Bird, wildlife, and landscape photography by Jon Rista
Comet Lovejoy – C/2013 R1
First shot of Comet Lovejoy. Not much to look at, but it’s still a little exciting, after all the hullabaloo about ISON. I took a whole bunch of shots, and I’m going to try to stack them, see if I can get a better result.
Comet ISON has apparently brightened by a factor of 10 over the last few hours. It has moved into negative magnitude territory. As of now, they are saying it is still there, has not broken up, and is around mag -1 to -1.2. Magnitude is a logarithmic scale, where positive numbers indicate increasing dimness, and negative numbers indicate increasing brightness. To put that in context, Saturn at it’s brightest has a magnitude of 0. Jupiter currently has a magnitude of almost -3. The dimmest stars the human eye can see have a magnitude of 6. The full moon has a magnitude of -13, and a half moon is around -5. Until we lost view of it due to the morning twilight, Comet ISON had a magnitude of around 4, so slightly brighter than the dimmest stars visible to the naked eye (which can only be seen on truly DARK nights under DARK skies…i.e. a hundred miles or so from the nearest town or city, preferably at altitude.)
So, Comet ISON having increased in brightness to mag -1.2 means it is getting pretty bright. The original expectations were for it to reach mag -5.5, being a little brighter than the moon in the morning sky. While it could very well reach this brightness while it is very close to the sun, it is doubtful it will be that bright when it emerges and is visible to the naked eye again. Whatever Comet ISON does (survive or fragment), at it’s current rate of increasing brightness, it should remain brighter than it was for a few days in December. So, in the early morning, you might get a decent show with a comet that is between mag -1 and -3 (about as bright as jupiter is now, which is pretty bright) until maybe Dec. 3rd or 4th. Beyond that, especially if the comet fragments, it will dim back to mag 4 and lower and disappear pretty quick.