[vsnet-chat 1231] (fwd) MGC+01-04044 confusion GUIDE (Rodriguez)

[Taichi Kato <tkato>]

(fwd) MGC+01-04044 confusion GUIDE (Rodriguez)

From DRODRIG@santandersupernet.com Tue Sep  1 08:06 JST 1998
From: "Diego Rodriguez" <DRODRIG@santandersupernet.com>
Subject: RV: MGC+01-04044 confusion  GUIDE
Date: Tue, 1 Sep 1998 08:46:07 +0200

Incorrect Information Guide 6.0

Sorry  Taichi.
I have concluded there is some incorrect information as to the exact
position  of the galaxy MCG+01-04-044.in  my software (Guide 6.0)

Information of  MGC+01-04-044 Alternate name = PGC 5072
Right ascension: 01h23m18.92s
Declination: +07 47' 38.4"


Information of  MGC+01-04-044 Alternate name PGC 005341
Alternate names:
    MCG -1- 4- 44    UGCA     17    A   0123-06
Right ascension: 01h26m19.14s
Declination: -06 04' 26.0"


>Diego Rodriguez
>drodrig@globalmail.net
>M1 Group Madrid Spain
>
>
>>Re: [vsnet 1575] Re: (fwd) On SN1998dm (Howerton) - by Larry
>>
>>> 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?
>>
>>    Your finding is correct; most star chart plotting program seem to use
>>the original MCG coordinates.
>>
>>  Original MCG coordinates (precessed to J2000.0) and RC3 ones:
>>
>>012618.0 -060359 (2000.0) RC3_A0123-06 PGC5341 .SB.5*.
>>012619.0 -060426 (2000.0) CfA_A0123-0620 v=1968km/s Bmag=13.1
>>012619.1 -060425 (2000.0) M-01-04-044
>>
>>  GSC and USNO entries for this galaxy (detected in IRAS also):
>>
>>GSC4684.2075 012614.03 -060555.4 (2000.0) 11.11 0 N
>>GSC4684.1578 012614.46 -060538.0 (2000.0) 10.48 0 N
>>USNO0825.00327490 012614.037 -060555.43 (2000.0) 11.1 99.9
>>USNO0825.00327515 012614.466 -060538.01 (2000.0) 10.5 99.9
>>USNO0825.00327522 012614.546 -060536.88 (2000.0)  9.3  9.7
>>012613.8 -060543 (2000.0) IRAS01237-0621 0.475L 0.296L 0.725 2.171 -1%
>>012613.8 -060543 (2000.0) SSC01237-0621 0.475L 0.296L 0.725 2.171
>>012614.8 -060537 (2000.0) FSC01237-0621 0.130L 0.145L 0.683 2.001
>>
>>  Regarding the supernova itself, the reported position seems to be a few
>>arcsec off, as I posted earlier -- could someone confirm this astrometry?
>>
>>  There is a 15.5 mag star west to the SN.  So observers are requested
>>to avoid confusion and/or contamination of this foreground star.
>>
>>  GIF image kindly provided by S. Massaro is at
>>
>>  http://ftp.kusastro.kyoto-u.ac.jp/vsnet/SNe/sn1998dm/sn1998dm.gif
>>
>>Regards,
>>Taichi Kato
>>
>

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