Sunday, June 26, 2016
Issue #499, Getting a Black Eye
But in a good way, as in gazing at the wondrous Blackeye Galaxy, M64. Yep, here is another Messier installment that features a showpiece, if one that’s maybe not quite as spectacular as last week’s M57. Actually, we’ve got not just one showpiece this morning but—count ‘em—three. There are two other goodies in this group that, while maybe not as pretty individually as M64, pack a real wallop when seen together: M65 and M66.
‘Course, to see these beauties you gotta have something to look at ‘em with. I’m not talking about your telescope. We’ve covered that ground a couple of times already. What I am talking about is something that is often claimed to be at least as important as the telescope, eyepieces.
What do I like for Messiers ocular-wise? Those who know me know I am addicted to ultra-wide apparent field eyepieces: 68-degrees, 82-degrees, 100-degrees, more. I just love the sensation of looking through a gigantic spaceship porthole. And there are practical reasons to embrace ultra-wide fields. More apparent field brings more true field with it. If you are using an un-driven Dobsonian, a larger true field means less frequent nudge-nudge-nudging to track objects.
And especially less nudge-nudge-nudging at the medium powers that are so useful in the backyard. A 12 - 14mm range eyepiece with an 82-degree apparent field gives you plenty of space, but enough magnification when used in the average telescope to spread out that yucky background sky glow and increase contrast a bit.
Unfortunately, heretofore ultra-wide fields came at a price, a price in money that was too high to allow some of us to experience 82-degrees or 100-degrees of heaven. That’s changed in the last few years with the introduction of reasonably priced imported ultra-wide angle eyepieces (actually, even top of the line oculars are imported today).
How good are these budget priced (well sorta) alternatives? The 82s have been very good for a long while. Some years ago, I tested the Uwans from William Optics and found them fully competitive with the high priced spread in almost every way. Since then, Mainland Chinese 82s have become something of a drug on the market, with very good ones from folks like Meade and Explore Scientific going for as little as 130 bucks a pop. How good are they? Very good. Usually at least as good as and sometimes better than the Uwans of yore.
What if you want MORE though? What if you want 100-freaking-degrees of AFOV? I wanted that very thing some years ago, a 100 in the 16mm focal length neighborhood. But I couldn’t afford the Cadillac, which was well over 700 dollars at the time. What my modest budget would allow was one of the first 100-degree eyepieces to come to these shores from Mainland China. These were sold wearing a variety of badges including Zhumell, Orion, and TMB. I ordered the Zhumell, not quite sure what I would get, but being pretty convinced I would not get perfection for less than a third the cost of the real deal.
And I didn’t, but you know what? The Zhumell 16mm, a.k.a., “the Happy Hand Grenade” wasn’t that bad either. Were the stars at the edge of that great big field perfect? No. There was astigmatism and other aberrations. However, much of the trouble had to do with me and my telescope and not the eyepiece.
A major reason for the ugly looking stars out toward the field edge was the astigmatism in my eyes. Another was due the coma inherent in an f/5 Newtonian mirror—no eyepiece, no matter how expensive, will fix coma; only a coma corrector can do that. All in all I was pleased. The big field was nice and since I don’t waste my time obsessing about the field edge, I thought I got my money’s worth.
Fast forward to today and things are even sweeter in the 100-degree arena. Meade (see my review of their 100-degree oculars in the August 2016 Sky & Telescope) and Explore Scientific are, again, upping the ante. Their reasonably priced 100s can, frankly, be astonishingly good. I was especially impressed by the ES 20mm. My friends and I did a shootout between it and the competition’s 100-degree 21mm a few years ago on the hallowed observing field of the Chiefland Astronomy Village and were frankly amazed. Was one better than the other? Hard, very hard, to say.
And there are new players coming onto the field with their own Chinese 100s: William Optics, SkyWatcher, and others. It’s an interesting time to be a dollar-conscious amateur astronomer with an eyepiece Jones.
So, should you pay the extra fare for the “best”? That’s for you to decide, but I’ll no longer be paying a premium for a relatively small increase in performance. All else aside, the “quality” of my vision means getting closer to perfection than what I get with less expensive eyepieces won’t help me much. Your mileage may vary, but I prefer to give up a mostly unobservable degree of improvement and use the money I “save” to pay my inevitable weekly bar tab at Heroes.
M64: The Blackeye Galaxy
Yes, the Blackeye Galaxy is spectacular, but it is a subtle spectacle. It can be detected in amazingly small backyard scopes—its magnitude of 8.52 coupled with a large but not too large size of 10’43” sees to that—but small scopes won’t show the dark patch, the black eye, near the galaxy’s nucleus that most observers long to see.
