Meth99gj
La SN1999gj dans Ngc 3521
Tableau de
Mesures et Courbe de
lumière
Extrait de la circulaire IAUC 7330
SUPERNOVA 1999gj IN NGC 3251
G. M. Hurst, Basingstoke, England, reports the discovery by Mark Armstrong,
Rolvenden, of a supernova located at R.A. =
10h29m19s.27, Decl. = +26o06'19".2 (equinox 2000.0; average of two
measurements, from Nov. 17 and Dec. 8 frames), which was noted to
be 40" east and slightly south of the nucleus of NGC 3251. The supernova
appears on three of Armstrong's CCD frames, with the
following magnitudes being estimated: Nov. 17.20 UT, 17.5; Dec. 2.14, 18.0;
8.16, 18.0. The object is not present on the first or
second Palomar Sky Surveys (limiting mag about 20). P. Garnavich, S. Jha, R.
Kirshner, and P. Challis, Harvard-
Smithsonian Center for Astrophysics, report that a spectrum of SN 1999gj was
obtained by A. Mahdavi with the F. L. Whipple
Observatory (FLWO) 1.5-m Tillinghast telescope on Dec. 9.5 UT. This shows the
new object to be a type-Ia event, between 1 and 2
months after maximum light. Narrow emission lines from the host galaxy give a
recession velocity of 5300 km/s. CCD images obtained
with the FLWO 1.2-m telescope near Dec. 9.5 yield V about 19.0 for SN 1999gj.
Position end figures derived from the CCD images (based
on the HST Guide Star Catalog) are 19s.20, 20".2, which is 33" east
and 21" north of the galaxy nucleus.
Le suivi en images de la SN1999gj
dans Ngc 3521
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S99gjCH1 000109 R CHASSAGNE |
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