GCN Circular 907
Subject
H band observation of GRB 001212
Date
2000-12-22T17:59:41Z (24 years ago)
From
Jochen Greiner at Astrophys.Inst. Potsdam,Germany <jgreiner@aip.de>
J. Greiner, G. Szokoly (both AIP, Potsdam), J. Eisloeffel, B. Stecklum,
S. Klose (all TLS, Tautenburg), Th. Stanke (MPIfR, Bonn), N. Lodieu,
M. McCaughrean (both AIP, Potsdam), A.J. Castro-Tirado (LAEFF-INTA, Madrid
and IAA-CSIC, Granada), report:
We have observed the error box of GRB 001212 (GCN #899) on Dec. 15, 2000
(2.5 days after the GRB) and Dec. 17, 2000 with the 3.5m telescope of the
German-Spanish Calar Alto Observatory. The observations were done with
the NIR-camera Omega-Prime in the H band. Two adjacent pointings were made
with the 6.5 arcmin FOV camera, covering about 90% of the error box
(see the image at http://www.aip.de/~jcg/grb001212.html). Conditions were
non-photometric during the first night.
Photometric calibration of the images was done based on the 2MASS magnitude
of object 2MASS 0649178+362151 having H = (14.45+-0.06) mag (and a USNO R-band
magnitude of 16.1 mag). A comparison of the two epochs of (summed) H-band
images of GRB 001212 reveals no object in the GRB error box which faded by
more than 0.2 mag down to H = 18.3 mag.
-----------------------------------------------------
Date (UT) exposure (min) seeing limiting
(Start) Poin1 Poin2 (arcsec) mag.
-----------------------------------------------------
Dec. 15.1744 32 32 3.0 H = 18.3
Dec. 17.8188 6 7 1.3 H = 18.4
-----------------------------------------------------
The object mentioned by Mohan et al. (GCN #900) which was reported by
Gizis (GCN #901) to have H = (14.603+-0.083) mag based on the April 1, 1998
2MASS scan, was measured with H = (14.45+-0.10) mag and H = (14.50+-0.10) mag
at the two epochs, thus being constant within our measurement errors.
We appreciate the availability of the 2MASS 2nd Incremental catalog at
IPAC/Caltech.