Sunday, December 18, 2016
Issue #522: Almost There, Almost There…
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| M103 |
After last
week’s slightly controversial topic, we’re back on calmer ground with the next
to the last installment of my Messier series. The end of these articles will not be the end of my
writing on the Ms, however. I have another series planned and hope to start it
in the new year. Why? After many years of ignoring Chuck’s list in my quest for
the dimmest of the dim, I find I have been drawn back to these
beautiful—well, with a couple of ringers—deep sky objects.
This week we
are heavy on galaxies. In fact, all but one of this week's crew are galaxies, the
exception being a single open cluster. That cluster is also the only one of this bunch that is readily visible now. Take heart, though; before you know
it the Lion and the Virgin will be back and with them these wonderful (and
sometimes challenging) island universes. Prepare now to take on the Virgo
challenge, touring all of the maiden’s and Coma's M-galaxies when spring comes again to the Northern Hemisphere.
M99
Messier 99,
the Pinwheel Nebula (galaxy), is, in pictures anyway, a beautiful near face-on
Sc spiral galaxy located on the western end of the great Virgo cloud. A look at its specs, magnitude 9.87 and a size of 5’44” x 4’22” don’t
make M99 sound overly difficult. That’s what I thought reading them when I was a youngun before trying to run this beast
down from my parents’ suburban backyard. I mean, my 4-inch Palomar Junior
reflector would easily show a 10th magnitude star, so why shouldn’t it
show this brighter than 10 galaxy even more easily?
Reality was a bit different as I found as soon as I began hunting the Pinwheel. There
are plenty of galaxies in this area, and I thought I'd found M99 a time or two,
but no. The star field around the galaxy is fairly distinctive, and the tools I
had at hand, Becvar’s Skalnate Pleso atlas (I knew better than to try to
navigate Virgo-Coma with Norton’s) and the wonderful “A Messier Album” column in Sky & Telescope
said “nope.” In fact, I don’t think
I saw M99 with the Pal Junior until the 1980s, though I had of course seen it with other scopes by then.
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| M99 |
The problem
for me was that while this galaxy is somewhat bright, it’s also somewhat large, and, worse, it is a face-on spiral, the most challenging species of galaxy for
backyard observers. Couple that with small aperture and primitive 1960s eyepieces (war surplus optics), and M99 was way difficult. Luckily for you, today you're likely armed with more knowledge, better finding tools, good oculars, and
larger aperture than I had way back when. It is now more than possible to find M99 from the back forty
on a good night, even without goto.
As a young
observer, it was a point of honor with me to learn to navigate the Realm of the
Galaxies. I remember that being challenging (in a good way) but also
frustrating. It still is both those things today, though we have deeper print atlases
to help, atlases like Uranometria 2000 (a good choice for Virgo) and far,
far deeper computer atlases like TheSky and SkyTools. Still, if you are more
interested in seeing that hunting, at least in this crowded area, you’ll be
much happier with go-to or digital setting circles.
If you want
to or have to do things the old-fashioned way, this is one that is not too
terribly difficult. You’ll find the Pinwheel, which is
not actually in Virgo but over the border in Coma Berenices, lurking a mere 49’
southeast of a decently bright guide star, magnitude 5.05 6 Comae. In the field of the target
object is a distinctive magnitude 7 range star, the brightest in the immediate area.
Forget the sweeping arms that give this galaxy its name. What you will
see in the backyard, even with some fairly large aperture scopes, will be a
slightly elongated lint-ball with a brighter center and, on especially good evenings,
a tiny core. From a dark site, however, a 10 - 12-inch telescope will begin to
show hints of spiral structure in the haze surrounding the galaxy’s small
nucleus.
M100
You wanna
know how hard M100 is to observe? It’s like M99, only worse (for the backyard bound).
Yes, at magnitude 9.35, it is slightly brighter than M99, but at a size of
7’24” x 6’18” it is considerably larger, which is a bad thing, especially with
face-on spirals whose light is badly spread out by their orientation to begin
with. Still, it’s on our list, so let’s go get this rascal, which is sometimes
nicknamed “the Blow Dryer Galaxy” (don’t ask me why).
The easiest
way to find M100 without electronic aid is by finding M99 first. Then, move
1-degree 44’ to the northeast and you should be on the proper field. There are
no bright stars in the area, so move slowly and carefully and use a detailed
computer charting program to help you.
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| M100 |
Actually,
there is another way to find this one or any other deep sky object: with analog
setting circles. Yes, those old fashioned “dials” can work. IF. The biggest
problem with analog circles on amateur mounts is their size, or lack thereof.
Those on many GEM mounts are too little to be anything more than useless
decoration. Those on the average SCT are better. Yes, the declination circles
are still small, but the RA circles are large enough to work well. Both also
have verniers (instructions for
using them are here).
