DewBuster. Which I would definitely need on this night—the trunk of the Toyota was already slick with cold dew.
Next, I finished cabling everything up, including the C8’s motofocus and the NexRemote serial cable that goes from the CG5’s Auxiliary Port Expander to a USB-serial converter plugged into the netbook. There’s also a coax cable for video that runs from the camera to the DVD-corder, and, of course, power cables for scope, Stellacam, and dew heaters. Whew! I was near-about breaking a sweat despite the plummeting thermometer. All that remained was to wait for Polaris to show.
When that luminary finally put in an appearance (I verified his identity in the gloaming with my Celestron SkyScout), I centered him in the hollow polar bore of the CG5, powered-on the mount, booted the computer, and started NexRemote.
I really like the Bahtinov mask I bought for Celeste, and I will no doubt use it frequently when I finally get back to DSLR or CCD imaging. With video, however, I can set the camera for continuous two or three second exposures and focus easily without the mask on an appropriate object; an “appropriate object” being a globular star cluster. Those teeny-tiny stars are just perfect for tweaking focus. Thanks to the the motofocus extension cord I got from JMI, I can sit at the screen and focus in near real-time till those stars are as tiny as I can get them. Lepus’ M79, the only bright glob available, was my “focus aid” this evening.
Once the cluster was as sharp as I could get it, I upped the Stellacam’s exposure to the max and used M79 as a test shot to make sure camera and DVD recorder were doing their thing as they should be. I’ll tell y’all, it’s downright amazing what a deep sky video camera can do with even a lackluster globular like M79.
The camera cranking, it was time to bring up SkyTools 3 and the Herschel I list and get to work. Before I could begin, one of my buddies wandered by and enquired as to how long I thought we’d be able to hold out with the mercury now in the mid 30s. Thanks to the heavy dew, our gear and maybe us would eventually be covered with a coating of ice, and maybe sooner rather than later. I guessed “maybe ten o’clock.” Which meant there was no time to waste. Andromeda was dropping like a stone into the west, so I headed there as fast as the CG5’s slewing motors would go.
As per usual, the matter in italics was transcribed from my log audio recordings. Galaxy morphological types are given according to the de Vaucoleurs system where possible. One change this time out: the pictures here are screen grabs from my Stellacam videos. No, they ain’t as purty as the Palomar Observatory Sky Survey plates I’ve used in the past, but they still show plenty of detail, and maybe give you a better idea of what I saw on this night.
M110 (H.V.18) This satellite galaxy of M31, NGC 205, is big and bold tonight. This magnitude 8.92, 21.9’x11’ E5 peculiar looks very much like M31 itself as seen through a small scope at low power. Small star-like core, bright inner disk, diffuse oval haze. Outstanding.
NGC 7662 (H.IV.18), the Blue Snowball planetary nebula in Andromeda, is not overly impressive when it comes to detail. It’s just a round, bright snowball 32” in diameter shining at mag 8.60. The Hubble images of this show a wonderfully intricate structure, but it’s pretty bland in my C8.
NGC 7686 (H.VIII.69) in Andromeda is a large and pretty magnitude 5.6, 14’ across open cluster in Andromeda with an impressive bright star, magnitude 6.19 HR 8925, near its center. The cluster’s central region forms a figure-8 astermism, but it is really mostly shapeless.
A big but rich open cluster of magnitude 6.60, NGC 752 (H.VII.32) is impressive. The central area of this 75’ diameter group is host to several chains of stars and a small triangle of bright suns.
NGC 404 (H.II.224) is the famous galaxy “Mirach’s Ghost,” an E-S0 elliptical. It is close-on to Mirach, a mere 6’40” to the north-northwest of the star and does look a little like a ghost image of that bright sparkler. At times I fool myself into thinking I see some sort of detail in NGC 404, but tonight it is just an appropriately ghostly oval of light with a bright, small nucleus. Very easy to see at magnitude 11.2 and 3.5’ in size.
Over to Aries now for NGC 772 (H.I.112), a nice bright Sb galaxy. Large, and showing some detail, including, faintly, this off-center looking galaxy’s single, sweeping spiral arm. This SAb shines brightly at magnitude 11.09 even given its fairly large size of 7.2’x4.3’ and is very easy, showing off a bright small core in addition to its dim outer haze and arm.
To Pisces for NGC 524 (H.I.151), a bright magnitude 11.4, 3.3’ diameter face on S0-a galaxy. Naturally, there’s not much detail to be seen in this lenticular type galaxy. The field is made very nice by a couple of small galaxies, including one attractive edge-on, little NGC 516, which roosts 9’48” to the northwest.
