The Other Double Double in Lyra

  Last evening I was out observing with a telescope and thinking about how another
summer is ending and the fall season is upon us. With the exception of the month
of August which was mostly cloudy and rainy, the summer here was a good one for
observing. The first three weeks of September has been a welcome return to the
good observing nights like I experienced in June and July. At a public open
viewing night this past Friday I was showing the attendees the famous double
double ( Epsilon 1and 2 Lyrae). At the end of the evening I realized I had
forgotten to show them the other double double in eastern Lyra with the wider
separation and nearly parallel components rather than perpendicular as with
epsilon 1 and 2. I have never sketched this combination of double stars so I
decided to do just that and maybe next time I won’t forget to point out this view.
I am not a binocular observer but these stars would I am sure look great and split
nicely in a pair of astronomical  binoculars. The northern pair of stars are designated
Struve 2470 they are both white stars at magnitudes 6.6 and 8.6 at a position angle
of 271°. The separation of this pair is 13.4” of arc. The other double pair 11 minutes
to the south is Struve 2474; this pair of pale yellow stars glow at magnitude 6.7 and 8.7.
they are separated by 16” of arc and are in position angle 262°. This is the way they
looked to me at the telescope eyepiece. These stars are about 19hrs. 9min.
Right Ascensionand +34° 40min Declination. Both pair fit nicely in one field of
view and are easy to split.
  
  Sketching:
  
  Date and Time: 9-20-2007, 2:25-2:50 UT
  Scope: 10” f/5.7 Dobsonian. 21mm eyepiece 70x
  8”x12” white sketching paper, B, 2B graphite pencils, scanned and inverted, star
  brightness adjustment using Paint
  Seeing: Pickering 7/10
  Transparency: above average 3/5
  Nelm: 4.5
  
  Frank McCabe