Comet C/2017 T2 (Panstarrs)
Abstract
An object (with only marginal cometary appearance that was not initially noticed) that was discovered on CCD exposures taken with the 1.8-m Pan-STARRS1 telescope at Haleakala on Oct. 2 and 10 UT (discovery astrometry tabulated below, together with earlier Pan-STARRS1 observations found subsequently) was found later to show cometary appearance. After the object was moved to the Minor Planet Center's PCCP webpage (following initial posting on its NEOCP webpage), R. Weryk (Institute for Astronomy, University of Hawaii) reported that neither the Oct. 2 nor the Oct. 10 images indicate a tail present, but the full-width-at-half-maximum of the comet's image is 1".7 (in 1".0 and 1".3 seeing, respectively). There appears to be no cometary activity visible in the Sept. 15 images, which were taken in poor seeing (about 2".2). 2017 UT R.A. (2000) Decl. Mag. Sept.15.58688 3 36 21.45 -14 57 56.4 20.3 15.59883 3 36 21.32 -14 57 58.3 20.2 15.61079 3 36 21.21 -14 58 00.3 20.2 15.62277 3 36 21.09 -14 58 02.3 20.3 Oct. 2.52110 3 32 39.34 -15 43 31.4 19.9 2.53268 3 32 39.15 -15 43 33.3 19.8 2.54430 3 32 38.94 -15 43 35.0 19.9 2.55589 3 32 38.75 -15 43 36.9 19.8 10.53922 3 30 12.02 -16 03 19.8 19.7 10.55237 3 30 11.74 -16 03 21.6 19.7 10.56555 3 30 11.49 -16 03 23.4 19.6 10.57869 3 30 11.21 -16 03 25.3 19.6 After the object was initially posted on the Minor Planet Center's NEOCP webpage, H. Sato (Tokyo, Japan) wrote that ten stacked 60-s CCD exposures taken on Oct. 12.57 UT with an iTelescope 0.51-m f/6.8 astrograph at Siding Spring, NSW, show a strongly condensed coma 6" in diameter with no tail; the total w-band magnitude was 19.3 as measured within a circular aperture of radius 4".9. R. J. Wainscoat examined the object on five 60-s w-band exposures taken on Oct. 21.52-21.53 with the 3.6-m Canada-France-Hawaii Telescope at Mauna Kea (queue observer D. Woodworth), which show the comet to be extended (FWHM = 1".3 in 0".75 seeing); in each image, the object appeared to be slightly asymmetric, with a very faint low-surface-brightness extension to the northwest (and the magnitude was measured by M. Micheli to be 19.4-19.6). Weryk adds that additional Pan-STARRS1 images taken on Oct. 22.5 show a very short tail extending about 0".5 towards the northwest. J.-F. Soulier obtained 120 sixty-second unfiltered CCD exposures with a 0.20-m f/4 Newtonian reflector at the Observatoire Chante-Perdrix near Dauban, France, on Oct. 16.04-16.11, which show a coma around 12" in size and a tail about 20" long in p.a. 290 deg; he measured red mag 19.5 in an aperture of radius 6".6.
- Publication:
-
Central Bureau Electronic Telegrams
- Pub Date:
- October 2017
- Bibcode:
- 2017CBET.4445....1W