Bright Sn in NGC 3877
Bright Sn in NGC 3877
A bright supernova, 1998S, has been found on March 3 by Chinese astronomers
at Beijing Observatory.
1998S is located in NGC 3877 an UMa galaxy at R.A. = 11h46m06s,
Decl. = +47o29'.0. Magnitude at discovery was 15.2 and a day later
it was measured 13.5.
Spectrum with Keck I show this object to be a type II event.
The supernova is easily seen with an 8" telescope from suburban
skies: use medium to
high powers. The galaxy is close to M106, well placed in the evening
sky.
Recent magnitude estimates show the star at around magn 12. A prediscovery image shows
the sn at magn 16.0 on March 2.7. Use this 
chart to estimate visually the supernova (indicated by an X) and send
reports to Stefano Pesci
An image by Bill Beam from Alaska on March 26:
and a light curve with observations to March 25 from VSNet, ISN and IAUCs
Norwegian Astronomical Society - Variable Star Section
***** COMPARISON STARS FOR SUPERNOVA 1998S IN NGC 3877 *****
[Compiled by Bjorn H. Granslo (last update 1998 March 11)]
B.Granslo has prepared a finder and sequence chart for this supernova.
It covers a field of 35'x35' and shows stars down to magnitude 15
and is mainly based on the GSC and USNO catalogues. It can be
retrieved from the following URL:
Finder chart
Below follows a list of field and sequence stars located within ~20'
from SN 1998S in NGC 3877:
| IDENT. | STAR NAME | RA 2000 | DEC. 2000 | V-MAG. |
B-V | REF.NOTES |
|---|
| 1 |
HIP 57399 |
11h46m03.0s |
47°46'46" |
3.69 |
1.18 |
Sp.KOIII |
| 2 |
HIP 57349 |
11h45m31.0s |
47°40'03" |
8.06 |
0.62 |
Sp.G2V |
| 3 |
HIP 57385 |
11h45m55.5s |
47°32'51" |
10.00 |
0.78 |
H Sp.Ko |
| 4 |
TYC 3452-1157 |
11h47m12.9s |
47°47'15" |
10.04 |
0.6 |
T |
| 5 |
TYC 3452-1079 |
11h47m39.9s |
47°32'41" |
11.20: |
|
TI (b-r)=+0.5 |
| 6 |
TYC 3452-1149 |
11h45m44.9s |
47°47'42" |
11.8 |
|
TI |
| 7 |
GSC 3452-0905 |
11h47m09.0s |
47°23'34" |
11.9: |
|
G1 |
| 8 |
GSC 3452-1238 |
11h45m26.8s |
47°48'32" |
12.2: |
|
G2 (b-r)=+0.7 |
| x |
GSC 3452-1101 |
11h45m35.6s |
47°33'12" |
12.5: |
|
G2 (b-r)=+1.1 |
| y |
GSC 3452-1061 |
11h46m29.2s |
47°31'09" |
12.6: |
|
G2 (b-r)=+0.2 |
| A |
GSC 3452-1170 |
11h46m20.1s |
47°35'32" |
12.6: |
|
G2 (b-r)=-0.3 |
| B |
GSC 3452-1091 |
11h45m41.5s |
47°32'47" |
13.2: |
|
G2 (b-r)=+0.6 |
| C |
GSC 3452-0978 |
11h45m30.1s |
47°26'41" |
13.8: |
|
G2 (b-r)=+1.1 |
| D |
GSC 3452-0997 |
11h46m38.0s |
47°27'36" |
14.5: |
|
G1 |
| E |
GSC 3452-0977 |
11h45m34.8s |
47°26'49" |
15.0: |
|
G1 (b-r)=+1.6 |
Identifications are from TA E-Circular 1278 (capital letters) and
NAS.VSS (others). Positions are given to an accuracy of 0.1s in R.A.
and 1" in Decl. V-magnitudes followed by a colon (:) are uncertain.
Accurate photometry is currently available only for stars 1, 2 and 3.
Star 1 is Chi UMa. Star 5 appears to be double. References to positions
and magnitudes are H = Hipparcos Catalogue, T = Tycho Catalogue,
TI = Tycho Input Catalogue, G1 = Guide Star Catalogue, Ver. 1.1 [GSC]
(single entry), G2 = GSC (mean of two entries). Colour indices (b-r)
are based on the PPM USNO-A1.0 catalogue. The catalogues were accessed
via the VizieR service of CDS, and the compiler wish to thank CDS for
this service.