[vsnet-grb-info 6522] Radio Detection of SGR 0501+4516

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8130
SUBJECT: Radio Detection of SGR 0501+4516
DATE:    08/08/25 14:25:40 GMT
FROM:    Shri Kulkarni at Caltech  <srk at astro.caltech.edu>

S. R. Kulkarni and D. A. Frail report:
We undertook VLA observations of SGR 0501+4516 (GCN 8113)
on 2008 August 24 (starting at 0928 UT, 30 min duration) and
2008 August 25 (starting at 1054 UT, 1 hour duration) in the
8-GHz and 1.4 GHz bands.

No source was detected in the first epoch in the 8-GHz band
(75 microJy rms), consistent with the lack of detection
by WSRT (GCN 8125)  on 2008 August 23 (03.66 to 09.49 UT).

A very strong source is seen in the second epoch:
	3 +/- 0.1 mJy (8.46 GHz)
        14 +/- 0.8 mJy (1.43 GHz)
The spectral index is -1 between these two frequencies.

One may conclude that SGR 0501+4516 is waking up from
hibernation. Radio observations at other frequencies are
strongly encouraged (to constrain the spectrum). Searches
for radio pulsations can be expected to be highly productive.
Finally, should the source remain radio bright, proper motion
measurements via VLBI become feasible.