268P/Bernardi

Past, Present, and Future Orbits by Kazuo Kinoshita

L. Buzzi image of 268P exposed on 2005 November 12

This image was acquired on 2005 November 12.19, using a 60-cm f/6 reflector. It is composed of 26 60-second exposures. The nuclear magnitude was determined as 20.0.

Discovery

Fabrizio Bernardi discovered this comet on images taken with the Canada-France-Hawaii Telescope (Mauna Kea, Hawaii, USA). The comet showed a very faint tail extending as much as 12" in about PA 290 deg. and the magnitude was made in a 3.7" photometric aperture. Images obtained by H. Hsieh on Nov. 4.6 UT with the 224-cm reflector at Mauna Kea also show the tail. The point-spread function of the comet's head was consistently about 0.3" larger than stars of similar brightness.

Historical Highlights

The first orbit released for this comet was a parabolic one computed by Brian G. Marsden (Central Bureau for Astronomical Telegrams) and published on IAU Circular 8627 (2005 November 04). Based on positions gathered during the period of 2005 November 1-4, he determined the perihelion date as 2005 September 3.11 and the perihelion distance as 2.45 AU.The low inclination prompted Marsden to suggest the comet was "probably of short period." On November 14 the Central Bureau issued MPEC 2005-V94. It indicated that further observations had confirmed Marsden's suggestion that the comet was moving in a short-period orbit. Based on 17 positions obtained during the period of November 1-12, Marsden determined a perihelion date of 2005 August 17.20, a perihelion distance of 2.37 AU, and an orbital period of 10.8 years.

S. Nakano improved the orbital elements using 35 positions from 2005 November 1 to 2006 April 28. Perturbations by Mercury to Neptune and three minor planets, Ceres, Pallas and Vesta, were taken into account. He found a perihelion date of 2005 August 12.57, a perihelion distance of 2.35, and an orbital period of 9.58 years.

Nakano predicted the comet would return in 2015. The comet was recovered in 2012 and give the preliminary designation of P/2012 P2. It was recovered on 2012 August 13 by David J. Tholen's team while using the 8.2-m Suburu Telescope on Mauna Kea (Hawaii, USA). The magnitude was given as 24. The recovery was confirmed on August 16 by the same observers.

The 2015 apparitions was characterized by few observations caused by the poor brightness.

Additional Images

J.-F. Soulier image of 268P exposed on 2014 December 24

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