NGC 488 (H.III.252) in Pisces is a rather spectacular face on SAb galaxy. Bright core surrounded by extensive, bright, oval haze and some hints of its tightly wrapped spiral arms. This is a magnitude 11.15, 5.2’x3.9’ gem.
NGC 637 (H.VII.49) in Cassiopeia is a small 3.0’ across magnitude 7.3 open cluster, but it is attractive and well detached from its rich field. A little clump of stars in a rich field, with a nice arc of seven bright-to-dim stars near its center.
NGC 559 (H.VII.48) is an outstanding magnitude 7.4 open cluster. Almost looks like a loose globular. Near the center of this 6’ group are two impressive arching chains of stars.
NGC 654 (H.VII.46) is another excellent small open cluster. Its central area is a round collection of brighter stars. This is set off by a scattering of many dim background suns and a brilliant magnitude 7.54 star 2’31” to the southeast of the cluster’s heart.
Magnitude 8.90 NGC 225 (H.VIII.78) is known as the “Sailboat Cluster,” but I can’t really make this nice group of bright stars into one. A medium-large 12.0’ group with two parallel star chains standing out. Maybe that’s the sailboat’s hull.
The beauty of the Herschel I is that even many of the open clusters are treasures. NGC 381 (H.VIII.64) is set in a rich field. Stands out very well as a squarish clump of bright stars. It is very obvious at magnitude 9.3 and a size of 6’.
NGC 1027 (H.VIII.66) is impressive. A little large, 20’, but fairly well detached and bright at magnitude 7.40. This open cluster sports a central region with a scattering of bright stars arranged in arcs and lines.
NGC 136 (H.VI.35) is a small galactic cluster 1.5’ in size and rather dim. I haven’t found a magnitude listed for this object in any reference, but it’s somewhere around magnitude 9 – 9.5 I would guess. It looks very much like a distant globular. A conspicuous magnitude 8.41 double star, SAO 11238, is 5’47” to the southwest.
NGC 663 (H.VI.31) is another standout open cluster at magnitude 6.4. It is large, 14’, but is immediately obvious in the star-littered Cassiopeia field. The center is wrapped with chains of stars. Staring at them, they seem to form a capital letter “A.”
A small but striking cluster 5’ in extent with a magnitude of 7.90, NGC 7790 (H.VII.56) is vaguely arrowhead-shaped. Another cluster is nearby, the similar looking NGC 7788 6’28” to the northwest.
NGC 659 (H.VIII65) is yet another great NGC open cluster. Center is marked by a rectangular pattern of bright stars and there is a very bright field star nearby, magnitude 5.78 44 Cassiopeiae 10’45” to the west. The cluster is brilliant with its small size of 5’ and magnitude 7.2. Well detached from the background.
NGC 129 (H.VIII.79) is a sprawling 19’ open cluster with its center marked by a triangular asterism of brighter stars. One of these, magnitude 8.95 DL Cass, marks the cluster’s center.
A compact open cluster, NGC 436 (H.VII.45) is only 5’ in extent. If I squint, this 9.30 knot of stars looks like a small but well-resolved globular. Central portion marked by a near equilateral triangle of brighter stars. A magnitude 7.18 star lies 14’ to the west.
Magnitude 6.5, 20’ NGC 7789 (H.VI.30) is another excellent galactic cluster in Cassiopeia. Hordes of tiny stars visible. In an oval shape. Looks a little like Omega Centauri in a small telescope at high power.
NGC 185 (H.II.707), a dwarf elliptical galaxy, a satellite of M31, is very nice. This 10.1 magnitude 11.7’x10’ dSph dwarf has an oval, elongated core surrounded by a bright oval haze set in a dimmer outer haze. A tiny, star-like nucleus is visible. Set in a rich star field.
NGC 278 (H.I.159) is a bright magnitude 11.47 face-on SABb galaxy in, of all places, Cassiopeia. One tight arm is visible in this 2.1’x2.0’ SABb spiral. Impressive.
Over to Cepheus for NGC 40 (H.IV.58), the aptly named Bowtie Nebula. The “tie” is formed by two arcs of material around the magnitude 11.6 central star. The nebula itself is 1.0’ in size and glows strongly at magnitude 10.70.
NGC 7142 (H.VII.66) is a little low, but even so it is interesting. A rich magnitude 10, 12.0’ diameter open cluster, it is composed of bright magnitude 11 – 13 stars against a background of many dimmer sparklers.
Magnitude 6.4, 5’ across NGC 7160 (H.VIII.67) is a nice enough galactic star cluster. Sparse, but small and well detached from the background. The central region is blessed with seven bright stars of magnitudes 7 - 10.