M64, located in the spring constellation Coma Berenices, is fairly easy to find without electronics, if not as easy as its predecessor on the list, M63. The best way to approach it is using magnitude 5.0 35 Comae. The star is almost halfway along a line drawn between Diadem and Gamma Comae, stars that should show up—if barely—in fairly poor suburban skies. 35 will likely require optical aid, but a 50mm finder will reveal it easily. When you have the star in the eyepiece, move 1-degree northeast and you should bump right into M64.
Your reward for hunting it down? The galaxy is undeniably impressive in a 4-inch on a nice night. In a medium power eyepiece, it’s a large oval of nebulosity that really “looks like a galaxy.” A 4-inch will also reliably show M64 is possessed of a small, near-stellar appearing nucleus. Alas, that is about it. Occasionally I’ve been convinced I’ve seen a hint of the black eye, the dust patch near the object’s center, with three and four inch backyard telescopes, but it’s just an impression I get when I use averted vision. Not something I can hold steady with direct vision.
Seeing the black eye easily takes at least an 8-inch. In the backyard, a C8 will turn it up, but it’s still not going to be something you can admire with direct vision. That will take a 10-inch on a good night at 150x and above. Wanna kick it up a notch? A larger scope under dark skies will begin to show the black eye isn’t a round black spot at all, but instead a curving arc of dark material. My C11 shows that fairly reliably at a dark but not crazy dark site. One year at the Georgia Sky View star party at Indian Springs State Park near Jackson, the C11 made this galaxy into an absolute thing of wonder.
M65: The Leo Trio (with M66 and NGC 3628)
Oh, M65 is good. Don’t kid yourself about that. M65 is slightly dimmer than M64 at an integrated magnitude of 10.25, but it is also smaller, 8.1’x2.1’, so it stands out well. That said, in the backyard on a so-so night, it’s more of a smudge that teases you with hints of detail than anything else.
M65 is easy to find manually thanks to its proximity to one of Leo’s bright “hindquarters” stars, Chertan, Theta Leonis. With Theta in the finder, scan two and a half degrees east-southeast and you should run across M65 without fail. You will also likely notice the similar (though hardly identical) M66. Which is which? M65 is the eastern galaxy and M66 is the western one.
While M65 is easy to see with a ten or eleven inch scope in the backyard—heck, it’s not really a challenge for a four or five—seeing detail is a little dicier. That takes dark skies and at least a ten-incher for me. Under suburban-country transition zone skies, there’s still not a wealth of detail to be seen in the galaxy. It’s a strongly elongated lens shaped object with a bright center. What it looks a lot like is a miniature Andromeda, M31. Under the best conditions with a 12-inch I get hints of a dust lane near the periphery of the disk, but it is not easy.
M66 at magnitude 8.92 and 9.0’ across its longest dimension appears similar in brightness to M65, but strikingly different in appearance. The most amazing thing for me is how easy it is to tell M66 from M65 visually even under rather poor conditions with a rather small telescope.
If you found M65, you can find M66, so no worries there. Once you are on the proper galaxy, what will you pull out? In the backyard, the most prominent thing is this SAB galaxy’s large, bright elongated, central region. That and a faint outlying haze is about all I get from the back 40, though. At high quality observing sites, the 10-inch or the C11 will begin to reveal at least one of M66’s huge, sweeping spiral arms and tantalizing dark details.
The true joy of M65 and M66 is in their “Leo Trio” guise, however. In addition to the two bright galaxies, there’s a third, dimmer one here, magnitude 9.48 (but looks considerably fainter than the Messiers) Hamburger Galaxy, NGC 3628. It’s a near edge-on, and when observed from dark sites with 10-inch and larger scopes it can show a prominent equatorial dust lane. If you have an eyepiece that can frame about 45’ of sky, you can get all three of these beauties in one field. Let me tell you, the view in my 10-inch Dobbie, Zelda, equipped with a 13mm 100-degree eyepiece, which easily frames all three, is stunning.
As you know, I am not the world’s greatest open cluster fan. But some I do like, like M67, Cancer’s “other” open cluster. It’s rich and it is different. It’s quite old for a galactic cluster, on the order of up to five billion years as a look at its color-magnitude diagram shows. Cool thing, though, is that this magnitude 6.9, 25.0’ cluster looks its age. M67 is a sprinkling of gently glittering amber gemstones set amidst Cancer’s lonely stars. Embers fading away at the end of time.
Finding M67 is as easy as falling off the proverbial log since the cluster lies near Cancer’s Alpha star, Acubens. While Acubens is not very bright at magnitude 4.25, it’s usually detectable naked eye from the suburbs when the Crab is riding high. When you are on it (a zero power finder working in tandem with your 50mm finder scope helps), just cruise 1-degree 45’ northwest and you will encounter this pretty group.
