Die AAVSO meldet in AAVSO Alert Notice 363 die Supernova SN 2007sr in NGC 4038. Die Helligkeit beträgt 12,9 mag. Die Antennengalaxie befindet sich im Sternbild Rabe und kann bei CS am Morgenhimmel beobachtet werden. Hier ist zur Zeit ewige Inversionssuppe, wahrscheinlich Strafwetter für einen neuen 12"-Dobson.
<i>Further to CBETs #1172 (Drake et al.; Daniel W.E. Green,
editor), #1173 (Naito et al.), and #1174 (Umbriaco et
al.), the optical transient in NGC 4038 discussed in
AAVSO Special Notice #84 has been identified as a
supernova of Type Ia, and given the name SN 2007sr.
Umbriaco et al. have determined the supernova is a few
days past maximum light based upon spectroscopic
template fitting.
The supernova was at magnitude 12.9 on 2007 December
18.53 UT (JD 2454453.03; Drake et al., CBET #1172).
Subsequent multiband photometry confirms this
detection: B=13.20, V=12.85, R=12.80 (all accurate to
+/- 0.05 magnitudes) on Dec 19.42 (JD 2454453.92;
Guido & Sostero, CBET #1172); mag=12.9 on Dec 19.52
(JD 2454454.02; Li, CBET #1172); B=13.42, V=12.86
on Dec 19.8 (JD 2454454.3; Naito et al., CBET #1173);
B=12.83, V=13.03, R=12.99 on Dec 20.47 (JD
2454454.97; Nicholson, BAAVSS-Alert).
Supernova 2007sr is located at the following coordinates:
RA: 12:01:52.80 , Dec: -18:58:21.7 (J2000)
A comparison star sequence for this supernova has now been added
to VSP, and charts of the field may be plotted online:
http://www.aavso.org/observing/charts/vsp/
It is advisable to check the "Use DSS Image" option so that
NGC 4038-4039 is included on the chart.
Please submit observations to the AAVSO with the name
"SN 2007SR" (AAVSO 1156-18C).
Good observing,
Matthew Templeton
Staff Astronomer, AAVSO
</i>
