Return to Home Page
Date: Thu, 12 Aug 93 17:34:49 CDT From: gav@astro.as.utexas.edu (Gerard de Vaucouleurs) Subject: SN93J Dear Dr. Kato: The following record in your latest listing should be deleted 1992.10.02 / 20.0 R / Humpreys, R. / KPNO 0.9-m, CCD / Nova Dr. Humphreys informs me that she does not have an observation on that date. There must be confusion with the entry just above it (Salzer et al.), to which the KPNO CCD reference must apply. The spelling of her name should be corrected in the 1982 and 1985 entries and she did not have a V plate in 1985 (this must have been deduced from B and R by interpolation). In 1982 the B and V magnitudes are for March 21, the U and R for March 23. The magnitudes themselves have been revised also, but have not been released yet. She and Dr. Richmond are finishing a paper on the progenitor star in which they also revise the other CCD data of Perelmuter, Magnier and others. If and when I have her permission to do so I will send you the revised values. Mr. J.-C. Merlin has been able to revise his image-tube observations of March 27.91, 1993. In collaboration with Mr. Buil (of Toulouse, France) they composited 3 pictures to reduce photographic noise and lower the detection limit. They now can see the 17.8 V mag star 25" N of the SN, but there is no trace of the SN itself. Because of the color sensitivity of the unfiltered image-tube and the color difference between the read star and the presumably blue fireball (if onset was before JD 074.4) one cannot conclude that the SN was then fainter than 17.8, but it is most likely that V > 17.0 is a safe limit, possibly V > 17.5. So the symbol [16.0 in yur listing should be replaced at least by [17.0 (posibly 17.5) [corrections: your listing, ... possibly]. Mr. Merlin is now attempting to determine the color equation of his unfiltered image-tube to refine the numbers above. So we now know that onset was between JD74.4 and 74.8 (Neely's revised data). In fact I believe that to = JD74.5 +/- 0.05. With best regards, G. de Vaucouleurs
Return to the Daisaku
vsnet-adm@kusastro.kyoto-u.ac.jp
