GRB 181010A
GCN Circular 23326
Subject
GROND afterglow detection of GRB 181010A
Date
2018-10-11T16:01:19Z (8 years ago)
From
Patricia Schady at Swift <p.schady@bath.ac.uk>
P. Schady (Uni. of Bath, UK) and J. Bolmer (MPE, Garching) report:
We observed the field of GRB 181010A (Swift trigger 866434; Melandri et al., GCN #23309) 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 were performed in rapid response mode, and started at 05:59 UT, 3 mins after the GRB trigger. They were performed at an average seeing of 1.4" and at an average airmass of 1.0.
We detect a new source at a position consistent with the X-ray and optical afterglow (Gorbovskoy et al., GCN #23310; Evans et al., GCN #23313; Emery, GCN #23317). Based on the first 3.3 min of total exposures in g'r'i'z' and 3 min in JHK, we measure the following preliminary AB magnitudes:
g' = 20.02 +/- 0.02 mag
r' = 19.33 +/- 0.01 mag
i' = 19.13 +/- 0.02 mag
z' = 18.56 +/- 0.01 mag
J = 17.78 +/- 0.03 mag
H = 17.02 +/- 0.03 mag
Given magnitudes are calibrated against PanSTARRS and 2MASS field stars and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.03 in the direction of the burst (Schlafly & Finkbeiner 2011).
We thank Markus Rabus for the excellend support from La Silla.
GCN Circular 23323
Subject
GRB 181010A: REM optical and NIR afterglow detection
Date
2018-10-11T11:06:56Z (8 years ago)
From
Paolo D'Avanzo at INAF-OAB <paolo.davanzo@brera.inaf.it>
P. D'Avanzo, S.Covino, D. Fugazza, A. Melandri (INAF-OAB), on behalf of the REM team, report:
We observed the optical counterpart of GRB 181010A (Melandri et al. GCN 23309; Gorbovskoy et al. GCN 23310; Martone et al. GCN 23311;
Troja et al. GCN 23312; Vielfaure et al. GCN 23315; Emery et al. GCN 23317; D'Avanzo et al. GCN 23319) with the REM 60cm robotic telescope
located at the ESO premise of La Silla (Chile). The observations were performed starting on 2018 October 10 at 05:56:52 UT (i.e. 61 seconds
after the burst) and were carried simultaneously in the g, r, i, z, and H bands.
The GRB afterglow is detected in the first set of optical and NIR images. From preliminary photometry we estimate the following magnitudes:
r = 18.2 +/- 0.2 (AB; calibrated against the Pan-STARRS catalogue)
H = 14.4 +/- 0.2 (Vega; calibrated against the 2MASS catalogue)
at a mean time of 4.1 minutes from the GRB time (Melandri et al. GCN 23309).
GCN Circular 23321
Subject
GRB 181010A: Swift-BAT refined analysis
Date
2018-10-10T21:12:55Z (8 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@milkyway.gsfc.nasa.gov>
A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (CPI),
H. A. Krimm (NSF/USRA), C. B. Markwardt (GSFC), A. Melandri (INAF-OAB),
D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 181010A (trigger #866434)
(Melandri, et al., GCN Circ. 23309). The BAT ground-calculated position is
RA, Dec = 52.574, -23.023 deg, which is
RA(J2000) = 03h 30m 17.7s
Dec(J2000) = -23d 01' 22.7"
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 85%.
The mask-weighted light curve shows several overlapping peaks starting
at ~T-5sec, peaking at ~T+8 sec, and returning to baseline at ~T+15 sec.
T90 (15-350 keV) is 16.4 +- 2.2 sec (estimated error including systematics).
The time-averaged spectrum from T-4.04 to T+15.21 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.52 +- 0.15. The fluence in the 15-150 keV band is 6.9 +- 0.7 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+7.43 sec in the 15-150 keV band
is 1.4 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence
level.
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/866434/BA/
GCN Circular 23320
Subject
GRB 181010A: Fermi GBM observation
Date
2018-10-10T19:34:51Z (8 years ago)
From
Peter Veres at UAH <veresp@gmail.com>
A. von Kienlin (MPE) reports on behalf of the Fermi GBM Team:
"At 05:55:59.39 UT on 10 October 2018, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 181010A (trigger 560843764 / 181010247),
which was also detected by the Swift/BAT (Melandri et al. 2018, GCN 23309).
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight at the GBM trigger time is 48.1
degrees.
The GBM light curve shows two structured pulses followed a weak tail with
an overall duration (T90) of about 60 s (50-300 keV). The time-averaged
spectrum
from T0-0.256s to T0+1.280s is best fit by a power law function with an
exponential
high-energy cutoff. The power law index is -0.8 +/- 0.2 and
the cutoff energy, parameterized as Epeak, is 280 +/- 80 keV.
