GCN Circular 348
Subject
X-ray/GRB 1SAX J0835.9+5118, Optical Observation
Date
1999-05-29T06:58:57Z (25 years ago)
From
Holger Pedersen at Copenhagen U Obs <holger@astro.ku.dk>
H. Pedersen, J. Hjorth, B. L. Jensen (Copenhagen), H. Korhonen, and
M. I. Andersen (NOT) report:
We have conducted a second (cf. GCN 340) series of imaging using
the 2.56-m Nordic Optical Telescope. The StanCam instrument was used,
giving a field of 3' x 3', hence significantly smaller than the 3'
radius error circle (GCN 333).
Three 5-min R-band images were acquired on May 25.927 UT. The seeing
was 0.9" FWHM.
We find no evidence for variability between the two observing epochs.
Specifically, the sn-like configuration mentioned in GCN 340 does not
show any variability in support of its association with the high
energy event. The sum image from the two runs can be inspected at
http://www.astro.ku.dk/~holger/g/XRT990520/news.html
The new images do not cover the position of the radio source discovered
by Frail et al. (GCN 334).
For the optical counterpart to this latter source (cf. GCN 335, 336,
338, 341, 345) we have deduced the brightness at the epoch of our first
observing session, May 20.90 UT, finding R = 20.84 +- 0.05.