What’s a good telescope for the Messiers? Almost any will do. You
can see all these famous objects with a freaking ETX 60mm if you have access to
dark enough skies. One good choice, however, one that will reveal plenty of
details in all the Messiers under good conditions and not cost much money is the ubiquitous Chinese 10-inch Dobsonian reflector.
Not only are these scopes inexpensive, they are relatively portable and from a
dark site they are powerful performers.
How good is my Zhumell (GSO) 10-inch Dobsonian,Zelda? Even at a dark site she is not quite as good as my old 12.5-inch
truss tube Dob, Old Betsy (sold some months ago), was. There is not a world of difference, no, but there is
a difference. Take NGC 4631, the Whale Galaxy, a popular destination this time
of year. Compared to the 12.5, the 10 shows a little less detail in the main galaxy, and the companion galaxy, “the calf,”
is a mite less prominent. Not like night and day, mind you, but I can see more
with a 12-inch.
So, all things being equal, Old Betsy was better than Zelda.
All things are rarely equal, however, and that is certainly the case here.
Betsy had to be disassembled, the truss tubes detached from the mirror box and
the upper cage assembly, for transport. Naturally, she then had to be reassembled
at the dark site. And then taken apart when the run was over. Also, while Bets did a
fairly good job of holding her collimation following disassembly and
reassembly, she would always need to be tweaked.
Finally, as y’all know, I am one lazy mutha these days, and even with
all the weight-saving measures my friend Pat applied to Betsy during her last
baseline upgrade, her mirror box was still on the heavy side. For me.
Zelda? She’s a solid (steel) tubed scope, so the only
disassembly that needs to or can be done is removing tube from rocker. Said
tube easily fits into the backseat of my Toyota 4Runner, Ms. Lucille Van Pelt, and the
Rocker box goes in the cargo area upright. While the tube is not light, it’s
not a problem for even your broken down old Uncle, and all I have to do to get
the scope ready to go is place tube in rocker. Oh, and check collimation. While
I check it every time, however, it rarely needs even minor tweaking thanks to
her solid tube nature. Yes, you could get a solid tube 12.5-inch, but don’t do
that unless you fancy wrestling with a water heater, Padawans.
Those are not the only good things about Zelda. While Betsy
had a very decent (JMI) Crayford focuser, Zelda’s GSO focuser is better; it’s a
two-speed and is smooth and easily handles my heaviest two-inch eyepieces. In a
way, it’s not a fair comparison, since I bought the JMI back in 1998, and
we’ve come a long way price/performance-wise with focusers, but still…
There’s also Zelda’s fan. She came from GSO with a cooling
fan installed on the rear cell. At first I wasn’t sure that was needed, but as
below I now believe it can be a help, a big help, in achieving superior images
even in my mild climate where indoor and outdoor temperature variations even in
winter and early spring are rarely extreme.
So, last Saturday night, which promised to be clear, at
least for a while, I was impelled to pack Zelda in the truck and head for our
club dark site half an hour to the west of the New Manse, out in the Suburban-Country
Transition Zone. While, it did not appear conditions would hold, I thought I’d
at least be able to scope out a few Ms, if not any of the subjects for this
week, and worse come to worst maybe put in some time with Jupiter, who was now
riding high.
Setting up Zelda and checking her collimation (still spot
on) was the work of maybe 5-minutes and then it was M-time big-time. First was
the bright galaxy pair in Ursa Major, M81 and M82. While the poor seeing and
haze didn’t make M81’s arms exactly pop out, it still looked good, as did its companion, M82. Biggest surprise? Even in somewhat punk conditions the less well known third member of the group, magnitude 10.6 NGC 3077 was wonderfully prominent.
Next was good, old M51, the Whirlpool galaxy and its little
buddy NGC 5195. This was a test of my somewhat atrophied finding skills, I
suppose. Especially since I’d left my tablet, which runs SkySafari 4, at home
(by mistake, natch). All I had on me was the smaller sized edition of Sky & Telescope’s Pocket Sky Atlas,
which is a little tough for my eyes.
Nevertheless, with the aid of Zelda’s zero-power Rigel Quick
Finder and her (included) 50mm right-angle-correct-image finder, I soon found I
had nothing to dread. With SkySafari it would have been even easier to get the
Whirlpool in the eyepiece, but I must admit that for visual it’s nice to forget
about computers and batteries sometimes, even my Asus tablet, a very modest and
user friendly computer.
Onward! I guess, like riding a bicycle or copying the Morse
code, you never really forget how to star-hop. It took about 15-seconds for me
to get on M65, M66, and NGC 6628, the famous Leo Trio. I easily beat a VX mount set up near me to the target. Unfortunately, it was still a bit early and the group was
still in the Mobile light dome to some extent. Nevertheless, Zelda easily
showed the different shapes of M65 and M66 and revealed the third galaxy (barely).