When you have M67, the first thing you’ll notice other than that it’s a nice, very nice, if somewhat subdued cluster, is that it is slightly elongated, and, more than that, that it is quite rich. A 10-inch under reasonably dark skies will easily show more than 100 suns here.
M68 is a very sweet little globular star cluster. Unfortunately, for some of you this Hydra object is a bit far south, declination -26. How far south is that? Well, about as far south as M83, the Southern Pinwheel. This is the last stop before you get to the land of Centaurus and Lupus, y’all. If, however, you’ve got a good view to the south you’ll like this one. It’s reasonably bright at magnitude 7.3, reasonably large at 11.0’, and loose enough to be easy to resolve without being so loose that it is dim.
The main problem for mid-northern-latitude observers hunting M68 without computers is that more than a few of them are unfamiliar with this far southern part of the sky. Best way to the glob? Probably by using Beta Corvi and Epsilon Corvi, both of which are bright. The cluster forms a near right triangle with the two and lies 3-degrees 30’ south of Beta (Kraz).
If, like me, you can get pretty far south before running into too much of the trash near the horizon, M68 can be a treat, even in a smallish scopes, as it was one night with my ETX125, Charity Hope Valentine, from the club dark site:
M68 is a pretty Shapley-Sawyer class X globular cluster in Hydra. It doesn't look as loose to me as its X rating would indicate. What I see is a somewhat elongated, very grainy appearing core. It is not close to culmination yet and is fairly low on the horizon and in the haze, but I can see quite a few tiny stars winking on and off around the edges of the central area. Best at 170x.
This globular, another of those that crowd along the base of Sagittarius’ Teapot (which believe it or not is now beginning to climb back into the sky at mid-evening), is middling good for me at magnitude 8.3 and 8’06” in size. And from more southerly latitudes than my 30-degrees it must be impressive. I doubt it would be a showpiece even if it were overhead, though. It’s a middle-of-the-road glob.
At least it is easy to find. Draw a line from Eta Sagittai through Epsilon, extend that line for another 2-degrees 30’ and you are there. Take it easy, though. If you are at a fairly high latitude, the glob might not jump out at you. Check the field carefully using a medium power ultra-wide eyepiece if possible.
With M69 in view, you are probably going to be pleasantly surprised at what you find—especially given me dissing the little guy. This Class V glob is small enough to remain bright, and not so tight as to be difficult to resolve. 150x in an 8 or 10-inch telescope from a passable site will just about always do it.
This Sagittarius glob is in many ways similar to M69. Same class, V, similar size at 8.0’, but a little dimmer at magnitude 9.06 and slightly farther south. So, the impression I get is “a lot like M69, but not quite as nice.” It’s a Messier, though, so “not so good” is still awfully good when compared to your average NGC globular.
If M69 is easy to find, M70 is Real Easy. Just draw an imaginary line between the Teapot’s base stars, Ascella and Kaus Australis. M70 is almost smack in the middle of the line. As with M69, don’t get too cavalier. If M70 is low in the sky for you, it may not be obvious in the field at first glance.
Despite its couple of minuses compared to the previous glob, the impression I get of M70 is “much the same.” It might be just a touch harder to resolve than M69 on a comparable night, but not enough to make much difference. 150x is a good power for me with the 10-inch.
So, what’s up next Sunday? We may take a week off from the Messiers. I’ve got a new piece of astronomy software here I’d like to tell you about, the new version of Deep Sky Planner, and it is my intention to do that next time. Rest assured, though, we will soon be back on the Messier trail.
Sunday, June 19, 2016
Issue #498, The Magic Ring
|The magic ring with Unk's C11 and (yes) ZWO 120MC planet cam.|
One of my Facebook friends asked me a question the other day. On the face of it, it was a simple and casual one, “Rod, do you still image the Messiers?” Sometimes the simplest questions turn out to be the most thought-provoking, however. I replied that, yes, I still take pictures of the M objects (and observe them visually as well). After sending my reply, though, there came another—internally generated—question, “Why?”
Because they are just so wonderful. Are there some objects in the NGC and other deep sky catalogs that are better, visually, than some Messiers? Yes. But the preponderance of beauty is in the Ms. Almost—if not quite—every one of them is a gem. Do I get tired of looking at them? That would be like asking whether I get tired of looking at Mona Lisa or reading Hamlet. I have never seriously observed a Messier without seeing something new in it—well maybe except for M40 and M74, but they are the only exceptions.
