-------------------------------------------------------------------
THE ASTRONOMER Electronic Circular No 2776      2011 Oct 27 05.59UT
Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise,  Basingstoke,
Hants, RG22 4PP,England.Telephone/FAX(01256)471074Int:+441256471074
INTERNET: GUY@TAHQ.DEMON.CO.UK      Backup: gmh@wdcc1.bnsc.rl.ac.uk
WORLD WIDE WEB                         http://www.theastronomer.org
-------------------------------------------------------------------
URANUS
Larry Sromovsky from the University of Madison Wisconsin alerts that a 
very bright feature has appeared on Uranus. Detailed observations from 
the Gemini 8-m telescope show this feature at least 3 times brighter 
than the background of Uranus disk. If this is a convectively driven 
white feature it may evolve to larger size and brighter appearance on 
the next few days.

Images from amateurs are essential to study this feature and its precise 
drift rate to assist possible observation with other highly-priority 
telescopes such as the HST.

If you want to observe a distinct cloud feature on Uranus this is 
probably a very good opportunity to do it. Uranus subtends 3.7 arc 
seconds and the bright cloud feature is at least 0.33 arc seconds making 
this feature accessible to relatively modest telescopes. You can check 
the Gemini preliminary processed image at:

http://www.ajax.ehu.es/Uranus_Gemini_26oct2011_353nav.jpg

This image was provided by Larry Sromovsky and Patrick Fry and it 
includes a photometric cut of the CCD image showing the contrast of the 
bright feature. The image was acquired on 2011 October 26 at 08:06UT 
with the spot appearing at 323 west longitude and 22.5deg north.

The current best estimate for the longitudinal drift of this spot is 2 
deg/day +/-2deg/day westward starting from 351 W on 2011 Oct 26 at 8:18 
UT. The current estimate for the rotation period of this feature is: 
17.24 hr.

Please send, as a matter of urgency, any reports to the main Editor (for 
relay to professionals) and also a copy to Mark Kidger for the TA 
planetary column.

Guy M Hurst