Thursday, August 15, 2013

Bright Nova in Delphinus

Some 36 hours ago, a nova appeared in Delphinus, which has rapidly brightened to fifth magnitude. It is near the planetary nebula NGC-6905, which is easy for a 6-inch from a good site. This is apparently a fast nova, one which brightens very rapidly and fades almost as quickly, and there has been no known previous outbursts. That makes it a classical nova. I do not know the distance to the system, which will reveal the luminosity of both the nova and the two stars that gave rise to it. However, the star system was at 17th magnitude before the explosion, and it is very far away from Earth, at least 12,000 light years and possibly nearly twice that. Below is a drawing I made last night through a hole in the clouds. The nova is very conspicuous because no fifth magnitude star exists at its position, and it shines with a yellowish white color. As it fades, it will likely gradually yellow then redden before fading to normal, where it will be a very faint, hot blue or white star. To make this drawing I used my 10-inch F/4.5 Dob with a 24mm Explore Scientific 82 degree eyepiece. The pair yield a magnification of 55X with a Televue coma corrector in place and a true field of view about 1.5 degree across. The planetary nebula is also quite conspicuous, with about 45 arc-minutes separating nova from the planetary nebula. This nova is going to start fading very soon, if you wish to see it, don't delay. Below is a link to an article that will show you where to look for Nova Delphini 2013.

http://www.skyandtelescope.com/observing/home/Bright-Nova-in-Delphinus-219631281.html