[vsnet-campaign-sn 239] Spectral types for recent SNe

[Hitoshi YAMAOKA <yamaoka@rc.kyushu-u.ac.jp>]

Dear SN watchers,

  The IAUCs last week reported several spectral informations about
recent SNe.  

SN 2001ed:

>  M. Migliardi discovered a bright SN with 0.5-m CROSS telescope.
> The reported magnitude is far brighter than the expected maximum of 
> SN Ia from the recession velocity of the host galaxy NGC 706.  

  The spectrum obtained by the Danish 1.54-m telescope at ESO La Silla
on Sept. 9.257 and the CfA spectrum on Sept 11.42 show that SN 2001ed
is of type Ia several weeks after maximum light.  The ESO member 
estimates the age as 22 +/- 5 days after maximum.  (IAUC 7714)

  Comparing with the VSNET reports,

  20010821.000  147V  (Mt. Stromlo (from IAUC))
  20010822.130  145:C (P. Antonini)
  20010825.319  15.85C  (NEAT/MASS 1.2-m at Haleakala (from IAUC))
  20010825.360  15.85C  (NEAT/MASS 1.2-m at Haleakala (from IAUC))
  20010829.130  150:C (P. Antonini)
  20010902.960  149:C (M. Migliardi (from IAUC))
  20010903.010  149:C (M. Migliardi (from IAUC))
  20010908.105  158C  (C. Leyrat)

The maximum light was occured around Aug. 18 at mag about 14.5 or so.

> With this redshift measurement, Gellar and Huchra, 1983, ApJS, 52,
> 61 indicate that NGC 706 is a member of "group 21", as well as other
> members (NGC 741 and UGC 1395), whose mean recession velocity is
> 5069 km/s.  The expected maximum for this velocity is about mag
> 15.8, which is far dimmer than the one for SN 2001ed at discovery.  
> On the other hand, there is another group of galaxies in the same
> literature: "group 23" including NGC 676, NGC 693 and NGC 718.  The
> "group 21" and "group 23" is on the same direction but separated
> with the resemblance of the recession velocities.   
...
> The mean velocity of "group 23" is 1443 km/s.  

  The estimated maximum as mag 14.5 is coincident to the expected one
if the recession velocity is about 3000 km/s, which is about the mean
of the one for "group 21" and "group 23".


SN 2001ef:

>  The recession velocity of the host galaxy is 2476 km/s, from which 
> the expected maximum of the normal SN Ia is mag about 14.3.  The SN
> did not detected on the image taken by the discoverer on Aug. 29, so
> it seems to be something fresh.  On the other hand, the multicolor
> photometry at Apache Point observatory (Sept. 10.44) shows that it
> seems to be somewhat red.  It can be reddened by the interstellar
> (or circumstellar) matter.  

  This SN was turned out to be of SN Ic about a week after maximum on
Sept. 12 (IAUC 7714 reported as Ia but IAUC 7716 gave another
judgement), which is consistent with the reported magnitudes (mag
about 16.0 on Sept. 9-10). 


SN 2001eg:

> SN 2001eg is comparably dim object (mag 18-) although the host
> galaxy UGC 3885 is somewhat nearby galaxy (v_r = 3809 km/s).  

  This SN was turned out to be of SN Ia several months after maximum
(IAUC 7716).


SN 2001eh:

> SN 2001eh (discovered at mag 16.5) appears on a distant galaxy (v_r
> = 11103 km/s, expected maximum for SN Ia = mag 17.5), which seems to
> be somewhat overluminous. 

  This SN was turned out to be of SN Ia, and its spectrum taken on
Sept. 11 resembles to that of the overluminous SN Ia 1990N seven days
before maximum (IAUC 7714).  The reported magnitudes (the KAIT
discovered it independently) match to the overluminous SN Ia.

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

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