NGC 6939 (H.VI.42) is a really too low on the horizon right now. From what I can see, this magnitude 10.10, 10’ open cluster is fairly rich and is composed mostly of stars of magnitude 12 and dimmer.
NGC 7510 (H.VII.44) is another nice group. This magnitude 9.3, 6’ galactic cluster has a center composed of jumbled chains of magnitude 10 stars.
NGC 7380 (H.VIII.77) is a large and not terribly well-detached cluster. A bright, magnitude 7.6 double star is 10’37” to the west of this magnitude 8.8, 20’ open cluster. The POSS plate shows considerable nebulosity in this area, but I am not picking any of that up.
A nice intermediate inclination SAc galaxy in Eridanus, NGC 1084 (H.I.64) glows softly at magnitude 11.6 and subtends 3.26’x1.23’. Shows some spiral detail easily, particularly one far-flung arm.
NGC 1535 (H.IV.26), the Cleopatra’s Eye, a magnitude 9.4, 20” planetary nebula. Two concentric disks surround the magnitude 12.2 central star. The center is somewhat burned out with the Stellacam, but I can see what appears to be a clump of nebulosity or a “flier” in the outer ring of nebulosity.
NGC 1407 (H.I.107) is a near-round and bright magnitude 10.7, 4.6’x4.3’ E0 elliptical galaxy. It is made interesting by the presence of a slightly smaller elliptical, NGC 1400, which lies 11’40” to the west. Also in the field are two small galaxies, IC343 and NGC 1402.
NGC 2371 (H.II.316), The Gemini Nebula, PK 189-19.1, is a funny little thing. A magnitude 11.2, 1.2’ planetary nebula, it is peanut-shaped, composed of two arching lobes around a magnitude 14.8 central star that is easy to see. If I had to compare it to another object, I’d say it looks like a more subdued NGC 40.
NGC 2158 (H.VI.17), an open cluster, M35’s distant, small 5’, magnitude 12.0 companion is a marvel. Like a loose globular enwrapped in the countless stars of M35’s suburbs.
Magnitude 7, 5.0’ NGC 2129 (H.VIII.26) is a small open cluster that’s made interesting by a central assemblage of bright magnitude 7 – 9 stars that form a triangular or Christmas tree shaped asterism. Well detached from the background star field.
NGC 2420 (H.VI.1) is a beautiful and compact open cluster. A 5.0’ across and magnitude 10 ball of stars. Hordes of medium-bright magnitude 11 and dimmer stars in an oval shape.
NGC 2392 (H.IV.45), the good old Eskimo Nebula is very good tonight. Round, with the eskimo’s “ruff” and “nose” (the central star) very apparent. A magnitude 8.24 star is 1’39” to the north.
A small but rather bold group of suns, NGC 2304 (H.VI.2) is an attractive vaguely triangle-shaped cluster of magnitude 13 – 14 and dimmer stars. A 3.0’ magnitude 10.0 condensation of stars in the rich fields of Gemini.
NGC 2355 (H.VI.61) is a fairly prominent magnitude 9.7, 7.0’ diameter if somewhat pedestrian open cluster. Medium bright stars, medium rich. Oval in shape. One bright mag 7.8 star in the field 7’34” to the northeast of the cluster’s heart. Fairly well detached from the background star field.
NGC 2395 (H.VIII.11) is another average open cluster. Somewhat triangular in shape glowing at magnitude 9.40 and stretching 14.0’ across. Fairly well detached. The famous Medusa Nebula is found 34’34” to the east.
NGC 2022 (H.IV.34) in Orion is a fairly good small 28” planetary nebula shining rather weakly at magnitude 11.70. Gray and round with no obvious detail other than the magnitude 14.9 central star, which is “offset” from the planetary’s disk.
NGC 1788 (H.V.32) is a lovely and detailed reflection nebula is out in the hinterlands of Orion, about 7-degrees to the west of the belt/sword. It is a shapeless welter of bright and dark nebulosity and involved stars.
NGC 1999 (H.IV.33) is a peculiar looking little 2.0’ round patch of nebulosity with a dark lane across its face. This T shaped dark area is actually a Bok globule where, it’s likely, stars are forming. NGC 1999 is found 1-degree 19’ south-southeast of M42, and forms the tip of the “sword.”
The reasonably famous “37” open cluster 5’ across, magnitude 7 NGC 2169 (H.VIII.24), is outstanding. The 3 and the 7 are formed by magnitude 7 – 11 stars and are easy to make-out.
NGC 2194 (H.VI.5) is a spectacular magnitude 10, 9.0’ open cluster. The central region is marked by a rectangular pattern of bright magnitude 11 stars.
