GCN Circular 21942
Subject
3.6m Devasthal Optical Telescope observations of GRB 170428A
Event
Date
2017-09-28T13:19:00Z (8 years ago)
From
Shashi Bhushan Pandey at ARIES, INDIA <shashi@aries.res.in>
S. B. Pandey (ARIES Nainital), Brajesh Kumar, G. C. Anupama (IIA Bangaluru)
and Kuntal Misra (ARIES Nainital) on behalf of a larger GRB collaboration
Short-duration GRB 170428A (Swift trigger =750298, Beardmore et al. GCN 21042)
was observed by the 3.6m Devasthal Optical Telescope (DOT) recently commissioned
by ARIES Nainital. The observations were carried out as a part of early science
run and characterizations. Observations were carried out just before twilight
using the 4Kx4K CCD optical imager, the first light instrument. Several R-band
exposures of 300-sec each were acquired in seeing conditions of around 1.1 arcsec
starting around UT 22:45:57 i.e. 13.5 hours after the burst.
In the stacked R-band frame of 3*300-sec, the candidate optical afterglow (Xu et al.
GCN 21048; Bolmer et al. GCN 21050) was clearly seen embedded within the host galaxy.
The photometry at the afterglow position measures a magnitude of 22.7+-0.2 mag
(calibrated with respect to nearby USNO stars). However, in the present data-set,
contamination with the probable host galaxy can not be ruled out in the estimated magnitude.
This is the first GRB afterglow observations with the 3.6m DOT and the full team of
staff members associated with the project are thankfully acknowledged to get this telescope
commissioned. We expect to contribute towards observations of time critical events in
near future assuming longitudinal advantage of Indian sub-continent using this facility.
The message may be cited.