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For those interested in studying the new SN 1993J in M81,
I've made up a "finding chart" below listing all I could find
out about the stars nearby. It may be of use to some of you,
or it may not. Please feel free to contact me with questions
or comments. I will try to send an updated version of the
chart below with accurate Bessel UBVRI magnitudes as soon as
I can determine their values. If you can measure some yourself,
please let me know and I'll send the information on to others!
I've tried to find information on the stars not too far
from the position of the SN. Below I try to give an
impression of the field around the southern part of M81.
The size is about 30 arcmin across (that is, much larger
than any CCD field of view we're likely to use).
The "*" marks the location of the SN, and "." are to give an
idea of the extent of the bright part of M81.
N
--------------------------------------
| . G | I recommend that
| .... | you look at the chart
| ..... | given in "The Supernova
| .M81 F | Search Charts and
| ..... E | Handbook", by Thompson
| ... D | and Bryan.
| A |
| * | Also, you can check out
| C | AAVSO variable star
| B | chart 094769.
| |
| |
| |
E | | W
| |
| |
| |
| X |
| |
| W |
| Y |
| Z |
| |
| |
--------------------------------------
S
The three closest stars to the SN are (positions listed are
from the Hubble Guide Star Catalog)
star visual GSC "V" RA (2000.0) Dec (2000.0)
-------------------------------------------------------------
A 12.3 09 55 45.2 +69 01 45
B 11.9 11.4 09 55 41.5 +69 00 30
C 14.0 14.6 09 55 23.6 +69 00 49
where "visual" is from the chart in "The Supernova Search
Charts and Handbook" and GSC is the Hubble Guide Star Catalog.
Based on these GSC positions, I derive a position (2000.0) of
SN 1993J 09 55 25.0 +69 01 13
Other stars that might possibly be placed in the same field
of view as the SN are (positions again from Guide Star Catalog)
star visual GSC "V" RA (2000.0) Dec (2000.0)
------------------------------------------------------------
D 12.4 12.0 09 54 31.9 +69 01 26
E 13.0 12.3 09 54 19.0 +69 02 38
F 14.1 14.5 09 54 53.4 +69 03 48
For astrometric purposes, you might wish to use the nearby
SAO stars (positions listed are from the SAO catalog):
star SAO num RA (1950.0) Dec (1950.0) SAO "mv" spectral class
---------------------------------------------------------------------------
W 15026 09 52 56.000 +69 08 21.75 8.8 K
X 15018 09 50 57.538 +69 10 36.56 10.5
Y 15020 09 50 58.832 +69 08 17.56 8.7 F
Note that the SAO "mv" magnitudes and visual magnitudes listed on
the "Supernova Search Charts" don't agree very well.
Please let me know if I've made typographical errors, or if there's
something else I can do. I'll try to send out rough photometry of
the SN from Leuschner last night soon.
Michael Richmond
richmond@astro.princeton.edu
Return to the Powerful Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