OK, forward we go…
We start this installment’s bunch with a bang, a real superstar. M57 has been one of my most beloved objects since I first hunted it down many a moon ago with my 4-inch Palomar Junior reflector. Not that I can say it really looked like much back then, not compared to what my telescopes of today will bring home, but, it was easy to find, it was obvious in the eyepiece, and it actually looked a little like the pictures in the astronomy books I checked out of my elementary school’s library.
Certainly M57 is a worthy target for three and four inch telescopes. At magnitude 8.8 and 3’48” across its longest axis, it is easy to see with a small telescope in the suburbs. You can see this corpse of a dead star, yes, but don’t expect too many details with a little telescope. At least you won’t have to worry much about finding it. It’s almost halfway between a line drawn between two of the little summer constellation Lyra’s most prominent stars, Beta and Gamma Lyrae.
In 4-inch and smaller instruments under less than optimum conditions—the inevitable summer haze that affects even Lyra with its nice northerly declination of +30—there is only so much you can expect. M57 will be immediately obvious, even in a fairly low power eyepiece; it’s over twice the average diameter of Jupiter and is not a planetary nebula that will masquerade as a fuzzy star. Unfortunately, all you’ll see easily is just that, that it is not a star. Its ring shape is elusive, even if you pump up the power.
At 6-inches of aperture, things get much better. It will be undeniable that M57 is a smoke ring, not just a disc. When seeing is good, it will also be easy to see that this ring is squished, that it is somewhat elongated. Finally, when you increase the power to 200x or thereabouts, you’ll observe the center is not empty, but hazy; this is a filled donut.
Frankly, the view will be much the same at 8-inches, though all of these things will begin to be easier. You’ll also note on the best nights that the “ends” of the Ring’s oval on its longest axis are not sharp, but diffuse. While, unlike some planetary nebulae, the Ring doesn’t offer strong color, you can still occasionally detect a blue-green tint in it on transparent nights, most easily with 8-inch and larger telescopes.
It’s at 10-inches that you can begin to hope for some lagniappe, including the faint star (magnitude 15 or so) that’s just outside the ring to the northwest. It’s a pretty good accomplishment to bring home that pesky sun, but it is not THE star. The Star is the Ring’s elusive central star, a white dwarf, the remnants of the sun that created the nebula.
Can you see the Ring’s progenitor with a 10-inch? Yes you can. I saw it summer before last with an humble Chinese 10-inch Dobbie. Was it easy? I wouldn’t call it easy, but it was not overly difficult either. A novice observer out there with us on the club field picked it up without much of a fuss when we told him what to look for. That’s the good. The bad is that the central star has regularly eluded me in 30-inch and 42-inch Newtonians.
|M59 and M60...|
How can the central star be easy with a 10-inch one night and impossible with a 42-inch another night? Some people think the star, which is nominally at magnitude 15 or thereabouts, is a variable. That’s possible, but I don’t really think that’s the answer. The problem is the Ring’s filled interior. If the donut hole were dark, the star would be fairly trivial. It is not; the interior is very much a light gray, and the contrast between it and a dim star is minimal.
So how do you see the central star? Really pump up the power, to 500x and higher. In the above mentioned 10, the star wasn’t there at 250x, but with higher magnification it swam right into view. To make use of high power, which spreads out the bright background in the Ring’s donut hole and increases contrast between it and the star, you will of course need good seeing. If the seeing is not good, the star will be invisible even in a very large scope. It will be smeared out of existence. Luckily, even in this day when weather patterns seem to be changing—and not for the better—I get good seeing with fair regularity in the summer and can often at least glimpse that fabled central star.
From the sublime to the ridiculous. Oh, Virgo’s M58, an SAB barred spiral galaxy, ain’t exactly ridiculous, it’s just that it’s in a whole other class compared to objects like M57. Not a bad class, mind you, it’s magnitude 9.66 and 5’54” across so it is fairly prominent for a galaxy. It’s just not liable to put your eye out.
How do you find this galaxy? Easy: push the M button on your goto telescope’s hand control followed by 5 and 8. I am not kidding. Oh, you can find it the old fashioned way with finder and chart even if you are a relative novice, but M58 is right smack in the middle of the cloud of Virgo galaxies at the heart of the constellation, between the arms of the maiden as it were. Best guide to M58? Probably magnitude 5 Rho Virginis, which is about 2-degrees to the southeast of the galaxy in this star poor area. You’ll need a detailed chart, of course, since even in suburban skies you’ll see multiple faint fuzzies in just about every field you land on here.
Once you are there, what will you see? With an 8-inch to 10-inch, you may see at least one more galaxy in the field, NGC 4564, but there is no doubt which one is M58; it is the big one. Is it also bright? I can see it from the backyard with direct vision with my 8-inch, but it is easier with averted vision. Naturally, it is more prominent in a 10. As with many galaxies, bright and dim, what it resembles an unresolved globular cluster: a bright core surrounded by fainter haze.
