Sunday, October 09, 2016
Issue #512: More Messier Madness!
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| M87 shows off its jet to my Stellacam... |
What better
time is there for chasing Ms? The nights are cooler now and their skies are
clearer (you hope). Down here, I may only have to douse myself with one gallon of Deep Woods Off instead of two.
And, oh! the Messier beauties you’ll find lurking now. The mid-late summer
objects are still on display and lookin’ good. A glance to the east, though, will show
the Autumn wonders are on the rise—look how high M15 has gotten—and
if you’re up late you’ll begin to witness glories of Winter climbing as well.
Yes, fall’s
a great time for a Messier hunt, for crossing them off your Life List. For this
week’s edition, however, we’re taking the WABAC machine back to spring as we
navigate through the countless faint fuzzies that comprise the great Coma-Virgo
cloud of galaxies.
M85
Yes, Coma –
Virgo is wonderful, but what makes it
wonderful? The sheer number of galaxies on display here and their pairings and
groupings. When you stop to think about it, many, many are ellipticals without
much detail to offer. Tons of ‘em are certainly easy enough to see with a
medium size telescope in the backyard, however, including Messier 85, a
magnitude 10.0, 7.6’ x 5.9 S0 elliptical galaxy. And you get a bonus galaxy to up the interest level;
M85 is in the field with a dimmer companion, magnitude 11.6. 3.6’ x 3.5’ NGC
4394.
To find M85?
While goto or DSCs are the way I’d go in these latter days, M85 is not too hard
to pin down. It lies about 1.5-degrees outside to the northeast of a line drawn
between two prominent stars, Diadem, Alpha Comae, and Leo’s Denebola. A
magnitude 5 range double star, 11 Comae, is just a smidge over a degree to the
west of the galaxy.
In the
backyard, you’ll want at least an 8-incher to make this object easy on the less
good nights. M85 is a galaxy that can be bright in small apertures on good
evenings, but dim to the point of toughness on poorer ones. Above all, despite
the fact that this is a lenticular with an oval, elongated shape, expect to see
nothing more than the good old “round galaxy with a brighter center.” In other
words, much like an unresolved globular star cluster. In order to see
elongation in M85, I normally require 12-inches of aperture and a halfway
decent dark(er) site.
How about
the companion, NGC 4394? While it is small, it’s not tiny and is approaching
magnitude 12. The 10-inch Dobsonian, Zelda, will show it on a nice night,
albeit sometimes with difficulty. It is about 8.0’ northeast of the main
galaxy. Medium high magnification can be a help here. In the backyard, what you
can expect to see if you can see NGC 4394 is a relatively faint, round glow.
From dark sites with larger apertures, this barred spiral galaxy begins to
reveal its arms.
M86
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| The Face lookin' atcha... |
M86, an
elliptical galaxy in nearby Virgo, as I mentioned in the last installment,
together with its companion galaxy, M84, never fails to elicit a chuckle from
me. This grouping is “The Face.” M84 and M86 form the eyes, a little elliptical
galaxy, NGC 4387, is the nose, and a near edge-on galaxy, NGC 4406, is the
mouth. At magnitude 9.8 and with a size of 10.0’ x 7.4’, M86 is quite prominent
in 8-inch and larger scopes even from a relatively compromised backyard.
As I said in
the last M-edition concerning M84, “There are so many bright galaxies within
the arms of Virgo that it’s hard to know which one you are on. Luckily, the
field here is pretty distinctive. If you simply must find 84 the old fashioned
way, it lies halfway along a line drawn between Epsilon Virginis, Vendemiatrix,
and Denebola, Beta Leonis. Positoned there, look for two bright fuzzballs about
17.0’ apart.” Which one is M86? It is the northeastern-most of the two
brightest objects in the field. It is also more elongated than M84, being a Hubble
Type E3.
As above,
the cartoonish Face is the attraction here, that and the fact that this is the western
terminus of Markarian’s chain, the mind-blowing line of galaxies stretching off
to the east. But M86 itself? Sorry, pards; it is just another bright
elliptical. Very noticeable but very featureless.
M87
And so on to
Virgo’s monstrous old fat-daddy spider of a galaxy, M87, for more of the same. This is one of those “been there”
objects: there’s not much to see; all
you can say is you’ve been there.
Actually, there’s a little more to
it than that. The knowledge that this is an awesome giant of a galaxy, a titantic
elliptical with a mass of a trillion Sols, makes its sight thought provoking and
even moving though there is no detail to be found.
The best way
to get M87 in your eyepiece is to get on the distinctive M84/M86 pair first.
Then, slew your scope a degree and a half southeast. Go slowly and examine the
field carefully, but despite the galaxy crowded nature of this part of Virgo,
M87 stands out well. In an 8-inch in the backyard it will be fairly hard to
miss, and should be duck soup for 10s and 12s.
No, there’s
not much to see of M87 other than a bright fuzzy ball. The field? Not too much
here either for a small scope from the suburbs. There are two magnitude 12
range galaxies, NGCs 4476 and 4478, about 10.0’ to the northeast, but while
they are small, they really need a 10-inch to bring them out of a bright sky
background. In my C11 from the OK but not perfect skies of the old Georgia Sky
View Star Party at Indian Springs State Park, M87 was…
Basically a diffuse
round glow like a bright, unresolved globular cluster in a 3-inch
telescope. With TeleVue Nagler Type 2
12mm, 233x I occasionally see hints of a condensed core, but it's mostly a
featureless ball.