NGC 2186 (H.VII.25) is a typical NGC open cluster, a small clump of suns not well set off from the field. The center of this magnitude 9.2, 5.0’ cluster is nice, with a magnitude 9.89 luminary and a handful of slightly dimmer stars.
NGC 1980 (H.V.31) is the large and bright open cluster half a degree south of M42. Impressive due to its bright stars, which include magnitude 2.75 Iota Orionis. Otherwise, though, it is quite sparse.
M76, NGC 650 (H.I.193), a magnitude 10.10 2.7’ planetary nebula, is very good this evening. In addition to the two lobes and brightness variations across these lobes, the streamers of nebulosity wrapping around the main body of the nebula are fairly easy to make out.
NGC 884 (H.VI.34) (magnitude 4.40, 18.0’) and 869, (H.VI.33) (magnitude 4.3, 18.0’) have to be viewed separately due to the camera’s small field, but they are of course spectacular, even individually, and I cannot say which “half” is prettier.
NGC 1023 (H.I.156), a large SB0 galaxy in Perseus, is outstanding at magnitude 10.35 and a size of 8.7’x3.0’. It shows off a bright, elongated non-stellar core surrounded by oval nebulosity and set in a somewhat warped-looking disk.
After swinging back to NGC 2655 for a last look at the supernova, whose photons left home not long after the dinosaurs met their demise, I stopped and took stock. Fifty—count ‘em, fifty—Herschel Is were in the bag and I hadn’t had to struggle to do ‘em. The CG5 just kept banging them out; except for a few fuzzies low on the horizon, everything I requested was in the Stellacam’s field, and even those objects that weren’t were just barely “out.” The camera worked like a champ, with the cold weather reducing the thermal noise in the uncooled Stellacam to an amazingly low level, allowing me to kick up the gain a notch or two.
I wasn’t even that uncomfortable. Not at first. As y’all know, I preach the concept of “layering” for cold weather, and had progressed from sweatshirt, to jacket, to the big red coat I took with me to Bath, Maine when I wintered there one year. My fuzzy watch-cap kept my head and ears OK, and a chemical hand-warmer made my paws at least bearably warm. Nevertheless, pretty much as I’d predicted, I was now, at just after 10pm, beginning to feel seriously miserable.
I wasn’t the only one. My two mates had about had it as well and didn’t protest when I opined, “Looks like it might be time to call it.” The air was damp, very damp, and nothing is more miserable than being immersed in wet cold air. My red light revealed a coating of ice on Celeste, her mount, and every other exposed piece of gear. Enough is sometimes too much; I pulled the big switch and started the process of getting the equipment in the car, trying to focus not on my cold hands but on the warm den, big screen TV, and bottle o’ Rebel Yell that awaited me back at good, old Chaos Manor South.
The next morning the real work would begin. Transcribing the notes I’d made with my little Sony Pressman audio recorder into SkyTools 3’s logbook, checking the two DVDs I’d filled with video, and saving at least some of those sequences as stills. At least I can do all that in a warm house with a cat on my lap, muchachos. Of course, soon enough I’ll have forgotten how cold it was on this night, and when the dark of the Moon rolls back around it will be more Herschels.
Sunday, February 06, 2011
With everything you need to begin amateur astronomy in a serious way, that is. I’ve recently gotten a brace of emails from novices picking my brain as to what I would recommend as their first telescope. Should they get the 12-inch Meade SCT or maybe a 6-inch Astro-Physics refractor? And, oh, if only they had the money for a 25-inch go-to Starmaster! The punchline? Most of these folks have never—or at least only briefly—looked through a telescope of any kind, muchachos.
And I well know any of the above telescopes would be way too big and complicated for most newbies. Who would wind up overwhelmed and intimidated in a matter of weeks, if not days. Those beautiful telescopes would take up residence in a closet or go to Astromart, and one more enthusiastic novice would leave our wonderful avocation before hardly getting started.
And it is not just telescopes; the newbies are tugging at my sleeve about eyepieces, asking whether they need Ethoses to start out, or whether they can make do with Naglers for a while. Maybe they should buy two of every Ethos, in case binoviewing begins to seem like a good idea. Should they take out a home equity loan to get the oculars they are sure they must have to get started?
The enquiries from these earnest folks are often on the unintentionally humorous side—two of every Ethos indeed! I try not to laugh, and to gently steer them to the more modest. What hurts, though, are the emails from and conversations with novices of modest means, some of which darn near choke me up. Jane Newbie loves the stars so much and has dreamed of a telescope since she was a girl, but she only has, at best, five or six hundred dollars she can spend on astronomy. Shouldn’t she just forget the whole thing? Give up her dreams of voyaging the cosmos?
