GRB 191016A
GCN Circular 26176
Subject
GRB191016A GROND observations
Date
2019-11-05T15:45:33Z (6 years ago)
From
Patricia Schady at Swift <p.schady@bath.ac.uk>
P. Schady (Univ. of Bath) and J. Bolmer (MPE Garching) report:
We observed the field of GRB 161019A (Swift trigger 929744; Gropp et al., GCN #26008) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla Observatory (Chile).
Observations started at 04:19 UT on 2019-10-16, 10 min after the GRB trigger. They were performed at an average seeing of 1.7" and at an average airmass of 1.7.
We detect a bright point source in all optical and near-infrared filters consistent with the reported optical afterglow position (Watson et al., GCN #26010; Siegel et al., GCN #26024). Based on the first 3.3 min of total exposures in g'r'i'z'JHK, we estimate preliminary AB magnitudes of
g' = 16.81 +/- 0.03
r' = 16.33 +/- 0.03
i' = 15.84 +/- 0.04
z' = 15.51 +/- 0.04
J = 15.28 +/- 0.05
H = 14.80 +/- 0.05
K = 14.83 +/- 0.08
Given magnitudes are calibrated against SDSS and 2MASS field stars and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.09 in the direction of the burst (Schlafly & Finkbeiner 2011).
We acknowledge the excellent support provided by the telescope operator at La Silla.
GCN Circular 26028
Subject
GRB 191016A: REM optical observations
Date
2019-10-18T13:44:05Z (6 years ago)
From
Andrea Melandri at INAF-OAB <andrea.melandri@inaf.it>
A. Melandri, S.Covino, D. Fugazza, P. D���Avanzo (INAF/OAB), on behalf of the REM team, report:
We observed the field of GRB191016A (Gropp et al. GCN 26008) with the REM 60cm robotic telescope located at the ESO premise of La Silla (Chile). The observations were performed starting from about 6 min after the event and were carried in the g, r, i, z bands.
The optical counterpart (Watson et al. GCN 26010; Zheng & Filippenko GCN 26011; Watson et al. GCN 26015; Hu et al. GCN 26017; Kim et al. 26018; Toma et al. GCN 26019; Siegel & Gropp GCN 26024) is detected in the optical bands. A preliminary photometry gives:
r = 16.1 +- 0.2 at 13 min from the GRB time.
Magnitudes are calibrated against the APASS catalogue.
GCN Circular 26026
Subject
GRB 191016A: Swift-XRT afterglow detection
Date
2019-10-18T00:12:22Z (6 years ago)
From
Boris Sbarufatti at PSU <bxs60@psu.edu>
K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), M. Perri
(ASDC), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), B. Sbarufatti (PSU),
D.N. Burrows (PSU), J. D. Gropp (PSU) and P.A. Evans (U. Leicester)
report on behalf of the Swift-XRT team:
Swift-XRT has performed follow-up observations of the
Swift/BAT-detected burst GRB 191016A (WeiKang Zheng et al. GCN Circ.
26012), collecting 4.2 ks of Photon Counting (PC) mode data between
T0+45.0 ks and T0+56.9 ks.
An uncatalogued X-ray source is detected consistent with being within
296 arcsec of the Swift/BAT position and is above the RASS limit, and
is therefore likely the GRB afterglow. Using 3470 s of PC mode data and
3 UVOT images, we find an enhanced XRT position (using the XRT-UVOT
alignment and matching UVOT field sources to the USNO-B1 catalogue):
RA, Dec = 30.26933, +24.50988 which is equivalent to:
RA (J2000): 02h 01m 04.64s
Dec(J2000): +24d 30' 35.6"
with an uncertainty of 1.9 arcsec (radius, 90% confidence). This
position is 93 arcsec from the Swift/BAT position.
The light curve can be modelled with a power-law decay with a decay
index of alpha=1.8 (+1.5, -0.5).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.9 (+0.5, -0.4). The
best-fitting absorption column is 1.4 (+1.7, -0.4) x 10^21 cm^-2,
consistent with the Galactic value of 1.0 x 10^21 cm^-2 (Willingale et
al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux
conversion factor deduced from this spectrum is 3.4 x 10^-11 (4.3 x
10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 1.4 (+1.7, -0.4) x 10^21 cm^-2
Galactic foreground: 1.0 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index: 1.9 (+0.5, -0.4)
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00929744.
The results of the full analysis of the XRT observations are available
at https://www.swift.ac.uk/ToO_GRBs/00929744.
This circular is an official product of the Swift-XRT team.
GCN Circular 26024
Subject
GRB 191016A: Swift/UVOT Detection
Date
2019-10-17T23:13:53Z (6 years ago)
From
Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>
M. H. Siegel and J. D. Gropp (PSU)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 191016A
45 ks after the BAT trigger (Gropp et al., GCN Circ. 26008