C/1999 J6 (SOHO) is a small comet, notable for being among those that made a close approach to the Earth.[2][3][4][5] It was first observed by the space-based Solar and Heliospheric Observatory (SOHO) on 10 May 1995.[6][7] It is next expected to come to perihelion (closest approach to the Sun) in June 2026 at 0.044 AU (6.6 million km).[1]
The most notable Earth approach was on June 12, 1999 when it passed between 357,000 km (222,000 mi) to 3.3 million kilometres (2,100,000 mi) from Earth.[3] The uncertainty is a result of the large number of observations at roughly the same time as there were around 50 observations on April 19, 2010. The discovery was made on March 20, 2000, during a review of previously captured images.[8]
It next came to perihelion in November 2004, when it was known as "C/2004 V9",[9] and then on April 19, 2010 when it was known as "C/2010 H3".[10][11] On August 15, 2015 it should have been 0.56 AU from Earth.[12]
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Mike Oates (January 17, 2005). "Mike's SOHO Comet Hunt: Non-Sungrazing Comets". Archived from the original on March 6, 2017. Retrieved December 15, 2018. Found on the evening of March 21 2000 while searching archive data from the LASCO C3 instrument on FITS images taken on May 11 1999. The comet was seen moving away from the Sun, getting brighter then fading, it could be followed on the May 12th images as well. Doug Biesecker also located the comet on C2 frames on the 10th.
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Matthew M. Knight. "Studies of SOHO Comets"(PDF). p. 167. Archived(PDF) from the original on October 26, 2017. Retrieved December 15, 2018. The only comet which was observed well enough to compare the lightcurve shapes was C/1999 J6 which returned as C/2004 V9.
^"The Return of C/1999 J6 = C/2004 V9". Archived from the original on October 25, 2018. Retrieved December 15, 2018. The two brightest Marsden group comets C/1999 J6 and C/2004 V9 were linked by Brian Marsden (MPEC 2004-X73) and Z. Sekanina and P. W. Chodas, an orbit for the 2010 return by S. Nakano is here.
