Comet C/2017 D3 (Atlas)
Abstract
Henry Weiland, University of Hawaii, on behalf of the "Asteroid Terrestrial-impact Last Alert System" (ATLAS) Team, reports the discovery of a comet on four c-band exposures taken with the ATLAS 0.5-m f/2.0 Schmidt telescope at Haleakala (discovery observations tabulated below). Four stacked exposures show that the comet has a size of 7".7 (well larger than the sizes of nearby stars). 2017 UT R.A. (2000) Decl. Mag. Feb. 23.60692 13 25 53.87 -35 31 25.1 18.0 23.62203 13 25 53.12 -35 31 17.9 18.1 23.63716 13 25 52.33 -35 31 12.5 17.9 23.65233 13 25 51.48 -35 31 07.3 18.0 After the comet was posted on the Minor Planet Center's PCCP webpage, other CCD astrometrists reported on the cometary appearance. Three stacked 60-s exposures taken by C. Jacques, E. Pimentel, and J. Barros on Feb. 24.2 UT with a 0.45-m f/2.9 reflector at the SONEAR Observatory at Oliveira, Brazil, show a diffuse coma of diameter 13" with a central condensation and red mag 18.1-18.3. Four stacked images obtained by S. Foglia, L. Buzzi, P. Concari, C. Cremaschini, G. Galli, and M. Tombelli with an iTelescope 0.15-m f/7 refractor at Siding Spring on Feb. 24.5 show a coma 10" in diameter and red mag 17.7-17.8; three additional stacked images obtained in the same manner on Feb. 27.6 also show a 10" coma but a brighter red magnitude of 17.1-17.2. H. Sato, Tokyo, Japan, writes that eight stacked 60-s exposures taken on Feb. 24.6 with an iTelescope 0.51-m f/6.8 astrograph (+ luminance filter) show a strongly condensed coma 15" in diameter and a 20" tail toward p.a. 200 degrees; the w-band magnitude was 16.6 as measured within a circular aperture of radius 8".2.
- Publication:
-
Central Bureau Electronic Telegrams
- Pub Date:
- March 2017
- Bibcode:
- 2017CBET.4367....1J