GCN Circular 955
Subject
GRB010214, candidate optical afterglow
Date
2001-02-21T17:41:23Z (24 years ago)
From
Evert Rol at U.Amsterdam <evert@astro.uva.nl>
E. Rol, I. Salamanca, L. Kaper, P. Vreeswijk (University of
Amsterdam), P. Lacerda (Leiden Observatory), S. Hodgkin, P.
Tzanavaris (University of Cambridge), N. Tanvir (University of
Hertfordshire), report on behalf of a larger collaboration:
"We have observed the BeppoSAX error box of GRB010214 (Gandolfi, GCN
#932) with the 4.2m William Herschel Telescope (+ Prime Focus) and
with the 2.2m Isaac Newton Telescope (+ WFC) at La Palma, as follows:
Telescope Date Filter Exp.time Seeing Lim. mag.
(UT) (secs) (") (3 sigma)
=================================================================
WHT (+PF) 2001 Feb 15.26 R 2 x 225 0.84 ~23.5
INT (+WFC) 2001 Feb 17.25 R 2 x 900 1.2 ~24.2
(Note that in our calibration, the USNO star mentioned by Masetti et
al. (GCN #945) has a magnitude of R=18.4 instead of R=18.3.)
Within the refined NFI error box (Frontera et al., GCN #950), we
detect one object which faded from R = 22.9 to R = 24.1 (1 sigma error
about 0.2 mag) between the two observations.
The source seems to be extended, likely to be due to an underlying
galaxy. We consider this object to be a strong candidate for the optical
afterglow of GRB010214. The candidate is located at RA = 17:41:02.9
and Dec = 48:34:30 (J2000; error about 1 arcsec).
Another variable source is located just outside the refined NFI error
box, though within the initial NFI error box (Gandolfi, GCN #937),
with a position of RA = 17:41:04.6, Dec = 48:33:47 (J2000). This
source has faded from R = 23.1 to 24.0 (error of ~0.2 mag). The
infrared object mentioned by Di Paola et al. (GCN #939; see also
Antonelli, GCN #944) is clearly visible in our images (R~22.6 in the
WHT image). We measure two slightly different magnitudes (difference
of about 0.3), which might indicate a variable star.
Images and more information can be found on
http://www.astro.uva.nl/~evert/grb010214/
This message can be cited."