E5 elliptical Messier galaxy M59 is cool. Not just because it’s bright at 10.6 and shows obvious elongation n/s with dimensions of 5’24” x 3’42”, but because its field is just so beautiful. An 8-inch will turn up at least 3 galaxies here. In addition to M59, there’s M60, another bright M 25.0’ to the southeast, which is graced with a smaller companion galaxy, NGC 4647, 02’41” northwest of its center. M59 itself appears as a noticeably off-round fuzzball with a fairly extensive outer halo.
Once again, goto or digital setting circles are the way to go here. Sometimes, here in the heart of Virgo, it’s still hard to figure out which object is which, however. Luckily, the layout of these three bright galaxies is pretty distinctive, and once you orient yourself as to the way your telescope presents the field as compared to your chart—inverted, mirror reversed—it is easy to ID the fuzzies. Make it easy on yourself and use a computer charting program like Stellarium, which will allow you to flip or invert the field to match what is in the eyepiece.
Is M60 even better than M59? Perhaps. It’s got a brighter magnitude value, 9.8, but this 7’24”x6’0” E2 elliptical galaxy is not as obviously elongated. It trumps M59, however, because it has little buddy NGC 4647 beside it. An 8-inch telescope will have no difficulty picking up a faint nebulous patch beside the main object. Don’t see it? You are likely on M59 rather than M60, then. DSCs or goto are, again, the path to happiness here.
M61 is a face-on SAB spiral galaxy, and face-ons tend to be tough. Luckily, this one is fairly small and bright, 6’30” in diameter and magnitude 9.65, so seeing it is not much of a challenge. Not for a 10-inch in the suburbs. Want to do beyond just seeing it, though? A 10-inch under a dark sky can do well with this one, but a 12-inch is undeniably better.
At least it’s a little easier to find M61 than the run of the mill Virgo galaxy, it being in the western part of the constellation away from the greatest mass of objects. You’ll find M61 5-degrees north of Eta Virginis and about 1-degree 18’ northeast of a prominent 5th magnitude star, 16 Virginis. All in all, finding this one manually was a pleasantly easy surprise.
With the galaxy in the field, what you’ll see with a suburban 10-inch is a round subdued glow with perhaps a hint of a stellar-appearing core. A 12-inch makes the galaxy easier with direct vision but that is about it. Under dark skies with 10-inch and larger telescopes, you’ll see signs of spiral structure, and especially the galaxy’s most prominent, sweeping spiral arm.
Ah…summer’s coming in and that great celestial bug, Scorpius, is on the rise. Our next target, M62, a globular star cluster, looks like it ought to belong to the Scorpion, but it’s actually just over the border in Ophiuchus, in the southern part of that sprawling constellation. At magnitude 7.3 and 15.0’ across, M62 stands out well, or WOULD if it were higher in the sky for most Northern Hemisphere amateurs.
Yes, M62 belongs to Ophiuchus, but if you are finding it The Old Fashioned Way, use two of Scorpius’ stars to pin it down. The glob lies about 4-degrees northeast of the Scorpion’s body, and forms a triangle with two of his stars, Tau and Epsilon Scorpii. Assuming Scorpius is well over the horizon, and the haze and light pollution is not too bad, the M62 may show up in your finder as a wee fuzzy.
It M62 good? It would be if it were higher, but it is not. As is, in an 8-inch under the average summer conditions in the suburbs, you may have to settle for “grainy but not resolved.” A 10-inch at a dark site can bring out a satisfying number of stars in the halo of this somewhat compressed Type IV cluster.
We began on a good one and we end on a good one too, M63, the winsome Sunflower Galaxy. It is still a galaxy, however, despite the fact that it’s a Messier and has a reputation for being spectacular, so don’t expect “blindingly bright.” It is easy enough in a 4-inch, though, and can begin to show its sunflower aspect in a 10-inch under decent conditions given its bright magnitude number, 8.59, and reasonable size, 12’36”.
Finding this Canes Venatici object is easy due to its prominence and to its position about 1/3rd of the way along a line drawn between Canes’ Cor Caroli and the Big Dipper’s Alkaid. The galaxy is actually about 1-degree northeast of this line, but a little scanning with a medium-low power eyepiece should turn it up without much hair pulling.
A 4-inch telescope in the backyard will show you the basic features of this steeply inclined galaxy. It’s a prominent oval with a bright, small, but not stellar center. To see more, you will need a 10-inch and a dark site and a medium-high power ocular. With one, you can hope to glimpse the mottled, patchy, petal-like spiral arms that give rise to M63’s “Sunflower” moniker.
