Meth99X
La Supernova 1999X dans CGCG 180-22 ou
PGC 25005
Tableaux des Mesures et Courbes
de Lumière
Éléments Indispensables pour le suivi
de la SN 1999X
Extrait de la circulaire IAUC 7105 du 6
février 1999
SUPERNOVA 1999X IN CGCG 180-22
M. Schwartz, Cottage Grove, OR, reports his discovery of an apparent supernova
(mag 16.1) on an unfiltered CCD frame taken on
Jan. 23.23 UT utilizing the Tenagra I 0.35-m automated supernova patrol
telescope in Sonoita, AZ, internet-controlled from Cottage
Grove. SN 1999X is located at R.A. = 8h54m32s.23, Decl. =+36o30'41".1
(equinox 2000.0), which is about 4".1 east and 5".5
north of the nucleus of CGCG 180-22. The new object was confirmed on a frame
taken on Jan. 27.13 at mag 15.3, showing significant
brightening. Schwartz adds that the object does not appear on either the first
or the second Palomar Sky Survey scans, and that
it is absent from the USNO A1.0 catalogue.
P. Garnavich, S. Jha, and R. Kirshner, Harvard-Smithsonian Center for
Astrophysics, report that a spectrum of SN 1999X was
obtained and reduced by P. Berlind (Fred L. Whipple Observatory) on Feb. 6.3 UT
using the Tillinghast telescope. The spectrum shows a strong Si II absorption
feature with a minimum at 629.6 nm,indicating that this is a type-Ia event.
Other features suggest an
age between 7 and 10 days past maximum light. The recession velocity of CGCG
180-22 is 7500 km/s (Ramella et al. 1995, A.J.
109, 1458), so that the supernova photospheric expansion velocity derived from
the Si II line is 10 050 km/s.
Image du champ de la SN 1999x avec repérage des étoiles USNO SA 2.0 et du GSC. L'étiquette de l'étoile représente la magnitude multipliée par 10.
Le suivi en images de la Supernova
1999x dans CGCG 180-22
L'image prise le 07/02/99 par Robin CHASSAGNE : sn99x-RC
L'image prise par Jean Marie LLAPASSET le 12/02/99 à 21h24m31s : s99x043
