[Message Prev][Message Next][Thread Prev][Thread Next][Message Index][Thread Index]

[vsolj-alert 113] Re: Possible SN in M96



山岡@九大理 です。

> この辺で山岡さんにバトンタッチかな?

と言われても、それほど付け加える情報はないですが……。

母銀河NGC 3688 = M96 は、Sab型の渦巻銀河で、しし座銀河群に属しています。
距離は8.1Mpcとでていました。Ia型なら極大で10等台が期待できますし、それ
以外でもかなり明るくなります。距離はSN 1993J (M81)以後では最も近いもの
です。あ、1994Iのほうが近いかも知れない(でもあれは暗かったから……)。

超新星は銀河の腕のちょっと濃いあたり(HII region?)にあるそうです。今の
ところ、12.5等くらいですね。

これまでのまとめを以下に付けます。

>To: vsnet-alert@kusastro.kyoto-u.ac.jp
Subject: Re: Supernova in NGC 3368 = Messier 96
Cc: yamaoka, nomoto@astron.s.u-tokyo.ac.jp, pah@quaser.physik.unibas.ch,
        alex@wormhole.berkeley.edu
Status: R

Dear SN fans,

  There appears the nearest supernovae in these five years! 
My article intends to summarize the information available up to now.

  Mirko Villi, Italy has discovered an apparent supernova (mag about
13.5) on the CCD image he had taken on May 9.9 UT in NGC 3368 =
Messier 96. He reports that it locates about 50" north of the center
of the host galaxy.  Visual confirmation was made by B. Skiff, at
Lowell observatory on May 10.33 UT. There has been no
preveously-existing stars up to 18 mag, nor any known bright
asteroids. 

  Preliminary astrometry was brought out by Yasuo Sano, Nayoro
Observaroty, Hokkaido, Japan, which gives the position of the new star
as R.A. = 10h46m46s, Decl = +11o50'07" (2000.0, using 11 GSC stars), 
which is about 49" north (east-west offset is not certain because of
the accuracy but it should be less than 7") from the center of the
host. It agrees with Mirko's position. 

  Magnitude estimates up to now:

UT(YYMMDD)  mag    observer
980509.9    13.5C  Villi
980510.33   12.5:  Skiff (visual)
980510.48   12.49C Sano

which indicate a remarkable brightning in about a half-day. 

  The host galaxy (type Sab) belongs to Leo group and the distance of
it has been estimated as 8.1 Mpc for H_0 = 75 km s-1 Mpc-1 (Turry,
Nearby Galaxy Catalog). It is a nearest supernova after SN 1993J.  If
it is of type Ia, it can reach 10.7 mag on its maximum. Also, it is
nearer than (bright) SN Ia 1991T. Spectroscopy had not carried on
(it crouds almost all Japan without Hokkaido...).   The observation
with wide wavelength is deadly urged. 

Sincerely Yours,
Hitoshi Yamaoka, Kyushu Univ., Japan
yamaoka@rc.kyushu-u.ac.jp

P.S. Please forward this article to anyone who would be interested.

VSNET Home Page

Return to Daisaku Nogami


vsnet-adm@kusastro.kyoto-u.ac.jp