SN 2001bg : Bright type Ia supernova reaching 13th mag

SN 2001bg was discovered on May 8 when it was mag about 14. The next day it was confirmed at the almost same magnitude. The reported position is 22" east and 19" south of the center of the barred-spiral galaxy NGC 2608. NGC 2608 is somewhat nearby galaxy. Its recession velocity is about 2100 km/s. de Vaucouleurs and Peters (1984 ApJ, 287, 1) lists this galaxy as m-M = 31.24, nearly the same as the Virgo cluster. And, this galaxy produced another SN 1920A, which was observed as mag about 12.0. This magnitude is slightly brighter than the typical SN Ia maximum in the Virgo cluster (vsnet-campaign-sn 179). H. Kawakita, K. Kinugasa, and H. Yamaoka reported to CBAT that they performed spectroscopy at Gunma observatory and showed this SN was of type Ia near the maximum (vsnet-campaign-sn 180). After it remained at around 13.7mag for a few days (vsnet-campaign-sn 194), The object started gradual fading (vsnet-campaign-sn 199). The CfA group also took a spectrum, which shows deep absorption lines by the interstellar medium both in the host galaxy and in our Galaxy (IAUC 7626). It suggests that SN 2001bg suffers a deep extinction (A_V ~ 2 mag), and the expected maximum was overestimated (vsnet-campaign-sn 204).

Other related articles: vsnet-campaign-sn 181, 182, 184, 187, 198, 202