The main requirement for using setting circles successfully is that you be well polar aligned. The
closer you are to the pole, the more accurate they will be. Oh, and you will have to
calibrate the RA circle every time you use the scope (with the drive turned
off, the RA circle, like a clock, loses “time”). Best bet is to go to a star as
close to your object as possible and set the circle to the star’s correct RA.
The declination circle on SCTs is set at the factory and shouldn’t have to be
messed with often, but if you need to calibrate in declination do just
like you did for RA.
When
everything is ready, what kind of accuracy can you expect? I used the analog
circles on my Celestron Ultima 8 SCT, Celeste, to navigate Virgo successfully
one year at the (old spring) Peach State Star Gaze. No, everything I went for
was not always in the field even at low power, but most of the
time objects were close, and I only had to do a little hunting around. At the
very least, "manual" circles will get you in the neighborhood, and a 50mm finder
will allow you to quickly refine your aim. You can also use analog circles on a
Dob, and perhaps we’ll talk about that next installment. Can analog circles be good
as digital setting circles? No, not even close, but better than just using a
finder/Telrad in bright skies? Yes.
Anyhow, when
you are on M100, what you will see from the average suburban backyard is, unfortunately, “Not much, amigo.” Under good conditions you will see
a large round fuzz spot that gets brighter toward its middle. You may also be
able to make out its star-like nucleus. That is normally all. At the dark site?
With larger apertures, some details, dust lanes and mottling, are apparent, but
don’t expect slap-you-in-the-face spiral structure. You may also glimpse a
small 14th magnitude companion galaxy, NGC 4322, 5.0’ to the
southwest.
M101
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| M101 |
You thought
M99 and M100 were tough? Hoo-boy! M101, the Catherine Wheel Galaxy, is, with M74,
the toughest of the tough in the Messiers. Why? Like the previous two, it’s a
face-on Sc spiral. But it is worse. Way worse. The reason is that it’s also
huge, 28’48” x 26’54”. Yes, M101’s visual magnitude is 7.8, but, remember, that means it is the same brightness as a magnitude 7.8 star thrown out of focus till it occupies nearly half a degree of field. Not only is its light badly spread out, it is difficult
to frame it so as to provide some contrast. You want some dark sky around this
big galaxy to furnish that contrast, but you’ll have to use a low power
eyepiece to do it. In the suburbs, the sky background is bright at low power,
so you get no contrast gain.
The good
part? Finding this galaxy’s location is easy. It forms a near equilateral
triangle with the two end stars of the Big Dipper, Alkaid and Mizar. Insert a
medium power eyepiece that gives somewhat over half a degree of true field in
your telescope—before the advent of 100-degree AFOV eyepieces, I liked 12 and
16mm 82 degree oculars depending on the scope I was using—and start staring.
I don’t want
to give you the idea that this galaxy is impossible from the suburbs; it is
not. When I was writing The Urban Astronomer’s Guide I saw it frequently with my C11 (albeit sometimes with difficulty) or, on superior nights, with the 8-inch f/5
Newtonian I was using for some of the book’s observing. It wasn’t easy, though, not
even with the C11. And I certainly could not see details:
M101 is one of the real challenges from the suburbs, and I
didn't expect much on this relatively poor night. Try as I might, I couldn't
see any hint of its outer nebulosity much less the spiral arms. After examining
the field for a while with the 12mm Nagler at 220x, I did catch sight of with
appeared to be its central area, a faint spot about 10' across, but this was
not easy in the C11.
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| M104 |
At a dark site, of course, it is a much different story. I’ve
seen the galaxy easily with 10 x 50 binoculars from the very dark Spruce Knob
Mountain in West Virginia, and reveled in its spiral arms with the C8 at f/6.3
on good evenings from less superior locations, like French Camp, Mississippi, home of the Mid South Star Gaze. On the very best nights, an LPR
filter reveals the arms are peppered with HII regions, M101’s nebulae.
M102
Take a
break, Jake. There is no M102. NGC
5866 has often been suggested as M102, but it is clear to me that 102 was
nothing more than a re-observation of 101. If you can’t bring yourself to
accept that, by all means take a gander at NGC 5866; it’s not a bad object. I’ll wait right here.
M103
Let’s take
another break, from dim and difficult galaxies at least. M103 in Cassiopeia is
a bright (magnitude 7.3) and small (6.0’) open star cluster. It’s a beauty,
though it would be even more beautiful if it weren’t set in such a rich star
field. As it is, it is sometimes slightly difficult to distinguish the actual
cluster from the background in wide-field telescopes from dark locations.
There is
nothing to finding 103. It lies 1-degree northeast of bright Ruchbah, a
magnitude 2.65 sun that is one of the stars of Cassiopeia’s “W.” When you’re on the proper spot, have a look
through your finder (scope). The cluster should be visible as a short line of
three or four brighter stars.
