(IAAC) Object: M92 Instrument: 16" Dob

Observer:  Todd Gross
Your skill:  Intermediate +
Date and UT of observation: 2/4/97 0900 GMT
Location & latitude: 22 miles west of Boston, Ma. 42.3N
Site classification: Suburban

Limiting magnitude (visual): 5 (estimated),  5 (est)  in vicinity of object
Seeing (1 to 5 - best to worst):  3
Moon up (phase?): Yes, 20%, near horizon

Instrument: f/4.59 16" Dob, f.l. 1839mm, excellent optics, 
96-99% coating, 3.1"secondary

Magnifications:  175x, 97x
Filters used: none
Object:  M92
Constellation: Hercules
Object data: Globular Cluster

Description: Like most notable globulars in this scope, (M13, M5, M3) this is 
one of the best sights I have seen in astronomy. At 97x M92 is clearly
resolved to the core, unlike smaller aperture scopes, which in my
semi-light polluted evironment have difficulty with the core at this
"lower" magnification.  

The center is more compact than some other globulars but was broken down 
into stars in the foreground right to the core. THERE WAS A DISTINTIVE "S"
to the stars coming out of M92's core, making it look quite 3-D in 
appearance. In fact, I was so startled at seeing the letter "S" that I double 
checked the effect. The angle of view through the Dob was just right to make
the "S"
appear exactly straight up.  I did not take the time to figure out which way
was North.

At 175x the globular looked even more broken down,
but marginal seeing made for blurry stars at times, so I went back to
97x. Excellent object, particularly satisfying from my suburban location where
extended objects wash out more. I also looked at M13, and it's strings of stars
during the same observing session, and while M92 is not as large, it is
almost as
enjoyable with this aperture.

- Todd
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Email: toddg@weatherman.com    Work Phone# (617)725-0777