(meteorobs) Stargazing at State/National Parks out west

[bmccurdy at telusplanet.net]

Quoting Skywayinc at aol.com:

>  
> In a message dated 3/22/2007 2:53:58 AM Eastern Daylight Time,  
> bmccurdy at telusplanet.net writes:
> 
> The  Saskatchewan 
> Summer Star Party will be taking place in beautiful Cypress  Hills 
> Interprovincial Park, located at Latitude 49.652 deg. N, Longitude  109.521 
> deg. W . SSSP is scheduled for August 9-12, 2007, perfectly timed  for the 
> Perseids. 
 
> But at lattitude 49.6N the nights must be awfully short; my
> guess is that astronomical twilight ends at around 11 p.m, and begins  
> sometime around 2 or 3 in the morning.  

   According to the RASC Observer's Handbook, on Aug 8 astronomical twilight 
for 50 deg north ends at 21:55 and begins at 2:13 (not corrected for longitude 
or for DST, which is not enacted in Saskatchewan in any event). On Aug 18 
(next entry in the table) that extends from 21:25 to 2:41, so the night of 
Perseid max would feature about 4 hours and 40 minutes of astronomical 
darkness. And as Jan points out, the shallow sun angle allows additional hours 
of deep nautical twilight. 

   From way up here in the Late Light North (53.5 deg. N. latitude), 49.6 
sounds like south to me! Even here in Edmonton we traditionally observe the 
Perseids from 11 p.m. to 5 a.m. (MDT), with only the last hour significantly 
compromised but worth doing due to the favourable position of the radiant 
which by then is approaching the zenith. Another northern advantage -- which 
we take wherever we can find them -- is that the Perseid radiant (58 N.) is 
comfortably circumpolar and is well up in the sky right from the onset of 
darkness.  

   With my tongue firmly lodged in my cheek I will suggest that five hours of 
dark skies is preferable to eight hours of clouds. :) SSSP is a heck of a nice 
star party too; consider yourself invited. 

   Bruce
   *****