Comet P/2017 S8 (Panstarrs)

After the comet was posted on the Minor Planet Center's PCCP webpage, other CCD astrometrists also reported cometary appearance. H. Sato, Tokyo, Japan, obtained eight stacked 60-s exposures with an iTelescope 0.61-m f/6.5 astrograph at the Sierra Remote Observatory near Auberry, CA, USA, on Oct. 2.53 UT that show a moderately condensed coma 8" in diameter with a 20" tail toward p.a. 265 degrees; the total w-band magnitude was 19.5 as measured within a circular aperture of radius 5".0. A. F. Tubbiolo obtained 55-s exposures with the Steward Observatory 0.9-m f/3 reflector at Kitt Peak on Oct. 12.4 in 1".5 seeing that show a tail extending about 15" in p.a. approximately 175 deg. K. Sarneczky, Konkoly Observatory, writes that nine stacked 90-s unfiltered CCD images taken with the 1.02-m Ritchey-Chretien telescope at Piszkesteto, Hungary, on Oct. 14.0 show a nearly stellar coma and a slighly curved tail about 15" long in p.a. about 280 deg; the red magnitude of the coma was 19.2 as measured within a circular aperture of radius 3".0. Forty-eight co-added 30-s exposures taken by P. Bacci and M. Maestripieri (and measured by Bacci with L. Tesi and G. Fagioli) with a 0.60-m f/4 reflector at San Marcello Pistoiese, Italy, apparently show a diffuse coma and 16" tail in p.a. 300 deg. R. A. Mastaler finds a tail in p.a. approximately 290 degrees on four stacked 90-s exposures taken on Oct. 21.3 with the Spacewatch II 1.8-m f/2.7 reflector; a nearby bright star prevented determination of the tail length. Eight stacked 120-s exposures taken by E. Bryssinck (Kruibeke, Belgium) with an iTelescope 0.51-m f/4.5 reflector near Mayhill, NM, USA, on Oct. 25.36 show a condensed, starlike appearance and an elongated shape of size 8" x 12" toward the west (p.a. 276 deg); the magnitude was R = 19.0. Four co-added 30-s exposures taken by G. J. Leonard with the Mount Lemmon 1.5-m reflector on Oct. 26.3 show a narrow tail 15" long in p.a. 295 deg. D. C. Fuls notes that images taken on Oct. 26.36 with the Steward Observatory 1.0-m reflector at Mount Lemmon show a clear tail in p.a. 290 deg.