152P/Helin–Lawrence

Lore & Background

Both Helin and Lawrence discovered the diffuse trails of the comet from photographic plates exposed at 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.

The comet 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.

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 4.6 km in diameter, based on observations conducted using the Hubble and Keck telescopes in 1998.

Reader's Guide

The significance of 152P/Helin–Lawrence lies in its status as the third comet co-discovered by the prolific team of Eleanor F. Helin and Kenneth J. Lawrence, adding to the catalog of Jupiter-family comets. Its observational history includes a recovery in 2001 that documented its tail and coma dimensions, and a notable observation during the total lunar eclipse of 4 June 1995 by Robert H. McNaught. The comet's physical characteristics, particularly its continued activity at large heliocentric distances as revealed by 2012 polarimetric observations, suggest it is a relatively fresh object from the outer Solar System, rich in volatile materials. This implies that 152P/Helin–Lawrence has not yet undergone many close passages to the Sun, preserving its primordial ices. The nucleus size estimate of 4.6 km, derived from Hubble and Keck telescope observations in 1998, provides a baseline for understanding its structure. The comet's legacy is tied to these insights into the early Solar System's composition and the dynamics of Jupiter-family comets.

Did You Know?

• 152P/Helin–Lawrence is the third comet co-discovered by Eleanor F. Helin and Kenneth J. Lawrence.
• It was discovered from photographic plates exposed at Palomar Observatory on 17 May 1993.
• Its nucleus is estimated to be about 4.6 km in diameter based on 1998 Hubble and Keck observations.