[Chaos-l] Observing 8/4/2010

[Jon Stewart-Taylor]

Hi all.  Yesterday i said:

> [...]  Anybody interested in a quick Jordan Lake trip?  [...] t i'm  
> thinking i'll go out there for at least a couple hours after sunset.

So i went, and it was an OK night for summer.  Got there a bit before  
dark, stayed 'till about 11:30. There was pleasantly little traffic  
(Wednesday night, after all), but pretty much the whole night the  
north and east flashed with "heat lightning", i.e. thunderstorms so  
far away i couldn't hear the thunder.  Clouds came and went, and i  
observed around them.

My primary goal was to find the triple star Struve 2816. This time of  
year it takes a while for Cepheus to rise out of the Durham skyglow,  
so i had some time to kill.  While i was waiting, i worked my way  
through the July and August "Telescopic Tour" list of objects from Guy  
Ottewell's  _Astronomical Calendar_.  Each month's Telescopic Tour is  
list of double stars and brighter deep-sky objects easily observable  
from about 9 pm to 10 pm in the middle of the month.  As you'd expect,  
the Messier objects in the summer Milky Way are featured this time of  
year.

With the waxing and waning clouds, i couldn't follow the exact  
sequence of the Tour, but i worked my way through about the first half  
of both lists (there was considerable overlap, of course). I was using  
a copy of Wil Tirion's _The Cambridge Star Atlas_ which i'd checked  
out of the library to hunt things down (review of _TCSA_ to follow).   
In general, it was a fine reference to find things, especially with  
the 8x50 finder.

Around quarter of eleven Cepheus was both high enough and cloudless  
enough that i could start my hunt for Struve 2816.  The first thing i  
look at in Cepheus is usually mu, the famous "Garnet Star".  The color  
is easily visible in the 8x50 finders, and very pretty through the  
main 'scope.  Struve 2816 is near mu, in the large but faint cluster  
IC1396.  It's the brightest star at the center of the cluster, and  
turned out to be a beautiful color-contrasting triple.  The primary is  
a golden yellow, with the two fainter companions to either side a blue- 
tinted white.  It kinda reminded me of a Chesire Cat smile.  Here's a  
link to a fairly good drawing, but it doesn't really do it justice:

http://www.cloudynights.com/ubbthreads/attachments/3913386-Struve-2816.jpg

For fun, there's another Struve double in the same low-power (45x)  
field of view, also part of IC 1396.  The cluster itself would be a  
better target for a wide (2+ degree) fov instrument.

At about 11:15, another wave of clouds passed through, and i packed it  
up and went home.  The best viewing of the night was suppose to be  
from 1 am to 3 am, but i'd already bagged my prey, and i needed to get  
up at a reasonable hour to job-hunt some more.  On the way home i  
drove through sprinkles.  Shortly after arriving a real thunderstorm  
broke out.  It might not have hit further south at the lake, but  
reinforced the feeling that i'd quit at the right time.

J.
-- 
Jon Stewart-Taylor:  joncst at earthlink.net
Chapel Hill Astronomy: http://www.rtpnet.org/chaos