If I beat the go-to rig to M65/66, I really smoked it on M3. Use the Quick Finder to
position the scope in approximately the correct area of Coma, take a look in
the finder, which showed the cluster as a fuzz-spot, center that spot in the crosshairs, and I was done. One of the benefits of a 50mm finder is that it
will show any decently large Messier from any decently dark site. The cluster? It was down in the light dome, but the power of 10-inches of telescope mirror was apparent; M3 was
beautifully resolved in the 13mm Ethos eyepiece.
I looked many objects following M3, but as the night began to grow old the haze
began to devolve into real clouds, almost bringing on Big Switch Time. Jupiter
was in a sucker hole, though, so I spent some time with him. How did he look?
OK, but just OK. The seeing was only enough, just barely good enough, to tantalize with fine
details coming and going on the giant planet's disk.
As above, I found the scope’s fan helped. Given the night’s
steadily falling temperatures, the fan ensured my higher power images were as
good as they could be in the messy seeing. Instead of just running the fan for
half an hour before beginning the run, I had it on all night and I believe that
is the way to go when the temperature is changing much. The fan, mounted on the
mirror cell, will go almost forever on its eight AA cell battery pack and
doesn’t introduce any obvious vibration, so there is really no reason not to
let it run.
So much for the preliminaries; now for the good stuff. Let’s
have a look at this installment’s deep sky treats.
M28
Well, I don’t know if I’d exactly define Messier 28, Sagittarius' little globular star cluster, as a treat, but it is an M, and it is an at
least interesting object, if not spectacular. M28's basic problem? Not that it’s
too small and too faint, not with a size of 13.8’ and a magnitude of 6.9. It’s its
declination, almost -25 degrees. That puts it down in the horizon trash for many of us
much of the time. The fact it’s fairly compact, a Shapley-Sawyer Type VII,
also doesn’t help when you’re trying to resolve it. It’s not that bad for me
down here at 30N, but it is certainly no competition for nearby M22.
One thing you will not have to worry about is locating M28
if you don’t have computerized pointing. M28 is a mere degree northwest of
bright Lambda Sagitarii, the teapot’s "lid" star. Once you have the glob in your
field, what do you get for your troubles however minimal? This is what I got
with Big Bertha, my NexStar C11 one fair but not great night at the club site:
Interesting little globular that
benefits from higher magnification in the C11. At 200x it wants to resolve. But is still basically a gray, round ball with a
few stars winking in and out with averted
vision.
M29
Messier 29 is a sparse open cluster in Cygnus, a little group
shining with a collective magnitude of 7.5 and covering 10.0’ of sky. Under
suburban conditions, a 4-inch telescope will reveal maybe 20 stars on a superior
night. A larger instrument will show more, but not many more. And yet, and yet… I’ve always liked this cute little sucka.
Maybe because its stars are arranged in a distinctive dipper-like pattern, like
a miniature M45:
M 29 is immediately identifiable in
a 22mm Panoptic eyepiece in the C11.
Basically a small dipper asterism with 8 prominent members and perhaps
twice that many dimmer ones that might be members of the group. Going to 220x
pulls out more a few more stars. Fills about half the field of a 12mm Nagler.
This cluster is attractive and stands out well tonight at high power, but it's
best at the lower magnifications.
M30
Good one alert! Good one Alert! M30 doesn’t get tremendously
high in the sky in the Northern Hemisphere. It’s situated in Capricornus at a
declination of -23, but its magnitude of 6.9 coupled with a modest size of
12.0’ means it remains prominent.
I’ve always called this one “the Goat Cluster,” and not because of its location in the Sea
Goat. On any passable night with a 6-inch or larger scope, you can see two
streams of stars coming off the core that—amazingly—resemble the horns of a
goat. While the cluster doesn’t offer tremendous resolution for an 8 - 10-inch
telescope, plenty of stars are still resolved. One of my very favorite fall objects.
M31
Good God, what can you say about Andromeda's awesome galaxy? It is
high in the sky for most Northern Hemisphere observers and is shining at magnitude 4.3.
Unfortunately, it extends a huge 2.6-degrees. That doesn’t harm its
brightness; I could often see it naked eye on a clear, dry night from old Chaos
Manor South in Mobile’s Garden Historic District downtown. It’s not
brightness or lack thereof, but that enormous size that makes “Andromeda” less
than impressive in larger telescopes.
What you’ll see in your 8-inch, even at low power, is a
bright ball, the central condensation of the galaxy enwrapped in bright haze.
Slewing around shows lots more haze, but it admittedly it doesn’t look much
like a galaxy. To make it do that, you need wide, wide field. My 80mm APO or, better, my 25x100 binoculars are my favorite M31 instruments.
Not that larger telescopes don’t have their place with M31
when you want to zoom in on details—and there are plenty of details to be seen
here. Everything from a tiny, star-like nucleus, to a massive star cloud with
its own NGC number, NGC 206, to a huge system of globular clusters, the
brightest of which are visible in an 8-inch scope as slightly fuzzy
“stars.”