When you are
on Messier 103 with the main scope with a medium power eyepiece, especially a
medium power wide-field eyepiece (such oculars are surprisingly inexpensive now), you are gonna like what you see, yes indeed. My impression is that this
looks much like Cygnus’ M39, a small triangle of brighter stars with plenty of dimmer ones both within and just outside that triangle. The view is made even
prettier by the presence of a red-orange central star at the heart of the
cluster. And the whole thing is set in that crowded star field, which really
looks super from my club dark site.
M104
Gosh-a-mighty,
how I loved the Hale Reflector photographs of M104, the Sombrero Galaxy, when I
was a kid. This is one of the relatively few objects that didn’t disappoint me
too much when I first saw it with my 4-inch. Oh, the view through my 1-inch
Kellner eyepiece couldn’t compare to 200-inch plates, but, still, the basic
features were there and I was thrilled to see the renowned Sombrero with my own
eyes.
How to locate?
This magnitude 8.0, 8’42” x 3’30” near-edge-on lies in Virgo, but I always find
it easier to star hop to from Corvus. Begin at magnitude 2.90 Algorab. About
2-degrees 45’ north of the star you will notice (in the finder scope) a Y-shaped
asterism of magnitude 6.0 range stars. Trace this asterism as shown in the
picture, and you will find M104 just 25’ to the east of the last Y star.
When there,
your first impression may be, as was mine as a 12-year-old, that the Sombrero
is smaller than you thought it would be. Pump up the power to at least 150x,
though, and you will begin to see those legendary details, the “hat brim” and
the “crown,” at least. A 6-inch refractor or an 8-inch reflector will show the
famous equatorial dust lane readily on a good night. Yes, it is doable with
smaller apertures, but you’ll have to find a magnification that makes the
galaxy big enough so you can see much of anything, but which also doesn’t make
it too dim.
M105
We’ll end
this installment with another easy, pretty view. While Leo’s M105 is relatively
dim as far as its magnitude value, 9.79, goes, it is a medium sized (5’24”), almost
round elliptical with a bright center that makes it pretty easy, even in a 4-inch. Normally,
E galaxies aren’t that attractive, but this one has a couple of aces up its
sleeve, two companion galaxies, magnitude 10.0, 3’49” NGC 3384 7’19” to the
northeast, and magnitude 12.83, 2’49” NGC 3389 9’29” to the southeast. The
three together make for a superb view.
Locating M105
by manual means can be hard or easy depending on how dark your skies are and
how high the lion is in them. The best way to get to the group is to star-hop
1-degree 38’ south from Kappa Leonis. While that star is often invisible or
nearly so in the average suburban yard thanks to its magnitude of 5.45, it will
how up readily in a finder scope.
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| M105 |
After you
get done admiring Messier 105 itself, see if you can pick out the two companions
that form a triangle with the Messier galaxy. The dimmest member, NGC 3389’s, 12.83
magnitude figure sounds daunting, but I could regularly see it from the heavily
light polluted backyard of Chaos Manor South with my 12-inch Dobsonian, Old
Betsy, thanks to its small size. Not only do you get a pretty triangle of
galaxies here, M95 and M96, that pair of galaxies we visited just a
while ago, is only a degree to the southwest if you want to go on a side
trip.
One more and
we will be done with the Ms, but that won’t come for a while yet. Christmas, if
nothing else, is going to intervene. As is usual, the next blog will arrive on
Christmas Eve rather than Sunday, and will likely be shorter and perhaps more
sentimental than usual.
Nota Bene:
I’ve received word that for a variety of reasons the author of Deepsky Astronomy Software, Steve Tuma, is
discontinuing sales and support of his program. While there are other more
modern planning programs available today, DAS was one of the first and still
has some great features. Features like copious log notes for many objects from accomplished
observers—something I find often comes in handy. If I were you, I’d contact
Steve and see if you can still get a copy...
Comments:
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Hello Rod, Very nice write up as usual. Rod will or can you some write up on video astronomy using your mallincams ? maybe you all ready did. I might have missed them . thanks will w
I've done quite a few articles on the Mallincam, including one for Sky & Telescope. There are quite a few blog articles, too...just google "Uncle Rod Mallincam." Here's one I did for ATT.
http://www.waningmoonii.com/Files/Uncle%20Rod%20ATT%20-%20Jr%20PRO%20Article.pdf
http://www.waningmoonii.com/Files/Uncle%20Rod%20ATT%20-%20Jr%20PRO%20Article.pdf
The Deepsky Astronomy website is gone (http://www.deepsky2000.com). I get a godaddy ad that it's for sale. So, I guess there's no easy way to contact Mr. Tuma.
Don
Don
# posted by 
: 8:27 AM
: 8:27 AM
Steve writes: "I still have 6 sets of dvds left. If anyone wants a set just email me to my new email stuma@comcast.net and i will work something out with you."
Someday....navagation of the galaxies will be the challenge....will be the real destiny....
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# posted by : 9:27 PM
: 9:27 PM << Home
