152P/Helin–Lawrence is a Jupiter-family comet with a 9.51-year orbit around the Sun. It is the third comet co-discovered by Eleanor F. Helin and Kenneth J. Lawrence.
Observational history Both Helin and Lawrence discovered the diffuse trails of the comet from the photographic plates exposed from the Palomar Observatory on the night of 17 May 1993. At the time, it was a 17th-magnitude object within the constellation Scorpio. Shortly after the announcement of its discovery, Robert H. McNaught was able to observe it during the total lunar eclipse of 4 June 1995.
It was recovered from the Saji Observatory by T. Oribe and Shuichi Nakano on 24 December 2001, where Oribe reported that the comet had an 8 arcsecond-long tail. On 11 January 2002, the comet showed a diffuse coma about 8 arcseconds wide and a tail about 13 arcseconds in length.
Physical characteristics Polarimetric observations from the European Southern Observatory in 2012 revealed that both 74P/Smirnova–Chernykh and 152P/Helin–Lawrence still produce cometary activity even at large heliocentric distances, suggesting that both comets were relative newcomers to the inner Solar System and thus contain large reservoirs of volatile material in their respective interiors.
The nucleus of 152P/Helin–Lawrence is estimated to be around in diameter, based on observations conducted using the Hubble and Keck telescopes in 1998.
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References
External links
at the Minor Planet Center database 152P/Helin–Lawrence at Gary W. Kronk's Cometography 152P/Helin–Lawrence at Seiichi Yoshida's website