GCN Circular 23798
Subject
GRB 190114C: Optical follow-up from HCT
Date
2019-01-27T11:12:34Z (5 years ago)
From
Brajesh Kumar at Indian Inst. of Astrophysics <brajesh.kumar@iiap.res.in>
Avinash Singh (IIA), Brajesh Kumar (IIA), D. K. Sahu (IIA), G. C.
Anupama (IIA), S. B. Pandey (ARIES) and Varun Bhalerao (IITB)
We followed-up the optical afterglow of GRB 190114C (Gropp et al., GCN
23688) with the 2-m Himalayan Chandra Telescope (HCT)
located at the Indian Astronomical Observatory, Hanle, India. The
observations were carried out in the Bessell R-band on
2019-01-24 15:02:44.59 UT (MJD 58507.627). The OT candidate (Lipunov et
al., GCN 23693; Selsing et al., GCN 23695; Bolmer
et al., GCN 23702; D'Avanzo et al., GCN 23729; Kim et al., GCN 23732,
23734; Kumar et al., GCN 23733, Kumar et al., GCN 23742,
Mazaeva et al., GCN 23746, Ragosta et al., GCN 23748, Watson et al., GCN
23749, 23751) is detected in a stacked R-band image
comprising of 4 images, each with an exposure of 300s. The magnitude,
calibrated using the magnitudes of field stars from the
USNO-B1.0 catalogue is estimated as 21.38+/-0.16 including host
contamination.
We corrected the host contamination using the magnitudes reported for
the source and source + galaxy by Mazaeva et al., GCN 23787.
The GRB OT magnitude after correction for the host galaxy is:
UT-mid Delta T(d) JD Exposure
Mag(AB)
---------------------- ------------ ----------- -------------
---------------
2019-01-24 15:02:44.59 9.754 2458508.127 1200s (4X300)
21.68 +/- 0.16
Using the reported magnitudes of GRB 190114C spanning almost 10 days in
the SDSS-r and Bessell-R band filters, we estimated that
the source flux (F_lambda) is declining with a power law exponent of
0.77+/-0.05, in agreement with the values inferred earlier
(Kumar et al. GCN 23733, Dado S. & Dar A. GCN 23735).
We thank the observing staff at IAO and CREST for their support during
the observations.