So..? The finish line is not yet in view; it’s a long way off yet, but I smell victory. What say we continue our M-quest next week, too?
Sunday, June 12, 2016
Issue #497, At the Messier Halfway Point
After this installment’s M-objects, we’ll be a little more than halfway through The List, or maybe considerably more than halfway through depending on exactly which objects you believe are genuine Messiers. Anyway, the star of this week’s show is, as I said last Sunday, the Whirlpool Galaxy, M51. I made a few remarks in the previous week’s article about this rather spectacular deep sky object, to include my choice of an effective telescope for viewing it, a 10-inch to 12-inch Dobsonian.
Why a Dobsonian? To begin, in this aperture, 10 – 12-inches, a Dobsonian is the most economical choice. Sure, there are a few expensive custom-made Dobs available in this aperture range, but they are far outnumbered by the inexpensive Dobbies of Synta and GSO. Is a Synta or GSO mirror the equal of a Zambuto? No, but the current imported mirrors are actually very good. It’s unusual to find one with a figure that’s not at least ¼-wave and often better, and one will serve well for deep sky observing (and may not be a slouch on the planets either). A 10-inch GSO or Synta Dobsonian can be had for around 500 dollars and is an incredible bargain.
At least as important as cost, for me anyway, is portability. A 10-inch or 12-inch fork mount SCT is a heavy telescope any way you slice it. A 12-inch Meade is frankly a beast best suited for an observatory. A 10 or 12-inch SCT OTA on a separate mount is easier to handle, if not that easy, but then you have to transport and set up a GEM (or other) mount too. I don’t mind doing that occasionally, but certainly not for an hour long Messier run from my backyard.
In contrast, a 10-inch solid tube Dob is easy and quick for most adults to transport and setup. The OTA will fit in the backseat of most vehicles, and all there is to assembling a solid tube scope is “plunk rocker box down, place tube in rocker.” This degree of portability does begin to ebb at 12-inches, admittedly. Carrying a 12-inch solid tube Dobsonian is doable for some people, but it is like wrestling with a water heater. Luckily there are alternatives.
One is the traditional truss tube scope. That is a good solution if one can be left assembled for transport to the backyard. Often that is not possible, not with the trad style truss scope. The tube assembly can be even more awkward and heavy than a solid tube telescope. And disassembling the tube to get the scope into the backyard and then reassembling it is a pain.
However, there are now 12-inch Dobsonians that are easier to handle than old-fashioned trusses and somewhat lighter than a solid tube telescope. I’m talking about the collapsible tube telescopes from Synta. Another possibility if you have considerably more bucks to spend is the ultra-light Dobsonians, which are available from several makers.
A Dob is a good choice for attacking M51 or any other Messier, but it’s one that leaves some beginners uneasy: “Don’t I need goto and tracking?” Both those things can enhance your experience, but goto/tracking is no longer the exclusive province of SCTs. Synta produces Dobsonian telescopes under its SkyWatcher brand and for sale by Orion that feature both things. And an un-driven scope can be equipped with digital setting circles that make finding easy. Isn’t it hard to track an object by hand at higher powers? Not if the telescope is properly made. I find tracking at 500x easy with my 10-inch GSO Dobbie.
None of this is to say you must have at least a 10-inch telescope to have fun with M51. A dark sky can allow much smaller scopes to do a good job on the galaxy and its companion. My experience, however, is that 10-inches is where it starts getting really good.
OK, let’s go, beginning with M50…
M50, the Heart Shaped Cluster
Do you like open clusters? You don’t? OK, OK, but this is a Messier open cluster and at least somewhat removed from the “dim, not well detached” NGC opens that provoke your scorn. M50 is bright at magnitude 5.9 and reasonably compact at 15.0’ across its longest dimension. It’s visible easily in finders and quite rewarding in medium aperture telescopes.
Since the cluster is easy in a finder, locating it is trivial on those deliciously dark and clear winter evenings after a front passage. Scan some 5-degrees northeast of Theta Canis Majoris, the big dog’s “nose” star, and you should run across M50 without a fuss. This is a fairly star-rich area, but M50 is the only open cluster of any prominence in the region.
On target, your reaction will likely be much like mine, “Not too shabby, not too shabby.” A 10-inch will show maybe 25 bright stars and perhaps three times that many fainter ones at medium magnification. This is the Heart Shaped Cluster because its looping star chains seem to outline a Valentine’s Day heart. I sometimes have trouble making out the supposed “shapes” of open clusters, but even I see a heart here. Look for the prominent red central star in the midst of M50’s suns.