So that’s
it? How about THE JET? M87 is possessed of a supermassive black hole at its
core, and this is the source of an incredible jet of matter spewing out of the
center of the galaxy. This jet is so huge and luminous that it can even be seen
with amateur telescopes. Alas, those amateur telescopes need to be at least in
the 20-inch range and stationed under dark skies. Ironically, my humble
Stellacam II deep sky video camera in my C8 had no problem showing the jet with
a 10-second exposure under suburban conditions.
M88
M88…M88…which
one is that? Oh, yeah, back over in Coma
Berenices. It’s a bright enough Sb with an intermediate inclination to us that
reminds me a lot of M63 (in photographs) with patchy spiral arms similar to
those of the Sunflower Galaxy. At magnitude 10.1 and with a size of 6’54” x 3’42,
it is not terribly challenging for a 4-inch when your backyard conditions are anything
better than putrid.
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| M88 |
The best way
to land on M88 is to follow Markarian’s Chain, that great river of galaxies,
from its beginning at M84 and M86 for about two degrees to the northeast to its
conclusion. Luckily for us, M88 lies right at its northeastern end and is the most
prominent galaxy in the immediate area. Take your time and move slowly; this is
indeed the Realm of the Galaxies, and in a 10-inch or 12-inch, even from the suburbs,
there are island universes all over the place. This is a rather star poor area,
but there is a 7th magnitude sun half a degree to the northwest of
the galaxy, which provides a good guide to M88.
When you are
convinced you have M88, give it a nice long look, sure, but don’t expect too
terribly much. Even larger apertures from good site only reveal that it is
strongly elongated with a brighter center. The dusty spiral arms are really for
the eye of a camera.
M89
So you want
to see M89, do you? Well, I salute you for charging through the fuzzy laden
waters of Virgo. And this is not a bad one. It’s another round elliptical like
many of the galaxies here, but is bright enough at magnitude 9.75 and small
enough at 5’06” x 4’42” that it is a reasonably easy catch for your backyard
4-inch. If you can find it. Or, more properly, figure out exactly which
fuzzball in the eyepiece is it.
Not sure
exactly what to tell you if you have to star-hop. This object is just outside
the heart of the Virgo cloud, and there are really no guide stars to help you
on your way. If you’re star-hopping with a finder, the best way to go is to
move your scope 1-degree northwest of M58, which is substantially easier to
locate.
The best way
to position the telescope on M89, though? The way I used to navigate Virgo-Coma
in the days before computers: I’d galaxy
hop. Using a 12mm Nagler eyepiece in my 12-inch telescope, I found it
remarkably easy to move around the area by hopping from galaxy to galaxy with
the widefield eyepiece and a (very) detailed computer chart. Back then, I used
Megastar. Today, you’ll probably want to use SkyTools 3’s Interactive Atlas.
When you’ve
arrived, you’ll find that while it is almost featureless, M89 is not entirely
so. According to its specs, M89 is slightly oval, but in the eyepiece it looks
entirely round. Otherwise it has a fainter halo and a brighter center. However,
on an OK night with at least an 8-inch, you may see that it has an intensely
bright, star-like nucleus, and that brings M89 into the realm of “very
attractive.”
M90
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| M90 |
In images,
M90, a magnitude 10.10, 9.5’ x 4.5’ spiral, is very pretty indeed, with a bright,
oval central region and prominent dust lanes outlining tightly wrapped spiral
arms. Unfortunately, once you get outside the central part of the galaxy, its
surface brightness is low, and the arms are mostly for imagers, though they can
be glimpsed with 10 – 12-inch telescopes on outstanding nights at outstanding sites.
Locating M90
is quite easy if you are already on M89. Just eyepiece hop, following a chain
of 10th magnitude stars north for 40’ and you are there. An 8th
magnitude star is 14.0’ southeast of the galaxy if you need more help, or just
want to be sure you are on the correct galaxy.
When you are
on M90, most of the time all you will find is the object’s strongly elongated middle
part. And it may not be quite as bright looking as you expect given the galaxy’s
fairly generous size. This is a galaxy to keep coming back to on superior
evenings, however, since under the best conditions it can begin to give up
respectable detail to medium sized instruments.
M91
Oh, how
wonderful M91 looks--in pictures. Even in fairly short exposures, this magnitude
10.9, 5.4’ x 4.6’ shows off a classically beautiful barred spiral shape with
far-flung, open arms. In the eyepiece the story, as it often is, is somewhat
different, but this is still a Messier, after all, and worthy of your attention
for sure.
If you wanna
get to M91, my advice (for the computer deprived) is to continue your eyepiece
hopping, moving 1-degree 22’ west – northwest from M90. Take it easy, since
this one definitely looks a little on the dim side. There is a magnitude 8.8
star just 17.0’ west of the galaxy.
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| Stellacam's M91... |
I hate to be
a bring-down, but even with fairly large telescopes under quite dark skies,
about all you will see of M91 is an elongated something, and you may need averted vision to see even that much. On particulalry nice evenings, you may pick up a stellar nucleus. On the other hand,
the camera loves M91, and even a 10-second exposure with my Stellacam 2 showed
its basic shape:
As befits its status as M91, this is a marvelous galaxy, big,
with a bright round core, a long bar, and easy to see, graceful arms that give
it a classic barred spiral "S" shape.
And that, as
they say, is that. Fun is fun, but done
is done.
But we are
not quite done with the Messiers here, though we are in the homestretch now, no
denying it. How about your own observing program? If you haven’t caught ‘em
all, resolve to do that over the coming year. I am hearing from quite a few of
you who intend to do that very thing, and some who even say (my blushes) they
are going to print out this series of blog entries and use them as their guide.
That’s flattering, certainly, and though I don’t doubt there may be better
guides to the M-objects than these articles, one thing is sure: the price is right!
