Sunday, January 29, 2006

20060128 - Starhopping for Clusters & Galaxies

Session Names: 20060127.2110; 20060128.2120

Location: TotL, Central Park, NYC
Site Classification: Urban
Dates/times: 27 Jan. 2006, 9:10pm ~ Midnight; 27 Jan. 2006, 9:10pm ~ 12:15am
Handheld Binos: Fuji 7x50
Tripod-mounted Binos: Takahashi 22x60, fov - 2.1°
Tripod-mounted RFT: Coulter CT-100, F/4 4¼" reflector


Transparency/Seeing (1 worst - 5 best): 2/3
NELM: Zenith - m4.66 (gamma Cancri)
Conditions: Moonless, clear night, mild, ocassional light breezes
Observing party: Myself
Passersby: Hawaiian George, Carol & friends, Kin with Times Up! (about 6 riders), a few other pedestrians


Saturday was a warm, beautiful day. The sky was clear during the day, but there were differing weather forecasts. I happened out around 8:00pm to see that it was clear, so I put my money on
Clear Sky Clock. Taking the same observing pack I tool out last night, I set out to TotL for another night of observing. The air was still warm that I dressed in sweater and turtleneck, carrying my coat for later in the evening. Once again, I thought for sure others would be out but I observed mostly on my own. A nice way to get back in the groove and feel the *zone*. Around 10:30pm, it would become busy with pedestrians coming by.

This night I felt more productive than the previous day. Perhaps, it was because the increased number of objects observed but hopping was much more fluid. Armed with
Karkoschka's atlas, and PleiadAtlas on the Palm Tungsten T3, I had a plan. I concentrated on Canis Major. Sirius was situated well a bit east of the Citibank building; this is nearly celestial South.

I open cluster-hopped from
M41 south to Collinder 121, east to NGC 2354 & NGC 2362, and further east to M93. At the time I was observing M93, Hawaiian George appeared. We observed Saturn & M44, and then back to M41 as a comparison for size, brightness, and stellar richness. To me, M44 exhibits a greater range of brightness than M41, as well size and quantity of visible stars through binoculars. I could easily count 28 stars in M41 compared to the 40+ stars in M44. This evening, I couldn't see Rhea near Saturn, in spite of knowing where to look. Titan was bold situated to the East.

Collinder 121 was difficult to identify. Locating omicron CMa was a cinch, though looking in the field I didn't see any noticeable concentration. Referencing PleiadAtlas, I could see the scattering of brighter stars with omicron CMa to the North and an obvious broken line of stars running South. I searched along east long that line. At reported 50' in size, this should be huge. I've yet to research this but I would say to pass on this cluster unless one wants to complete a list.

While nearby, I went South to Adhara, epsilon CMa, a double with a 7.5" separation according to Karkoschka. I was unable to resolve.

One of favorite open clusters in the telescope is NGC 2362, tau CMa Cluster. I think I've seen it referred to as the "Mexican Jumping Cluster". It's a beautiful, tight compact cluster of diamond dust surrounding bright tau CMa, most of the concentration to the east & south of tau CMa. However, through the bins, a lot is to be desired. I did count 7 stars surrounding the east-south-west, none to the north. Additionally, there was a faint haze below these stars, though difficult. While there, I noted that beta Lyrae-type variable 29 CMa appeared almost equally as bright as tau CMa, but slightly dimmer.

Nearby I tried for NGC 2354 but was unable to positively detect it. For that matter, I didn't even suspect anything. After spending some time hoping to dark adapt in the EP, I panned east counting about 3 field of views (~ 6°), when M93 appeared. It took me a while to id this cluster because I sort of lost my bearings. retracing my steps it was certainly M93. Only 2 stars resolved clearly, a third blinked to the north, with a very faint glow beneath. Compared with the urban background sky, this cluster was obvious despite that it didn't resolve well nor glow brightly. Again much more impressive in a scope.

Times Up came stopped by on their monthly Central Park Midnight ride. They were pretty thin with about 6 riders, Kin being one of them. I showed a couple of them the obvious sight and would collapse the tripod for one of the riders’ son. He got a little tour from Saturn to A beautiful sight of Orion's Sword to Sirius. Orion's Sword frames very, very, well in the Tak's fov. One can see
NGC 1981 down to iota^1 & -^2, the nebula stood up well even though we were looking a bit west of Time's Square’s Gegenschein. Simply beautiful and thought provoking.

The crowd cleared and I was left to my own a bit past 11pm. I got courageous and hunted the brighter galaxies. Of the list that I searched - NGC 2841, M81, M82, NGC 2903 - only M81 & M82 were detectable in the bins. Seeing the sigma-sigma-rho triangle and 24 UMa naked eye, it was easy to land at where I needed to be. M82 appeared as unfocused star at first, making an almost equilateral triangle with 2 stars to the west. When looking for M82, which was extremely difficult, M81 appeared much larger than an unfocused star with averted as an extended glow. It was difficult to give it any orientation in length, rather it was ball~ish. M82 was glimpsed about three times with averted only, though I could detect that its orientation was nearly parallel with two brighter stars to the east.

My favorite astro-sketcher,
Kiminori Ikebe captures a field similar to what I observed though his objects are brighter. NGC 3077 was not observed. Check out his English pages for some nice work. And for the adventurous or fluent, his Japanese pages offer much more.

Getting late, on my own, and seeing some clouds move in from the west I began to wind down. I did a quick hit in Auriga, glancing at Leaping Minnows, Cheshire Cat, M38 and M36. As I looked M38, a ribbon of smoke floated through the field. Looking up a cloud front was moving through. After seeing M36 totally resolved (and more attractive than M38), I tried for M37 but the clouds moved in. Stretching from West to Northeast, the clouds came making the decision to pack that much easier.

All-in-all a good 3 hours of observing and sharing. Bins are light, fun, and useful, but I like the scope much better. Being able to magnify and the larger glass grasping more light really enhances the experience. In spite of serving myself, I feel a little awkward when the regular passersby come through and all there is is the little package. My own aperture envy :^D