Thus, this Sunday’s entry, the topic of which is how you can get set up for serious amateur astronomy without spending serious moola. What we will do here this morning is completely equip you for 500 – 800 smackers, dineros, greenbacks. Which ain’t that hard. One of the most wonderful things about today’s amateur astronomy, U.S. amateur astronomy, is that we are living through a golden age of inexpensive gear.
I say “U.S.” because the price of telescopes in the UK, for example, is still on the outrageous side, though the situation there is better than it used to be. The astro-stuff we have access to on this side of the pond it is not just cheap either; much of it is amazingly good. Stuff that makes the Palomar Junior that got me going look like a buggy whip.
Isn’t it true, though, that you can get going for less than 500 dollars? A lot less? Sure is. Orion sells one of today’s better telescopes of any sort at any price, the StarBlast 4.5-inch mini-dob, for two-hundred dollars. It comes with a couple of eyepieces and even a planetarium program. You can lowball it even lower. Check out Tony Flanders’ and Josua Roth’s article on one-hundred dollar telescopes in the March 2011 issue of Sky & Telescope.
The catch with the lowest of the low-priced spread? Surprisingly, it’s not optical quality; it’s aperture. The 200 dollar and below range gets you a 4-inch or smaller telescope, which is fine at dark sites and for casual inspection of the Moon and planets, but not really enough for the deep sky if you, like most of us, live there the sky is compromised by light pollution. For that reason, I advise you to not consider a telescope with an aperture of less than 6-inches, and 8-inches is better and recommended.
How about buying used? That is certainly a viable option. 6 – 8-inch telescopes are plentiful on the used market. When amateurs move up in aperture, many of them foolishly sell the “little scope” (which would be perfect on many nights). Where do you find one? Ask around at the local club. Check out Astromart and Cloudy Nights. You can also keep an eye on your local Craigslist. If you’re brave, there is always eBay, though I don’t recommend that. Before buying used, enlist the help and advice of a fellow member of your club. If the scope is local, try to have him/her accompany you when you go to look at it.
For our purposes today, though, we’ll assume you have decided to buy a new six or eight-inch telescope (you probably don’t want to go bigger than that at first) and, very importantly, the accessories you need to accompany it. I’ve seen lots of new amateurs make the mistake of blowing their whole wad on the scope, not leaving money for things like eyepieces and star charts. The result of that is that you have a nice telescope, but it’s compromised at best and useless at worst. At the entry level for serious astronomy, you will need to set aside a minimum of 200 – 250 dollars for the “fixins.”
No matter what sort of gear you have or aspire to, amateur astronomy is and always will be a pursuit for the patient. The original title of this morning’s entry was going to be “The Herschel Project, Night 20.” Alas, ‘twas not to be. The weather reports continued to degrade as last weekend approached. But I am ever optimistic, as most of y’all know, and I did have a brief spell of hope Saturday morning when most prognosticators, including the dadgum Clear Sky Clock, were saying “pretty good till midnight.”
Thus encouraged, I decided I would indeed make tracks for the Possum Swamp Astronomical Society’s Tanner-Williams, Alabama dark site. Mama didn’t raise no fool (despite what some folks might tell you), howsomeever, so I had no intention of dragging out a ton of gear to include the C11 or even the C8 and the Stellacam and all its support equipment. No, this would be a Charity Hope Valentine night. It might be fun, if the sky cooperated, to see how many Herschel Is Charity could conquer.
If you’re a regular reader, you know Charity is my ETX 125PE. She is so named because she and the Sweet Charity of stage and screen could be sisters. Both are kinda cute, but both have a neurotic streak as well as the occasional tendency to foolish behavior and a character flaw or two besides. As I’ve often said, I sometimes expect Charity to collapse in a self-pitying heap on the observing field after I ask for just one more obscure NGC. I must admit, though, that she never has.
Saturday night, Charity was initially very well behaved. Despite not having been out of her case in months and months, her battery-backed clock was dead-on accurate. Once I got everything properly hooked up and Charity in her correct home position, she went right to two good alignment stars, landing close to them. When the alignment was done I requested M42, and Miss Valentine put the Great Nebula smack in the center of a 100x eyepiece field.
In fact, things went so smoothly that I was immediately suspicious. What was the gag? The weather gods answered that. After a quick peep at the Eskimo Nebula, I looked up from the 9mm Expanse eyepiece to see bands of clouds moving in from both west and east. In about fifteen minutes we were completely socked in. I gave it another half hour, threw up my hands, and began to disassemble my little scope.
