Uncle Rod's Astro Blog

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.