Astronomy, Photography and Weather

General Category => Astronomy & Space => Topic started by: martinastro on July 15, 2008, 02:48:36 pm



Title: C/2006 OF2 Broughton
Post by: martinastro on July 15, 2008, 02:48:36 pm
Yet another comet visible from the northern hemisphere is C/2006 OF2 Broughton. This comet has recently been observed at mag + 11.9 at the end of June so it should now be brigther for visual observers using large reflectors. Currently visible low in the NE pre-dawn sky and located between Andromeda and Perseus. The comet is expected to peak at mag + 10.5 and will remain visible until 2009. Worth hunting down when the sky gets darker.

Wide field chart...

(http://i34.tinypic.com/2ez5kqo.gif)

Deep finder chart from skyhound...

http://www.skyhound.com/cometchasing/comets/2006_OF2.gif

Ephemeris

http://cfa-www.harvard.edu/iau/Ephemerides/Comets/2006OF2.html


Title: Re: C/2006 OF2 Broughton
Post by: Paul on July 15, 2008, 02:59:05 pm
Gosh, another Comet! This is a good time for the sky to start getting darker, and let's hope the clouds start to clear too!


Title: Re: C/2006 OF2 Broughton
Post by: brianb on July 15, 2008, 03:25:00 pm
Well the ephemeris in the BAA Handbook estimates around 12.0 at the end of June so it's behaving itself. Unfortunately the same ephemeris shows it getting no brighter than 10.8 (in early Nov, when it's in the Camelopardalis area).

The one to look forward to at the end of the year seems to be 85P/Boethin which is predicted to be mag. 7.4 moving North through Aquarius in mid-December.

Of course a really bright comet could appear more or less anywhere at any time ...


Title: Re: C/2006 OF2 Broughton
Post by: martinastro on July 16, 2008, 07:20:47 pm
I was thinking the very same thing Brian. We are long over due a bright comet in the northern hemisphere. I'm keeping my fingers crossed there will be a new discovery very soon.  :)


Title: Re: C/2006 OF2 Broughton
Post by: brianb on July 16, 2008, 07:30:09 pm
Quote
We are long over due a bright comet in the northern hemisphere.
Forgotten Holmes already?  :o


Title: Re: C/2006 OF2 Broughton
Post by: martinastro on July 17, 2008, 06:44:34 pm
Holmes was great wasn't it?. That comet gave me so many nights of happiness.

I would like to see a proper great comet with bright dust tail. Even though I seen McNaught with the naked eye both in the evening and morning, it was seen in poor conditions.

I've always wanted to see a proper sungrazer like this guy...

http://cometography.com/lcomets/1811f1.html


Title: Re: C/2006 OF2 Broughton
Post by: Roman White on July 20, 2008, 10:14:21 am
Yes, we weren't expecting for anything special in Nov 2007 and voila - the Holmes comet arrived! It's unforgottable!

Could someone explain me why the trajectory of C/2006 OF2 make such a sharp angle in Nov 2008?


Title: Re: C/2006 OF2 Broughton
Post by: martinastro on July 20, 2008, 07:16:39 pm
Good question Roman. No doubt the sudden change in direction is due to the Comet-Earth geometry changing during the months as the comet orbits the Sun, and Earth orbits the Sun, but at different rates. The comet looks to be experiencing some kind of retrograde motion similar to what happens with Mars when the Earth overtakes the planet/comet in it's orbit.

I'm guessing that's what's happening here although an expert in orbits would be able to explain it better.


Title: Re: C/2006 OF2 Broughton
Post by: Roman White on July 21, 2008, 11:50:55 am
Good question Roman. No doubt the sudden change in direction is due to the Comet-Earth geometry changing during the months as the comet orbits the Sun, and Earth orbits the Sun, but at different rates. The comet looks to be experiencing some kind of retrograde motion similar to what happens with Mars when the Earth overtakes the planet/comet in it's orbit.
I'm guessing that's what's happening here although an expert in orbits would be able to explain it better.
I understand it but not at all.

More simple question. When I look at the trajectory of Mercury, I sometimes see  #1 or #2 kinds of trajectory.
(http://s48.radikal.ru/i122/0807/d0/2017857cefe9.gif) (http://www.radikal.ru)
I can somehow explain #1, but what about the #2, the same as the C/2006OF2 ?