[AZ-Observing] Re: Moon Dog over SE AZ this evening

I also noticed a dramatic halo at 3 a.m. Tuesday morning.  These are 22-degree 
moon halos ... 22 degrees in radius, that is.  A "moon dog," or paraselene, is 
something different -- the moonlight equivalent of a sun dog, or parhelion.  
According to the book "Color and Light in Nature" by David K. Lynch and William 
Livingston (an excellent reference), "The 46-degree (sun) halo ... occurs far 
less frequently than the 22-degree halo and, because of its large size, is 
seldom if ever observed as a complete circle ... Observations of the 46-degree 
parhelia are rare and perhaps questionable."  I imagine observations of the 
fainter 46-degree moon halo and moon dogs are rarer still.
   
  --Joe Orman
   
  There is a very nice Moon Dog (46 degrees) outside right now. Capella, 
Aldebaran, an Mars are all within the halo.

http://www.pbase.com/pegsam/image/89491221

Sam 




--
See message header for info on list archives or unsubscribing, and please 
send personal replies to the author, not the list.

Other related posts: