Tuesday 8 June 2010

2010 May notes: MACE 2010, (130) Elektra occultation and 2010 KQ

After a four year gap since the last "Meeting on Asteroids and Comets in Europe" (MACE) in Vienna in 2006, the 5th MACE took place in Visnjan/Tican, Croatia during 21-23 May (http://www.minorplanets.org/MACE2010/). Richard Miles and I attended from the UK and in all about 50 amateur and professional astronomers from all over Europe attended, together with Steve Chesley/JPL from the USA. Richard and I had the pleasure of meeting Jan Vales (P/2010 H2), discussing at length with him and others Richard's ideas on possible mechanisms that may have caused the dramatic outburst that led to Jan's discovery. The meeting also boasted comet discoverers Michel Ory (P/2008 Q2) and Eric Elst (133P/Elst-Pizarro), Korado Korlevic (183P/Korlevic-Juric and 203P/Korlevic) and of course the meeting organizer Reiner Stoss, co-founder of the La Sagra Sky Survey team that is credited with comets P/2009 QG31, P/2009 T2 and P/2009 WJ50.

Following on from the (130) Elektra result (TA 551,299), another occultation was successfully captured from Great Shefford, this time of the mag +10.5 star TYC 5573-00543-1 by (80) Sappho on June 4. The drift-scan image shows the starlight being blocked out by the minor planet for 5.5 seconds and revealing the minor planet shining faintly at mag. +11.8. John Broughton's SCANALYZER software was used to reduce the time of disappearance and reappearance (see full details here). At least one other UK observer, Tim Haymes in Maidenhead, Berkshire is also known to have succeeded in obtaining a positive result and other results are expected from France and Italy, which may lead to a determination of the asteroid's shape when all the results are in.

As well as a few very close approaches by newly discovered minor planets (the closest being 2010 JV39 to 0.65 Lunar Distances (LD) on May 26 and 2010 JL88 to 1 LD on May 17) there was also the discovery of unusual object 2010 KQ, originally added to the Minor Planet Center's NEO Confirmation page (NEOCP) on May 16 and observed from Great Shefford on the evening of May 17. Soon after my positions were sent in to the Minor Planet Center, Associate Director Gareth Williams removed it from the NEOCP with a note "was not a minor planet", adding it instead to his "Distant Artificial Satellites Observation Page" at http://www.minorplanetcenter.org/iau/SpaceJunk/SpaceJunk.html and indicated to me that further observations would still be useful. I got another set of measures the next night and sent them in to the MPC as Artificial Satellite positions. The next day all the positions obtained from discovery to May 18 were published in MPEC 2010-K15, announcing the object as minor planet 2010 KQ! It would approach the Earth to within 1.28 LD on May 21 and then gradually drift away, in an orbit quite similar to the Earth's (q=0.997 AU, P=396 days, e=0.055).
In the next week, spectral measurements were obtained by Richard Miles using the 2.0 Faulkes Telescope North and S.J. Bus using the NASA IRTF telescope, both on Hawaii and both observers determined independently that the spectrum of 2010 KQ does not match any known asteroid type, but is very similar to space weathered titanium dioxide paint and conclude that 2010 KQ is in fact very likely to be artificial. With further positional observations made in June it appears that the object made a very close approach to Earth in 1975, but it has not yet been possible to definitively match it to a spacecraft launch near that time.