[vsnet-chat 1230] (fwd) MGC+01-04044 confusion (Rodriguez)

[Taichi Kato <tkato>]

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

From DRODRIG@santandersupernet.com Tue Sep  1 07:16 JST 1998
From: "Diego Rodriguez" <DRODRIG@santandersupernet.com>
Subject: RE: MGC+01-04044 confusion
Date: Tue, 1 Sep 1998 07:52:04 +0200


Hello Taichi.
I have concluded there is some incorrect information as to the exact
position
 of the galaxy MCG-01-04-044.

Information of  MGC+01-04-044 Alternate name = PGC 5072
Guide 6.0 and Real Sky

>> However, an examination of the software RealSky reveals a position of
approximately 1h 26m 14s, -6d 5m 44s for the galaxy.

Right ascension: 01h23m18.92s
Declination: +07 47' 38.4"
Remarks from the PGC (Principal Galaxy Catalog):PGC 005072
Galactic longitude: 136.525
Galactic latitude: -54.234
Supergalactic longitude: 306.229
Supergalactic latitude: -4.632
Total B magnitude: 15.040 .410
Heliocentric galaxy RV from neutral hydrogen: 2700.000 9.676 km/s
Galaxy RV relative to the Local Group: 2882.851 km/second
Galaxy RV relative to the GSR: 2783.800 km/second
Galaxy RV corrected for Virgo infall: 2726.574 km/second
Galaxy RV relative to the 3K background: 2392.303 km/sec
Major axis: 0.656.192 arcminutes
   Alternate names:
           MCG  1- 4- 44      CGCG 411- 42   VV      730

Comments from the MCG (Morphological Catalog of Galaxies):
Total magnitude: 15.2
Magnitude is accurate to 1 mag
Surface brightness (1=brightest, 6=dimmest): 1
Major axis,  outer part: 0.60 arcminutes
Minor axis,  outer part: 0.40 arcminutes
Surface brightness, 1st outer region (1=brightest, 6=dimmest): 3
Right ascension: 01h23m18.s
Declination: +07 47' 38"
Magnitude: 15.2
Surface brightness, inner part
   (1=very bright, 6=barely visible): 1
Surface brightness, 1st outer region
   (1=very bright, 6=barely visible): 3

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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