Tuesday, August 14, 2007

20070813 - Globular Clusters were stunning

Session name: 20070813.2120

Coming off a long and rewarding experience with the previous Saturday/Sunday session and knowing from the forecast that the week ahead was not looking good, I decided to observe this Monday evening again with the Teleport 10" reflector. I sent Charlie email but received no reply. Shortly after I arrived Charlie showed up with bins and tripod. As we setup in the usual spot, we chatted about good Saturday was and looked forwad to the night ahead.

Tonight the seeing was phenomenal! For a summer sky - or any season sky - this was a clear, steady, transparent night. Never having assigned a perfect rating for Seeing or Transparency, this was as good as it gets. I was looking at Jupiter with exceptional clarity.

I was a little confused (and still am) at what I saw. In recent observations with the Tak refractor (north up, mirror reversed), I've called the dark thick band easily observed the Northern Equatorial Belt (NEB). I have been unable to the see the Southern Equatorial Belt nor the Great (pale) Red Spot because of poor seeing conditions. This session Charlie and I could see the prominent NEB and three partial belts on the southern hemispere. Parts of the SEB as well as the Southern Tropical Belt, Southern Temperate Belt, the Southern Polar Hood and the interleaving zones were all seen clearly. On the northern hemisphere, the NEB and the Northern Polar region were the two remarkable features. However, when I looked at the marked up photograph of Jupiter in Peterson Field Guide Stars and Planets, it appears that the northern hemisphere belts are more contrasty and dark, whereas the south is pale and subdued. In the 10" reflector, north should be on the bottom, thus leaving me an impression from Peterson's that contradicts notes and memory. Maybe I got it all wrong in my notebook so I'll wait for another evening.

The ecliptic and Jupiter are low in the southern sky. The Dob felt as if it was horizntal and being too close it was looking through the fence surrounding the lawn. I moved the scope across the sidewalk and Charlie asked if I was setting up there. It was temporary for Jupiter and the scope would go back to the normal side. While Charlie and I were observing Jupiter in the scope two dog owners and their dogs came up. Unleashed the dogs began to play in our area and close to Charlie's gear. The dogs began rough housing and one, maybe both, knocked Charlie's tripod. One owner tried to reach for the tripod but missed sending his bins to the ground. Charlie quickly recovered the bins and setup thre tripod but the bins turned out to be damaged. No broken glass, but scratches on the housing an dthe optics were totaly out of alignment. What a shame!

If it wasn't for the magnificent views of the globular clusters it could have been a downer all evening long. Remarkably, Charlie didn't lose much spirit (or he didn't show it) and we continued to observe into the wee hours like last session leaving at 3:30AM.

M57 in the 10" is unlike looking through the 4" refractor or taking the challenge of find it in 50mm - 60mm optics. The Ring Nebula is that bright, fanciful smoke ring that all could see clearly, even the pedestrians. While in Lyra, we observed epsilon Lyr, the Double Double but slightly disagreed on the resolution. This pair is bright for a 10" reflector and the glare from the stars can be a nusance. Charlie saw pinching and tangentailly touching pairs; I saw each double fully resolved in the same orientation as he. Afterwards, pushed the scope to Albireo, Beta Cyg, the beautiful golden yellow and blue pair. Nudging the scope towards Sulafat, gamma Lyr, found M56 in short order. M56 is a faint globular cluster where maybe 3 stars resolved above a fiant, pale glow.

A couple passed by and stopped. The young woman told us how her father builds research-grade telescopes for a living and that she has had many experiences looking through scopes and visiting observatories. I don't think her male friend has the least bit of experience. She agreed that M56 was a faint fuzzy and he struggled to find it. For his benefit, I swung the scope to M13 (photo at Atsromick), the Great Hercules Globular Cluster, where he could observe another of its kind. With a faint, consistent glow, stars were popping out. This globular was 3-D. At Charlie's suggestion, we threw M92 in the eyepiece. Wow!! that globular cluster, though smaller, was much brighter and exhibited more detail and variation in its brightness profile than M13. Like M13 this globular resolved beautifully like a fireworks cluster halted in time. Diamond chips on to top of diamond chips.

Sagittarius was directly south for us, that is seeting in the celestial southwest sky. Typically, I stop on M22 but this session I stopped on M28 since we were doing the globulars. This was nondescript, a challenge to the discerning eye but not worthwhile like the previous ones. Pushed teh scope up higher in the sky to locate M24 but found it to be a large sparse scattering of some bright stars. I've never gotten a view of this star cloud that I could appreciate.

With the Fall sky rising and the Perseids still around, I decided to look manhattan-north, the area of the sky we call The Corridor. This section of sky falls roughly between celestial North and East and is the darkest part of sky line. This is where Charlie and I have seen 12 ~ 13 stars of Pleiades and on good nights a NELM of ~5.2 without a hint of the Milky Way (that is naked eye, in optics is another story.)