* Astronomy

(136849) 1998 CS1 was discovered by A. Nakamura at Kuma Kogen Observatory (Japan) on February 9, 1998.  It will approach within 0.0291 AU (11.3 lunar distances) on January 17, 2009.
Its absolute magnitude of 17.7 suggests a diameter within a factor of two of 0.9 km.
Spectroscopy obtained by M. D. Hicks and K. Lawrence at Palomar indicates that it's an Sq-type object.  Lightcurves obtained by Joe Pollock (Appalachian State University) reveal a 2.6-hour rotation period with an amplitude of about 0.2 magnitudes, suggestive of a shape with low-to-moderate elongation.  Subsequent lightcurves obtained by Michael Hicks and Heath Rhoades at Table Mountain Observatory have revealed a consistent synodic rotation period of 2.7 hours.

Read more

The asteroid is predicted to appear at magnitude 12; currently moving through Ursa Major towards Leo.
Closest approach at 18:00 GMT, January 17, 2009.

Ephemeris

              Equatorial coordinates            
    Date      Hour        RA            DEC       Mag       
             (UTC)     h  m  s        d  '  "             
 =========== ======  =============  ============ ===== 
 15 Jan 2009 18.733   11 34 54.277  +28 48 25.67  12.3    
 16 Jan 2009 18.733   12 49 46.988  +30 29 37.02  12.4    
 17 Jan 2009 18.733   14 23  2.961  +28 50 15.81  12.9     
 18 Jan 2009 18.733   15 49 38.547  +23 28 24.04  13.8    
 19 Jan 2009 18.733   16 52 35.873  +17 13  7.44  15.0     
 20 Jan 2009 18.733   17 34 32.503  +12  3  0.34  16.3    
 21 Jan 2009 18.733   18  2 46.640  + 8 12 32.46  17.3     
 22 Jan 2009 18.733   18 22 33.757  + 5 23 18.29  18.2     
 23 Jan 2009 18.733   18 37  1.717  + 3 16 38.16  19.0     
 24 Jan 2009 18.733   18 48  0.708  + 1 39 14.64  19.6     
 25 Jan 2009 18.733   18 56 37.324  + 0 22 18.98  20.1     
 26 Jan 2009 18.733   19  3 33.457  - 0 39 58.13  20.5     
 27 Jan 2009 18.733   19  9 16.520  - 1 31 31.41  20.8    
 28 Jan 2009 18.733   19 14  5.112  - 2 15  2.32  21.1    
 29 Jan 2009 18.733   19 18 12.260  - 2 52 24.60  21.3   
 30 Jan 2009 18.733   19 21 47.358  - 3 25  0.16  21.4    
 31 Jan 2009 18.733   19 24 57.351  - 3 53 49.25  21.5     

-- Edited by Blobrana at 18:01, 2009-01-15