Comet C/2015 F4 (Jacques)
Abstract
C. Jacques, Belo Horizonte, MG, Brazil, reports his discovery of a comet on CCD images taken by E. Pimentel, J. Barros, and himself with a 0.28-m f/2.2 astrograph at the SONEAR Observatory, Oliveira, Brazil (discovery observations tabulated below), the comet showing a condensed coma 8" in diameter. 2015 UT R.A. (2000) Decl. Mag. Observer Mar. 27.21144 19 43 13.58 -45 15 48.8 16.2 Jacques 27.22072 19 43 14.61 -45 15 43.6 16.4 " 27.22982 19 43 15.44 -45 15 39.5 16.6 " Fifteen stacked 60-s follow-up images taken remotely by Jacques et al. with an iTelescope 0.70-m f/6.6 astrograph at Siding Spring on Mar. 27.8 UT show a coma of diameter 8" with a tiny tail 17" long in p.a. 238 deg. After the comet was posted on the Minor Planet Center's PCCP webpage, other CCD astrometrists have commented on the object's cometary appearance. E. Guido and N. Howes stacked fourteen 60-s exposures taken remotely with an iTelescope 0.43-m f/6.8 astrograph at Siding Spring on Mar. 27.7, which show a sharp central condensation surrounded by a coma about 8" in diameter and a tail about 15" long in p.a. 237 deg. A. Chapman and N. D. Diaz stacked forty-five stacked 30-s exposures taken with a 0.20-m f/4 reflector at the Observatorio Cruz del Sur, San Justo, Buenos Aires, Argentina, on Mar. 28.3 to find a sharp central condensation surrounded by a coma. E. Bryssinck, Kruibeke, Belgium, writes that twelve stacked 120-s images taken remotely with a Tzec Maun 0.15-m f/7.3 refractor at Siding Spring on Mar. 28.74-28.77 show the comet to be strongly condensed with almost no coma visible (size about 13"; red magnitude 15.8) but with a clear tail about 48" long toward the southwest in p.a. 237 degrees. H. Sato, Tokyo, Japan, reports that four stacked 60-s exposures taken on Mar. 28.8 with an iTelescope 0.51-m f/6.8 astrograph (+ luminance filter) at Siding Spring shows the comet to be strongly condensed with an elongated coma of size 12" x 18" (w-band mag 15.7 as measured within a circular aperture of radius 8".8) with an 80" tail toward p.a. 250 degrees. The available astrometry, the following preliminary parabolic orbital elements by G. V. Williams, and an ephemeris appear on MPEC 2015-F159. T = 2015 Aug. 8.2015 TT Peri. = 31.6381 Node = 286.9965 2000.0 q = 1.734964 AU Incl. = 47.8222
- Publication:
-
Central Bureau Electronic Telegrams
- Pub Date:
- March 2015
- Bibcode:
- 2015CBET.4085....1J