I don’t know if Charity was miffed about not getting an adequate ration of photons, or whether it was just Charity being Charity, but she turned on me before I could get her off the observing field. With the OTA in the case, I began collapsing the tripod legs. One…two…three…NOPE. One leg resolutely refused to unlock. In fact, the lock knob seemed to be spinning freely. I was able to cram the tripod into Miss D’s Scion Xb with one uncollapsed leg, but not without saying some real bad words.
At home, I diagnosed the problem. Charity’s OTA is fairly decently made. No, it wasn’t perfect when I received it, but that was more due to slip-shod assembly than poor materials. Once I made a few repairs and mods, all was well. The tripod was and is a different story. It is about as cheaply made as a tripod can be. This is especially galling since, when I bought Charity about five years ago, Meade wasn’t exactly giving the ETX 125 away.
Frankly, the tripod has been falling apart from day one. Starting with the springs and washer arrangement a wannabe mechanical engineer “designed” to make the OTA attachment bolts easier to screw in. These springs and washers fell onto the floor the first time I assembled the scope. I threw them in the pea-picking rubbish bin where they belonged. Not long back, the small metal plates that sit inside the tripod legs under the lock bolts, and which are designed to keep the bolts from marring/bending the tripod legs when they are locked down, also fell out. There does not appear to be an easy way to replace them, but their failure doesn’t seem to have made much difference.
Now a lock knob had failed, spinning on its bolt shaft. A knob-head bolt is not an expensive item, but Meade cut to the bone here, even so. The knobs are hollow, and it was a wonder one of ‘em’s brittle plastic hadn’t cracked earlier, as it now had.
What to do? I couldn’t grip the bolt well enough with pliers to back the thing out. All I could do was use a pair of vice grips to break the knob to pieces. That wasn’t difficult—it was ready to fall apart anyway. With the bolt exposed, I was able to back it out. How to fix? I could order something from McMaster-Carr or check Home Depot, but being stingy and impatient I wondered whether there was something lying around Chaos Manor South I could use as a replacement.
As Miss Dorothy will tell you, I never throw telescope parts away. A little cogitating and I recalled I had three legs from an old Synta EQ-4 tripod sitting in the backroom. Would their lock bolts be the same diameter/threading? They were, and I replaced all the Meade bolts with the Syntas. The Synta tripod was cheap, yeah, but it and all its components were of far better quality than the pitiful Meade ETX tripod.
Because of these and the other faux pas the entire ETX tribe is heir to, I cannot recommend these cute little scopes for novices despite their outstanding optics. What do I recommend, then? Glad you asked.
Before you can decide on a specific telescope, you will have to decide on a general type of scope. At this price level, when you are buying new, the obvious choice is “Dobsonian,” a simple Newtonian reflecting telescope on an alt-azimuth mount. Yes, there are some telescopes in our price range on German equatorial, “GEM,” mounts, but most of these little GEMs are too light to be useful. The average novice will find a “point-and-shoot” Dob easier to get friendly with in the beginning, anyway.
Then there is the question of focal ratio. Many beginners get confused and hung up about this, but it is not a huge concern. Focal ratio is the focal length of the telescope divided by its aperture. The smaller the resulting number, the “faster” the scope (that terminology being a hold-over from photography). Slower telescopes, those with f-numbers of 6 and above, offer narrower fields and higher magnifications eyepiece for eyepiece than faster ones. On the good old flip side, they are less deviled by “coma,” a property of all parabolic mirrors which tends to make stars at the edge of the eyepiece field look more like comets than pinpoints. “Slower” telescopes are also less sensitive to collimation, mirror alignment, errors.
Most beginner scopes in our aperture range, six to eight inches, have f-numbers of 6 and higher and don’t display a lot of coma. The StarBlast 6-inch at f/5 is faster than most of the other beginner-friendly scopes, but at f/5 stars still look pretty good at the field edge. If you’re like me, you will find you spend most of your time looking at objects in the center of the eyepiece field, anyway, rather than agonizing about the way the stars look at the edge. Collimation, while important at f/5, is not as critical as it is when you get to f/4.5 or f/4.
You can get “introductory” Dobsonians, 8-inch Dobsonians with solid tubes (as opposed to open, skeletal “truss tubes”), equipped with computer go-to. Unfortunately, these telescopes, Orion’s Synta-made XTg series, at $850 wreck our budget, not leaving us money for even one el cheapo eyepiece. We can afford the next best thing, however; push-to, a.k.a. “digital setting circles,” with Orion’s XTi dobs. “Push to” is just what it sounds like. You, rather than motors, move the telescope toward the target, watching the read-out on a little computer box. When the computer indicates you are on target, the object of your desire should be in the eyepiece.
