[vsnet-chat 258] Re: observing season of Mira (omicron Cet)

[Fraser Farrell <fraserf@dove.net.au>]

On 1997-04-19 b.h.granslo@astro.uio.no said:
   >The longest Mira season (349 days) occurs at lat. 54.5 deg. S.

Not much land at that latitude, or clear nights.  A friend of mine who
has worked extensively on sub-Antarctic islands says you can wait weeks
to get a glimpse of the Sun, never mind stars!

   >In order to observe Mira for as long as possible it is of course
   >necessary to have a transparent atmosphere and an unobstructed
   >view in the appropriate direction.

Late March and April skies here are typically either: (a) cloudy & wet,
due to approaching winter, or (b) hazy, due to dust blowing from
drought-stricken farms.  May is effectively the start of winter too.

   >In addition, it is important to correct brightness
   >estimates for extinction when the star is very low in the sky.

Now _that_ is the hard part.  Cloud coming off open ocean at night is
hard to detect, and it can move in within minutes around here.


This reminds me of a Sky & Telescope article I read some time ago,
concerning the number of bright stars visible from various latitudes.
Has anyone done the same calculation for GCVS objects?




cheers,
Fraser Farrell

http://vsnet.dove.net.au/~fraserf/   email: fraserf@dove.net.au
traditional: PO Box 332, Christies Beach, SA  5165, Australia

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