M51, the Whirlpool Galaxy
And here we are at the Whirlpool. What do you need to know about it most of all? That it is beautiful, but also subtle. Its magnitude is 8.1 and its size is 11’12” x 6’54”, yielding a surface brightness of somewhere around 13, which doesn’t sound too bad, but remember you are after details, and those details, the spiral arms, the dust lanes, the “bridge” between it and its interacting companion galaxy, NGC 5195, are not easy. Sure, I’ve seen the galaxy from heavy light pollution, but only as two blobs, a bigger one and a smaller one, and most of us want the Whirlpool to be more than a “been there” object.
To do anything with M51, you have to get there, of course, and without a goto computer and in a moderately light polluted sky, that can be somewhat difficult. What works for me is a 50mm finder and a pair of 7th magnitude stars that lie 3-degrees 21’ northwest of bright Alkaid, the “end” star of the Big Dipper’s handle. M51 is just 19’ farther to the northwest and closest to the southeastern star of the pair. If you are observing from the suburbs, pay close attention to the field. M51 will not likely jump out at you.
So what will you see with a 10 – 12-inch telescope? That depends. From my club’s (semi) dark site in the suburban-rural transition zone, I can always make out spiral structure with the 10-incher, but, remember, I’ve been looking at this thing for nearly 50 years. If you are new to the Whirlpool, spend plenty of time on it, use a variety of magnifications, and employ the tricks—like averted vision--we discussed a while back. Beyond basic spiral structure? I can usually see parts of the bridge of material between the two galaxies, but it is not complete. I can also, on a good night, a superior night, see hints of the Whirlpool’s convoluted dust lanes.
|M52 and the Bubble...|
With a larger telescope, you will see more from a site like my club’s, but not a whole lot more. What this galaxy, like most galaxies, needs is a dark sky. The best view I’ve ever had of this object was with a modest instrument, my old 12-inch telescope, but that scope, Old Betsy, was sited under the very dark skies of the Texas Star Party in 1999. From there, the complete bridge was obvious (if still not blinding), and I wasn’t just able to see dust/dark lanes, I could see their edges were not smooth, but “curdled.”
M52, the Salt and Pepper Cluster
Cassiopeia’s M52, another open cluster, is not good and it’s not bad. What makes it stand out is a superb neighborhood. While a 10-inch is once again probably optimum, even a 4-inch will do a good job of capturing this magnitude 6.9, 16.0’ group.
Look for M52 about halfway along and 45’ west of a line drawn between Beta Cassiopeiae, Caph, and Iota Cephei. While not as prominent in a finder as M50, you should still be able to see something here with a 50mm.
M52’s main claim to fame—if any—is its legion of tiny stars; up to 100 are visible in medium aperture telescopes at medium-high magnifications. There’s a red central star, but the chief impression is “tiny, closely-packed stars,” which is what gives the effect of a sprinkling of salt and pepper on a dark background.
The neighborhood I mentioned? If you’ve a dark enough sky and a 10 – 12-inch telescope and maybe a nebula filter, move your telescope 36.0’ to the west and you will come upon the famous Bubble Nebula. While it is easy to image, it’s not quite so easy to see any of the nebulosity visually, much less the bubble shape, without dark skies and good transparency.
M53 has, to me, always been a herald, a herald of the return of the summer sky and its hordes of globular star clusters. This spring glob is not nearly as good as its more easterly mate, M3, but after a months of a globular shortage I welcome it, and it is pretty good. Better than puny little M79 anyway. In a dark sky and riding high, this magnitude 7.7, 13.0’ across ball of suns is pretty in a 10-inch or an 8-inch if not overwhelmingly pretty.
For once, finding is not a concern. If your site is at least good enough to show Coma Berenices’ magnitude 4.3 Alpha star, Diadem, you are in like Flynn. M53 lies a mere degree and a half to the east. On a decent night, the cluster should appear as a slightly fuzzy “star” in a 50mm finder.
When you are there, what will you see? From the average suburban backyard, all you’ll find in the eyepiece of your 6-inch and smaller scope is a fuzzball. A prominent enough fuzzball, but a fuzzball. An 8-inch will give you a cluster that wants to break into stars, but can’t quite do it. Grainy, yes, resolved, no. In 10-inch and larger telescopes, you get what you came for: plenty of tiny sparklers.
If you have really good skies and an 8-inch or larger scope at your disposal, look for M53's companion globular NGC 5053, which is loose and difficult. This open cluster-looking glob lies about a degree southeast of M53.
Here’s another glob, Sagittarius' M54. At magnitude 7.7 and a size of 12.0’, this one is hardly a spectacle. That’s largely thanks to the relatively large distance between us and this fairly compressed (Type III) star-ball. It’s some 36,000 parsecs distant and looks it.
