------------------------------------------------------------------- THE ASTRONOMER Electronic Circular No 2134 2005 Jly 30 12.03UT 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 GMH at AST.STAR.RL.AC.UK WORLD WIDE WEB http://www.theastronomer.org ------------------------------------------------------------------- 2003 UB313 Mike E. Brown, C. A. Trujillo and D. Rabinowitz, 1.2-m Oschin Schmidt + CCD at Palomar Mountain/NEAT (station 644) report their discovery of 2003 UB313, an asteroid at about 97 AU, on M. P. E. C. 2005-O41 as follows: 2003 10 21.26747 01 36 13.82 -06 07 15.3 18.8 R EO041644 2003 10 21.33840 01 36 13.67 -06 07 16.1 18.8 R EO041644 2003 10 21.40306 01 36 13.53 -06 07 16.8 18.8 R EO041644 2005 01 08.06424 01 34 44.08 -05 51 58.2 18.4 R EO041807 2005 01 09.07007 01 34 43.86 -05 51 47.3 18.4 R EO041807 2005 01 10.08784 01 34 43.69 -05 51 36.0 18.4 R EO041807 In addition Brown and his team have measured an image of 1989 Sept 29 obtained at Siding Spring-DSS and reported measurements at Cerro Tololo (807). Orbital elements from MPEC 2005-041: Epoch 2005 Aug. 18.0 TT = JDT 2453600.5 MPC M 197.53790 (2000.0) P Q n 0.00176902 Peri. 151.31153 -0.91258509 -0.02028701 a 67.7091000 Node 35.87500 -0.34877687 -0.48266077 e 0.4416129 Incl. 44.17700 +0.21340843 -0.87557240 P 557 H -1.1 G 0.15 U 5 The absolute magnitude, H =-1.1 is higher than Pluto. Mike Brown quotes on his website: "Usually when we find these we do not know their size for certain, only lower limits. The lower limit to this object is the size of Pluto. This object is at least the size of Pluto and likely a bit larger." This is the basis of the announcements by NASA and the Media today of the discovery of a 10th planet although definitions of such, including Pluto, are still being debated. The IAU have not yet announced a name despite the many rumours circulating on the Internet. Ephemeris: Date TT R. A. (2000) Decl. Delta r Elong. Phase V 2005 07 29 01 39.38 -05 19.3 96.681 96.939 104.4 0.6 18.9 2005 08 08 01 39.30 -05 21.0 96.526 96.937 113.7 0.5 18.9 2005 08 18 01 39.16 -05 22.9 96.382 96.936 122.9 0.5 18.9 2005 08 28 01 38.97 -05 25.0 96.254 96.934 132.1 0.4 18.8 2005 09 07 01 38.72 -05 27.3 96.146 96.933 141.2 0.4 18.8 2003 EL61 In addition to the above announcement news has been circulating that the supposed '10th planet' was, in fact, 2003 EL61 also referred to on Mike Brown's website. However M. P. E. C. 2005-O36 makes it clear this was found by F. J. Aceituno and measured by P. Santos-Sanz and J. L. Ortiz from exposures on 2003 October 21 using a 0.36-m f/6 Schmidt-Cassegrain + CCD at Sierra Nevada Observatory (station J86): 2003 03 09.01612 13 19 56.32 +20 40 29.8 17.7 V EO036J86 2003 03 10.01530 13 19 53.05 +20 41 06.4 17.6 V EO036J86 The H value on this object is 0.4. Guy M Hurst