[BAA 00523] Close pass of bright near-Earth asteroid, 2003 UV11

[Rick]

BAA electronic bulletin No. 00523 -- http://www.britastro.org/
Bulletin transmitted on Mon Oct 25 13:13:14 BST 2010
(c) 2010 British Astronomical Association

2003 UV11, a relatively large near-Earth asteroid measuring roughly 400-500 meters across, is currently making a close approach over the next few days. In so doing it will become one of the brightest such objects for several years attaining a V magnitude of about 11.9 on October 29 and passing closest to the Earth at a range of 5.0 lunar-distances on 2010 October 30 at 04:14 UT.

Although we know the orbit of this object with high accuracy and details of this close approach have been listed in the BAA Handbook for 2010 (p.55), we do not know a great deal about its physical nature including its rotation period.  The close pass therefore represents an excellent opportunity for observers to obtain images suitable for photometry.  From the UK, the most favourable observing times (UT) will be the nights of Oct 26/27 (20h-03h),  Oct 27/28 (20h-03h), and in particular the two nights of Thursday, Oct 28/29 (19h-02h) and Friday, Oct 29/30 (18h-0h) when it will reach magnitude 12 and be moving at 50-60 arcsec/min and 130-160 arcsec/min respectively.  Visual observation through a telescope on the last night should also prove very rewarding as it will then be possible to see it moving in real-time - a rare opportunity for such a bright target!

Exact positions for your location can be obtained by going to either the  Minor Planet & Comet Ephemeris Service at: http://www.minorplanetcenter.org/iau/MPEph/MPEph.html or the JPL HORIZONS interface at: http://ssd.jpl.nasa.gov/horizons.cgi#top

Do let me know if you are able to obtain good quality images.  For photometry, exposure times are best kept short although short trails can  still be used.  Near closest approach, exposure times of up to 20 sec should be fine.  (N.B. Longer times are helpful in that the reference stars are recorded with good signal-to-noise.)  Fortunately for observers, the object is favourably placed well south of the Milky Way sweeping through the constellations of Aries, Pisces and Pegasus where the starfields are not too crowded.

Good luck and clear skies,

Richard Miles
Director, Asteroids and Remote Planets Section

[MarkS]

That seems to put it near the star Sheratan in the constellation of Aries this evening (Wed 27 Oct).