Luckily, finding M54 is trivial if Sagittarius is decently high in your sky. It is found on the “handle” side of the Teapot’s base and is 1-degree 42’ west of Ascella, the teapot’s “leftmost” bottom star. Tread carefully, especially if your location is at a higher northern latitude. In horizon haze M54 will definitely not be prominent.
What it will be is a fuzzball. Not just in 4 – 6-inch telescopes, but in 10 – 12-inchers as well. As above, it is tight and far away, and while it begins to look grainy in 12-inch scopes, I’ve never achieved much resolution in even a 16-inch under suburban skies.
This is yet another Sagittarius globular. Alas, it’s no M22, though it might look quite a lot like that fantastic glob if it weren’t so poorly placed for Northern Hemisphere observers. As it is, this magnitude 7.42, 19.0’ group is sadly diminished.
M55 can also be difficult to find “manually.” That’s because much of the time it is in the treetops and it is also located in the rarely visited southern portion of Sagittarius well removed from the teapot. Position your telescope 8-degrees southeast of Ascella, and scan carefully with as low power an eyepiece as you can use given the probable brightness of the sky background in this part of the constellation. M55 is a loose one, a Type II, so look for something that appears to be a round and rich open cluster.
The actual appearance of M55 will depend on how high it is in your sky, the transparency in its area, and the aperture of your telescope. This is really an object for a 10-inch at least, and on a good night down here in the southland, many teeny stars are revealed in M55. It ain’t exactly a spectacle, but it’s worth your time under the right conditions.
Yes, there are Messier globular star clusters and then there are Messier globular star clusters. M56 is most assuredly not an M13. Or even an M30 or M53, though the cluster’s specs don’t sound that scary. It shines out at magnitude 8.4 from its lair in Lyra and spans a mere 8’48” of space. The problem is that it’s a Shapley Sawyer Type X. A XII is the loosest type, so M56 is much like NGC 5053, if not quite that bad—5053 is an even looser XI and is considerably dimmer.
But, yes, M56 can be tough; it was amazingly so for me when I hunted it one long ago night from my parents’ suburban backyard with my 4.25-inch Palomar Junior reflector. It was a Messier globular and Lyra was riding high. Ought to be duck soup, right? I got the scope on the cluster’s approximate position with the aid of Norton’s Star Atlas. Nothing. Nowhere. Could my aim be that far off? No. I finally spotted the little devil as a dim, very dim, round glow. That was M56?
It’s easy to get on M56’s spot without a computerized telescope as it is conveniently placed approximately halfway along a line drawn between Albireo and Lyra’s Gamma star, Sulafat. It’s actually a little bit outside that line to the east by about 45’ and slightly closer to Albireo than Sulafat. If you need further direction, a fairly prominent magnitude 6 star, SAO 68040, is 24’ northwest of the cluster.
What do you get for your efforts? From the average backyard, not much; in a 6-inch, M56 remains a smudge not much better than what I saw in the Pal Junior. An 8-inch will begin to resolve a sprinkling of stars at about 150x, but still “mostly a round glow.” Things get better in Zelda, my 10, which, when I increase the power to 200x, begins to bring home something that looks like a globular. To get more than that the solution is a dark site.
With (now sold) Old Betsy, M56 was quite attractive from darker skies like the Percy Quin State Park of the 1990s, the initial home of the Deep South Regional Star gaze. Under those good but hardly perfect conditions, the cluster began to at least approach M53. In addition to plenty of resolved stars in the outer halo, the 12-inch would show M56 has a distinct, brighter, triangle shaped core.
How did you do? What did you see? How did you see it? I’d love to hear if you’d like to post your comments. I am not able to respond to every single one, but I assure you I do read them all.
Sunday, June 05, 2016
Issue #496, A Brief Intermission…
As usual when I am on the road (which will happen more than a few times this summer), you are mostly being cheated out of your accustomed Sunday read. That may be all to the good this time, however. It gives you a chance to get out and observe the star object in my next batch of Messiers, M51. The Whirlpool Galaxy is one of the greats, and I’d like to compare notes with you.
What do you need for this spectacular but nevertheless somewhat challenging galaxy? It can look good in almost any telescope, but it cries out for a dark sky. Assuming you have that dark sky, my telescope choice is a balance of aperture versus hassle, a 10 – 12-inch Dobsonian, with the pick for (lazy) me being a 10-inch.
Anyhow, get out to your club dark site or whatever and see what you can see of its spiral structure, dust lanes, and other features and those of its companion galaxy, NGC 5195. Can you maybe even spot some of the other galaxies in the field or nearby (they are admittedly dim and small and likely a challenge for a 25-inch big gun)? You’ll find out what I was able to scope out next week, and I’m hoping you will post your observations in the comments section thereafter.