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(IAAC) Obj: Gamma Virginis (Porrima) - Inst: 80mm f/8 Fluorite refractor on Polaris mount
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Observation Poster: Bill Becker <bbe51@rmisp.com>
Observer: Bill Becker
Your skills: Advanced (many years)
Date/time of observation: May 3, 2002 3:45 UT
Location of site: Casper Wyoming USA (Lat 42*50'17.4", Elev 1700 meters)
Site classification: Exurban
Sky darkness: 5 <Limiting magnitude>
Seeing: 7 <1-10 Seeing Scale (10 best)>
Moon presence: None - moon not in sky
Instrument: 80mm f/8 Fluorite refractor on Polaris mount
Magnification: 213x 7.5mm Tal LE & 2.5x Powermate
Filter(s): none
Object(s): Gamma Virginis (Porrima)
Category: Multiple star.
Class:
Constellation: Virgo
Data: mag size
Position: RA : DEC :
Description:
Hi all!
Well, the clouds, snow and rain finally departed and the
temperatures are(knock on wood) starting to resemble what can be called
seasonable. A little bit of wind occurred throughout this observing
session but it had near zero effect on the images I was seeing through
the scope. I'd estimate that for +50% of the time, the seeing was nice
and steady and it doesn't get much better than that from my locale.;^)
My sole purpose tonight was to see what the heck I could do with Porrima
using an 80 mm refractor. At ~1" of arc separation, I knew my "success"
would be limited due to the 3"ers resolution limit but having a double
with such equal components(in magnitude) I figured if I could see any
evidence of duplicity, it would reaffirm my belief that this scopes
optics are top notch. I was not disappointed. ;^)
I found a definite elongation(so close to direct E-W)of the star using a
7.5mm Tak LE & 2.5x Powermate(213x) Just to double check the validity of
this observation, I trained the scope on a couple of other stars,
including Spica, and they appeared as perfect pinpoints so I'm convinced
I saw what I saw.
At this power, the yellowish colour(seen at lesser magnification) pretty
much disappeared and the best I can describe it is as off white. I spent
a good 40 minutes experimenting at different mags and found that, on
this particular night, the 213x was optimum.
I know there are a lot of small aperture scope users here...I'd
love to see how you fare.
Best regards,
Bill
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