SN1998S comparison stars etc. (Hanzl) Forwarded message by permission of Dr. Hanzl: From hanzl@sci.muni.cz Wed Apr 22 15:55 JST 1998 Date: Wed, 22 Apr 98 08:54:34 CST From: "Dalibor Hanzl" <hanzl@sci.muni.cz> Message-ID: <vsnet-alert1710@hoge.baba.hajime.jp> Reply-To: <hanzl@sci.muni.cz> Subject: SN 1998S - comparison stars CCD photomtry of stars from close surroudings of SN 1998S Dear Dr. Kato, I would like to inform you, that actual magnitude estimates of SNe, novae, active galactic nuclei (and eg. comets, too) by observers from Czech Republic are stored at WWW or ftp server http://astro.sci.muni.cz/cgi-bin/polozka/?novae or http://astro.sci.muni.cz/pub/news/ as file "novae". Observations from last year are available as file novae1997. Astronomical news events are at URL: http://astro.sci.muni.cz/hotnew.html. Here are database visual magnitude estimates of comets, some new CCD images SNe, etc. The page is actually only in Czech, but I hope, that in the future it will be in English version as well. As next I'm sending you my CCD photometry stars from close surroudings of SN 1998S which may be use as comparison stars for visual observations. Stars was measured during seven nights in V filter (+ CCD ST-7 + 0.40-m reflector at N. Copernicus Observatory and Planetarium, Brno, Czech Republic). Following mean value was derived from 35 independent measurement (except stars signed E and F, where I have photometry only from six nights (28 independent values). Comparison stars: GSC 3452.1093 with photometry from Tycho (output) Catalogue was used as: V = 9.87 +/- 0.04, B-V = 0.90 +/- 0.06 GSC number or position of comparison stars (if not given from GSC): B = GSC 3452.1091 C = GSC 3452.1101 D = GSC 3452.1061 E = - (R.A.=11h 45m 38s.0, Decl. = 47d 28' 18" E = 2000.0) F = GSC 3452.977 G = GSC 3452.978 H = GSC 3452.997 Position for "E" was taken from USNO A1.0 Catalogue. CCD photometry - Johnson V magnitude B C D E F G H V = 13.18 12.57 12.49 15.40 15.20 13.80 14.57 err = 0.02 0.02 0.01 0.06 0.05 0.02 0.04 sincerelly D. Hanzl