[AZ-Observing] Re: Quick look at gamma Vir in the Lowell Clark
- From: Brian Skiff <Brian.Skiff@xxxxxxxxxx>
- To: az-observing@xxxxxxxxxxxxx
- Date: Thu, 27 May 2004 12:23:47 -0700 (MST)
>> Year Distance PA
...
>> 2004.00 0.63 216
>> 2004.25 0.56 208
>> 2004.50 0.50 198
>> 2004.75 0.43 185
Perhaps I was being too pessimistic about the separation versus
aperture, but my impression was that the current separation must be
something like 0".7 to 0".8, whereas the ephemeris is showing 0".5
right now. John and I estimated pa200, so no problem there.
The last actual observations shown at the USNO-DC double-star site
are from a couple years ago:
2000.3403 258.8 . 1.41
2001.3202 252.7 . 1.22
2002.252 244.6 . 1.02
Anyway, if 0".5 is right, then maybe we were doing better than we thought
in terms of seeing/resolution. It was obviously double though not
resolved at 6-inches aperture. S.W. Burnham _discovered_ pairs at that
separation with his 6-inch refractor way-back-when, so it _is_ possible
to see pairs that close.
Though the motion isn't as fast as, say, a comet, the fact that
the position angle is changing from ~200 now to ~135 next spring will
be comparatively dramatic when you consider these are stars orbiting
each other. As long as you can see the pair elongated, the shift in
angle should be visually evident despite them being unresolved.
\Brian
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