“But Uncle Rod, isn’t go-to or push-to a bad thing for beginners? Isn’t it better for novices to star hop? To find objects with a finder-scope and a star chart?” Come si, come sa. I star hopped for thirty-five years. Now that I have push-to and go-to, I will never go back to Sky Atlas 2000. But I am more interested in seeing objects than hunting them. You, on the other hand, may find you enjoy the hunt. Which will you like best? If you are not sure, spend some time on the local star party field with your fellow astronomy club members watching how they work and participating.
Above all, beware of embracing star hopping as a hair shirt. You do not need to forego go-to or push-to to be a real amateur astronomer. You will learn the sky anyway. You will need to know the bright stars, at least, in order to align your computer. Even if you don’t need to be able to identify all the constellations, you will find knowing them interesting and rewarding in itself. Bottom-line-time: push-to/go-to will, in the early days, ensure you see enough to keep your interest alive.
Now, down to brass tacks. There are plenty of solid tube Dobsonians out there—if not as many as there were ten years ago—but most of them come from two makers, China’s Synta (Celestron’s parent company) and Taiwan’s Guan Sheng Optical (GSO). The nature of the beast means the two makers’ telescopes are really very similar. What you want to base your choice on is price and features.
One other thing before we get started? I discovered the 6-inch Dob is becoming an endangered species. Celestron has discontinued their 6-inch Starhopper. Meade’s 6-inch solid tube (and even their 8-inch truss tube) is long gone. SkyWatcher, another Synta brand-name, sells 6es in our price range in other parts of the world, but not in the USA currently. Why should this be? I don’t know, but maybe it is not such a bad thing.
If you absolutely have to keep the numbers at the 500 dollar end instead of the 800 dollar end, consider a six. The 6-inch reflector was the basic telescope of my generation (baby-boom), and it was all many of us ever aspired to. And yet…and yet… Light pollution is worse today, and 8-inch telescopes are far more effective under those conditions. They are also insanely less expensive than they were back in Unk’s day, muchachos.
Orion (Telescope and Binocular Center)
Leaving the too-expensive XTg scopes out of the mix, Orion’s 6 - 8-inch Dobs fall into three families, The XTs, the XTis, and the StarBlasts.
Down-checks? A red dot finder is insufficient for chasing deep sky objects in light pollution. You’ll want to replace it with an 8x50mm job. Doing so will probably throw off balance despite the presence of a spring that connects the altitude bearings to the rocker box, which is designed to make balance less critical. A weight or two on the nether end of the tube can fix that, of course. The XT’s motions are smooth enough, but azimuth could be a little smoother. All-in-all a great, a wonderful, buy.
Any caveats? Not really. These scopes are even better than the XTs. A beginner, or anybody else, will want to read the manual carefully before assembling the scopes, since the Intelliscope encoders can be a bit dicey to get right. There is a Yahoogroup devoted to the Intelliscope, and the ever-solicitous Orion if you encounter problems, of course.
The problem with the StarBlast 6-inch is not its fast mirror, but its small mount. You will need to put the StarBlast on something—a table, a hefty bar stool, a specially made stand, something—to use it unless your name is “G.I. Joe” or “Barbie.”
Accessories? Both the Intelliscope and the non-computer 6-inch ‘Blasts are furnished with two Plössls, a 25 and a 10, a red dot finder and, like all Orion’s telescopes currently, a copy of the basic edition of the Starry Night software.
Me? I like the StarBlast 6, but I still prefer the full-size f/8 6-inch due to somewhat better performance on the planets at high power and the fact I can just plop the XT on the ground and use it.
Finally, if you really, really don’t want a Dobsonian and believe you can live with 6-inches of (f/5) aperture, Orion sells a Synta scope they call the “Astroview 6,” mounted on a relatively stable EQ-3/CG4 style GEM mount. This pretty telescope (barely) avoids busting our budget at $419.95.
The other major player in the Dobsonian game today is Zhumell, the somewhat odd-sounding brand name of GSO. The Zhumells are offered by a wide array of retailers, from Amazon.com and Telescopes.com (one of the multitudinous websites of the Hayneedle company) to Zhumell’s own website. Are these scopes good? Yes they are good—if you want a non-go-to, non-push-to XT-like scope. BUT there is a little catch…thus far the company and its resellers have not really glommed onto the idea of customer support, with the scopes often not even being furnished with assembly instructions.
