[vsnet-chat 1219] (fwd) On SN1998dm (Howerton)

[Taichi Kato <tkato>]

From hwcomdso@horizon.hit.net Sun Aug 30 21:10 JST 1998
From: "Stan Howerton" <hwcomdso@horizon.hit.net>
Subject: Re: SN1998dm and SN1998dn images/charts
Date: Sun, 30 Aug 1998 07:13:27 -0500

I viewed MCG+01-04-044 at approximately 9:30 UT (4:30 a.m. CDT) August 30,
1998 with a 13.1" (33.3cm) f/4.5 dobsonian at 202x.  After making a visual
examination of the field, I have concluded there is some incorrect
information as to the exact position of the galaxy MCG-01-04-044.

The chart provided at the address listed below incorrectly positions the
galaxy.  Furthermore, my software (Guide 6.0) also plots the galaxy at the
same position (1h 26.319m, -6d 4.433m).  Both show a star (GSC 4684 1696 per
Guide 6.0) in the south-southwestern tip of the galaxy when this star
actually lies some 1/2' following the northeastern tip of the galaxy.
However, an examination of the software RealSky reveals a position of
approximately 1h 26m 14s, -6d 5m 44s for the galaxy.

Others may make the same mistake I did this morning in believing there is a
foreground star in the SSW tip and be frustrated in not being able to detect
the supernova when, in fact, this star is probably the supernova.

Thus if I am correct, the only star visible in the SSW tip of MCG+01-04-044
is SN1998dm.  Since I mistook it for a foreground star I did not make an
estimate of its brightness.  However, I had made a mental note that it was
about 14.0 to 14.5 as I was wondering why this "foreground" star was much
fainter than expected.

Am I correct in my conclusion?



>   Masao Funada has provided a GIF chart of SN1998dm
>
>  http://ftp.kusastro.kyoto-u.ac.jp/pub/vsnet/SNe/sn1998dm/funada.gif
>
>Regards,
>Taichi Kato
>
>

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