M32
M32 is the brightest of M31’s satellite galaxies. It is
analogous to our own Large Magellanic Cloud, and is impossible to miss 24’13”
south of M31’s center. It’s bright and it’s slightly oval, but beyond that,
details are hard to come by. It’s an elliptical galaxy, so technically there
really shouldn’t be much detail to see here. On the best nights at high magnifications
with apertures of 10 – 12-inches, I occasionally think I do seem to be able to make
out some sort of very subdued dark features in its halo. This is, however, more
than likely averted imagination.
M33
From the suburban backyard, beautiful and graceful M33, The
Triangulum Galaxy, can be tough, with only a small round central condensation
being visible. That’s not surprising since the galaxy, while relatively bright,
extends a whopping 61.7’ x 31.3’. I can almost always find it even from yucky
skies, however, if I am careful in positioning the scope 4 degrees 15.0’
northwest of Alpha Triangulii, the apex of the triangle.
From darker skies, M33 is an entirely different story. Not
only does a 10 – 12-inch easily pick out its loose spiral structure, several
HII regions, most notably NGC 604, a huge analog of our own Orion Nebula,
become visible. This is one time you might want to use a UHC filter on a galaxy.
It will dim M33, but make its nebulae pop right out. Further enhancing the view
(without the filter) are numerous dim stars sprinkled across the galaxy’s face.
M34
"Ho-hum, it’s a ho-hummer." I’ve never been a big fan of M34.
It’s just too large at 34.0’ to be very striking in an 8 or 10-inch telescope. It’s also set in a rich field and the cluster stars don’t jump
out at you as much as you’d think they would even in a wide field instrument.
And yet, I must admit that with a 35mm Panoptic eyepiece in Zelda, M34 can be
striking, showing maybe 40 bright stars, many of them arranged in curving arcs.
“Striking,” yeah, but not “blows you away.”
M35
We’ll end on a high note. Gemini's M35 is one of my superstar open
clusters. Not necessarily because it is the most beautiful of the Messier
galactic clusters—it’s very rich but a little large at 25.0’ across when compared to nearby
M37. It’s that there’s a bonus object here, little NGC 2158, a much dimmer and more distant magnitude 12.2, 5.1’ group located less than half a degree southwest of M35’s center.
With a wide field, you get a tremendous sense of depth when viewing the closer M35 and the more distant NGC 2158. A 10
– 12-inch is able to resolve many faint stars in 2158 at higher power. I
could even see a few from Chaos Manor South with Old Betsy.
Next time? Next time Messier wise will be in part the marvelous
Auriga Trio, M36, M37, and M38. Before I do that, though, I am still planning
on bringing you the latest installment in my (some would say scandalous)
ongoing love affair with refracting telescopes.
Thanks Ron. It's Good info.
ReplyDeleteMy nearly 20 year old 12 inch F5 Hardin Optical scope is gracefully aging. Being retired I may not be able to upgrade. I've looked on smaller scopes like a plague. So it's good to know the difference in performance isn't that much.
I installed a 4.5 inch computer fan on the back of my scope from the dinky 3 inch that came with it. On some nights my viewing is better without it because the fan creates a small amount of turbulence on it's own!
Thank you. :-)
Mike Boyle
You wrote "Biggest surprise? Even in somewhat punk conditions the less well known third member of the group, magnitude 10.6 NGC 3034 was wonderfully prominent." Do you mean NGC 3077?
ReplyDeleteLove your M series. I am copying it to my iPad to have handy. Thanks.
Don Horne
Rod,
ReplyDeleteThanks for another relaxing Sunday afternoon read. I agree that there's a lot to be said for a solid tube Dob. I have a 12.5 Teeter, a VERY nice scope, but I mainly take it to star parties where I'm camped for at least two nights, preferably more. Most of the time I use my little 7" Dob for one nighters. Also I finally took delivery of a back ordered SW 100 ProED, which is for grab-and-go. I'm very impressed with the views so far, no in-focus chroma that I can see, and the images are as sharp as any I've seen in a 4".
Thanks again for a trip through the M's.
John O'Hara
Oil City, PA
Yep, I REALLY meant 3077. Thanks. :-)
ReplyDeleteI see Zelda is sporting a Genuine Gabe D. finder cover. Functional, yet unpretentious. :-)
ReplyDeleteYeah, the boy should have patented the idea. LOL
ReplyDeleteGreat article as always unk, I live in a heavily light polluted area (next to NYC) and even with 12" I can hardly see anything except a few bright objects, which quickly deflated my enthusiasm. What alternatives do someone like me who lives in a white zone have to look at some faint fuzzies. EAA or NV?? Dont know.
ReplyDeleteI kind of rolled my eyes when you stated your intention to run through the Messier list. I freely admit my error. Your excellent and honest descriptions of each object are interesting and valuable to me as an observer with less than fabulous optics. I guess my only minor suggestion would have been to cover them in order of current visibility instead of numerically. Thanks for the great blogs--I'm forever going back into your archives for info.
ReplyDelete