The price is certainly reasonable for a Zhumell 8-inch (the 6-inch does not appear to be available right now). It’s a little more expensive than the Orion XT at $379.98, but in some ways it’s nicer. Some people will tell you GSO’s mirrors are better than Synta’s. I’ve never noticed that, but the Zhumell Z-8 does have some upscale features. The side bearing tension system is very well done, the scope is equipped with a 50mm straight-through finder (which I think is easier to use than a RACI), and it comes with two eyepieces, a 9mm Plössl and a 30mm two-inch eyepiece. There’s also a cooling fan for the primary, though you probably won’t need that for an 8-inch telescope unless your conditions are truly bitter. And an “improved” azimuth bearing.
The sticking point with all the Synta Dobs I’ve used is, well, their sticky azimuth motions. The Zhumell cures that by using a lazy susan bearing rather than Teflon pads. Unfortunately, in some amateurs' opinion, that makes the azimuth motion too easy. Oh, well…
Would I choose a Zhumell? If I didn’t want the Intelliscope computer and didn’t need the hand-holding and support Orion offers, I’d be mighty tempted. The telescope offers some significant improvements over the XT in my opinion.
Better still? Telescopes.com currently offers a cool Z-8 bundle. In addition to the scope and its standard accessories you get a Telrad finder-sight, a 16mm 100-degree AFOV eyepiece of Chinese origin with decent optics, a Sky-glow (a little mild for most purposes) light pollution filter, a polarizing filter, and a good beginner’s book, Terrance Dickinson’s Exploring the Night Sky. You could probably assemble better accessories on your own, but probably not for a little over 200 bucks over the price of the scope alone. This package, a little table, a red flashlight, a freeware astro-program, and you could be on your way in right smart style, muchachos. Hell, if I had a spare $599.98, I’d be tempted to take advantage of this steal.
Do you want a Dobsonian that’s a cut above the Orions and Zhumells in some ways? If you don’t mind wielding a hammer, Stargazer Steve may have you covered. Steve, who is based in Canada, will sell you one of his kits, that, when assembled, is both beautiful and functional. Yes, the tube is Sontotube—cardboard—but as a couple of generations of Dob owners have learned, that is durable and is just about perfect for a scope. The rocker boxes of Steve’s scopes are of real plywood, not particle board, putting them light years ahead of the competition.
Only downer? Last I heard, the Stargazer Steve kits are not off the shelf items. Be prepared to wait a while for your kit to make its way to you from Canada. Also be prepared to spend a little more, 379.95 for this 6-inch. What do you get? In addition to a base made from birch plywood, you get a very good Rigel Quik-finder zero power sight and a good Plössl.
While the ranks of inexpensive Dob makers have thinned in recent years, there’s still more than the above big players. There’s old-time optical company Bushnell’s six-inch Dobbie, the “Ares,” which is certainly cheap at $224.99. For which price you make out fairly well. The scope includes a couple of imported Plössls and a 30mm finder scope.
Who makes this telescope for Bushnell (who does not make any of the telescopes they sell and hasn’t in a long time)? Hard to say. It looks like a Synta, but I am not sure. Would I buy one? Not without knowing for sure who made it and trying one first. As most veteran amateurs will tell you, “Bushnell” has been synonymous with “junk” for a long time when it comes to telescopes. This Dob may be different, but I do not know that. The fact that the company's own website sports an image of this little scope pointed at the center of the Earth does not exactly inspire confidence in their astronomical expertise.
There is another frequently seen brand of Dobbie, “Galileo,” but, as is the case with the Bushnell, I know nothing much about these Dobsonians—except they seem to be a favorite of internet non-astronomy merchants, like Amazon.com and Overstock.com. What kind of a buy might they be? At over 350 bucks, their 8-inch is competing directly with Zhumell and Orion. These are attractive telescopes, but I’d need more information before trying one. Their advertisements’ information that the 25mm eyepiece shipped with the scope is of the “Astroscopic” design is enough to give this old boy pause.
Finally, there is Discovery Telescopes, who are more well known for their larger Dobs, including a line of inexpensive truss tube rigs. They do, however, still offer one Dobsonian in our range, the 8-inch PDHQ. You do get a nice plywood base, but otherwise the telescope and its accessories look pretty pedestrian to me. The kicker? This pup will set you back a cool $999 smacker-roonie-ohs.
Worth it? While it is much more expensive than the competition, Discovery scopes have often had a reputation for being better than the run-of-the-mill Chinese imports. “Often,” but not “always.” The company also has a reputation for taking a long, long time to deliver telescopes and not being very willing to communicate with the customers it keeps waiting.
Next up was supposed to be a survey of the accessories you will need. Eyepieces, charts, chairs, computer programs, yadda-yadda-yadda. But as you can see we are well and truly out of time/space for this Sunday, so that will just have to wait for a part two. Which will appear week-after-next—if the weather cooperated last night.
Next Time: Once more unto the breach, dear friends—with the Herschels.