[vsnet-obs 10620] (fwd) Re: SN1998T (update)

[Taichi Kato <tkato>]

Forwarded message from Stan Howerton on SN 1998T (relayed by permission):

From Phwcomdso@horizon.hit.net Tue Mar 24 08:59 JST 1998
Date: Mon, 23 Mar 1998 18:03:28 -0600
From: Stan Howerton <Phwcomdso@horizon.hit.net>
Subject: Re: SN1998T (update)

Taichi Kato wrote:
> 
> SN1998T (update)
> 
>   YYMMDD(UT)   mag  observer
>   980306.644  <133  (S. Takahashi)
>   980307.644  <133  (H. Maehara)
>   980307.650  <142  (S. Takahashi)
>   980307.708   142  (S. Kidachi)
>   980309.880   144: (T. Kinnunen)
>   980315.819   144  (T. Kinnunen)
>   980317.790   143  (T. Kinnunen)
>   980318.790   144  (T. Kinnunen)
>   980319.790   144  (T. Kinnunen)
>   980321.810   144  (T. Kinnunen)
>   980322.628   144  (S. Kidachi)

These estimates are fainter than what I observed.  So far I have made
visual observations on two nights.  On March 21, 6:02 UT I felt it was
about magnitude 13.0 because of two clues.  First it was slightly
brighter than GSC 3831 795 for which Guide 6.0 gives a magnitude of
13.2.  I realize the magnitude for this comparison star may not be
accurate.  However the supernova stood out with averted vision through
my 33cm at 202x.  If it were a magnitude fainter it would not have been
so obvious.

On March 22, 5:20 UT it was noticeably fainter. I estimated it was about
13.5, but thought this might be a little too bright.  However it was
still much brighter than GSC 3831 688 for which Guide 6.0 lists at
magnitude 14.5.  I viewed this star with some difficulty due to
suspected high clouds.

My estimates for SN 1998S for these two nights were 11.6 and 11.7
respectably as it appeared brighter than data per the ISN for GSC 3452
1149 (11.8) and GSC 3452 905 (11.9).

Stan Howerton
hwcomdso@horizon.hit.net

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