MASDB2 identified with the man-made object
D. Denisenko, V. Lipunov (Moscow State University, Sternberg Astronomical Institute)
MASDB2 = TA29DCF

A slowly moving 16-mag object MASDB2 detected by MASTER-Amur robotic telescope was reported in ATel #5610. Between 17:45 and 18:46 UT on 2013 Nov. 28 the object was moving at approximately 12" per hour (2-3 times slower than the Main Belt asteroids and ~150 times slower than the Moon). However, it was not found in MASTER-Kislovodsk follow up images (field of view 2x2 deg.) obtained on 21:50 and 22:20 UT.

Following the private communication by K. Sokolovsky, we have checked the Minor Planet Center's Distant Artificial Satellites Observation Page. Ephemerides of eleven objects were obtained for 2013 Nov. 28 using [D54] observatory code of MASTER-Amur (the remaining eleven were Outside range of available ephemeris data). One of those objects with available ephemeris named TA29DCF matched the observations of MASDB2 within 15' accuracy in position, 1.5m in brightness and, what is mostly important, in the slow motion (about 0.2" per minute, or 0.2' per hour). Here is the excerpt of the ephemeris provided by DASO Page (date, azimuth and elevation omitted):

A little investigation in Google has shown that TA29DCF is actually an upper stage of RadioAstron (Spektr-R) telescope developed by the Astro Space Center of the Lebedev Physical Institute and launched into high-apogee orbit on 2011 July 18. The latest orbit computation by Bill Gray on 2013 Nov. 19 gives the following parameters: a=175314 km, e=0.9428776, i=6.55675, q=10014 km, Q=340614 km, P=8.46d, H=27.9. Additional information can be found in Minor Planet Mailing List message [MPML 29194] and in DASO Circulars.

We thank Kirill Sokolovsky (ASC Lebedev/SAI MSU) for his useful advice. We apologize for any troubles caused by our original announcement in ATel and at the NEO Confirmation Page.
optical,asteroid,near-earth object,planet,a comment