The event fluence (10-1000 keV) in this time interval is
(6.13 +/- 0.98)E-07 erg/cm^2. The 1.024 sec peak photon flux measured
starting from T0-0.128 s in the 10-1000 keV band
is 3.35 +/- 0.29 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
GCN Circular 23319
Subject
GRB 181010A: ePESSTO NTT optical observations
Date
2018-10-10T18:48:11Z (8 years ago)
From
Paolo D'Avanzo at INAF-OAB <paolo.davanzo@brera.inaf.it>
T. Reynolds (Turku), S. Moran (Turku/NOT), P. D'Avanzo (INAF-OAB), D. B. Malesani (DAWN/NBI and DARK/NBI), M. De Pasquale (Istanbul Univ.),
S. Campana, A. Melandri (INAF-OAB), J. Harmanen, H. Kuncarayakti (Turku), R. Cartier (CTIO), M. Dennefeld (IAP), C. Inserra (Southampton),
E. Kankare (QUB), K. Maguire (QUB), S. J. Smartt (QUB), O. Yaron (Weizmann), D. R. Young (QUB), I. Manulis (Weizmann) report:
We observed the optical counterpart of GRB 181010A (Melandri et al. GCN 23309; Gorbovskoy et al. GCN 23310; Martone et al. GCN 23311;
Troja et al. GCN 23312; Vielfaure et al. GCN 23315; Emery et al. GCN 23317) under the extended Public ESO Spectroscopic Survey for Transient
Objects (ePESSTO; see Smartt et al. 2015, A&A, 579, 40; http://www.pessto.org <http://www.pessto.org/> ). The observations were performed on the ESO New Technology
Telescope at La Silla with the EFOSC2 instrument in imaging mode starting from 2018-10-10 at 08:37:50 UT (i.e. 2.7 hours from the burst).
The observations ended at 08:53:03 UT and were carried out with the R and i filters.
The optical afterglow is clearly detected in the R-band image. From preliminary photometry, we find a magnitude of R ~ 22.9 +/- 0.1
(Vega, calibrated against the USNOB1 catalogue). The afterglow is marginally detected in the i-band. From preliminary forced photometry
at the afterglow position, we derive a magnitude of i ~ 21.4 +/- 0.4 (AB, calibrated against the Pan-STARRS catalogue). These results,
compared to previous reports (e.g. Martone et al. GCN 23311; Troja et al. GCN 23312; Vielfaure et al. GCN 23315), suggest for a significant fading
of the optical afterglow flux.
GCN Circular 23317
Subject
GRB 181010A: Swift/UVOT Detection
Date
2018-10-10T12:55:25Z (8 years ago)
From
Sam Emery at MSSL-UCL <samuel.emery.15@ucl.ac.uk>
S.W.K. Emery (UCL-MSSL) and A. Melandri (INAF-OAB)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 181010A
96 s after the BAT trigger (Melandri et al., GCN Circ. 23309).
A source consistent with the XRT position
(Evans et al. GCN Circ. 23313)
is detected in the initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 03:30:16.89 = 52.57038 (deg.)
Dec (J2000) = -23:02:15.4 = -23.03761 (deg.)
with an estimated uncertainty of 0.49 arc sec. (radius, 90% confidence),
consistent with (MASTER-OAFA, Gorbovskoy et al., GCN Circ. 23310;
LCO Cerro Tololo, Martone et al., GCN Circ. 23311; RATIR, Troja et al., GCN Circ. 23312;
VLT/X-shooter, Vielfaure et al., GCN Circ. 23315)
Preliminary detections and 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white_FC 96 246 147 19.42 +/- 0.09
white 589 6359 247 >21.0
v 3867 5503 393 >19.4
b 564 6323 413 >20.9
u 309 6117 639 >20.6
uvw1 4277 5912 393 >20.1
uvm2 4072 5707 393 >20.7
uvw2 5098 5298 197 >20.5
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.03 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 23316
Subject
GRB 181010A: Swift-XRT refined Analysis
Date
2018-10-10T12:30:27Z (8 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U.
Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), S. J. LaPorte
(PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU) and A. Melandri
report on behalf of the Swift-XRT team:
We have analysed 7.3 ks of XRT data for GRB 181010A (Melandri et al.
GCN Circ. 23309), from 96 s to 17.1 ks after the BAT trigger. The data
comprise 77 s in Windowed Timing (WT) mode with the remainder in Photon
Counting (PC) mode. The enhanced XRT position for this burst was given
by Evans et al. (GCN Circ. 23313).
The light curve can be modelled with an initial power-law decay with an
index of alpha=0.741 (+/-0.021), followed by a break at T+11.9 ks to an
alpha of 3.6 (+4.4, -0.7).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.88 (+0.11, -0.10). The
best-fitting absorption column is 3.1 (+/-0.5) x 10^21 cm^-2, in
excess of the Galactic value of 1.9 x 10^20 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum is 4.0 x 10^-11 (5.6 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 3.1 (+/-0.5) x 10^21 cm^-2
Galactic foreground: 1.9 x 10^20 cm^-2
Excess significance: 10.7 sigma
Photon index: 1.88 (+0.11, -0.10)
If the light curve continues to decay with a power-law decay index of
3.6, the count rate at T+24 hours will be 1.8 x 10^-4 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 7.4 x
10^-15 (1.0 x 10^-14) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00866434.
This circular is an official product of the Swift-XRT team.
GCN Circular 23315
Subject
GRB 181010A: VLT/X-shooter redshift
Date
2018-10-10T11:49:03Z (8 years ago)
From
Jean Baptiste at Paris Observatory <jean.baptiste.vielfaure@gmail.com>
J-B. Vielfaure (CNRS - GEPI/Observatorie de Paris), J. Japelj (API, U.
Amsterdam), D. B. Malesani (DAWN/NBI and DARK/NBI), V. D'Elia (SSDC), J. P.
U. Fynbo (DAWN/NBI), N. R. Tanvir (Univ. Leicester), S. D. Vergani (CNRS -
GEPI/Observatorie de Paris), A. Rossi (INAF-OAS), P. Vreeswijk (Radboud
Univ. Nijmegen), L. Izzo (HETH/IAA-CSIC), D. A. Kann (HETH/IAA-CSIC), B.
Milvang-Jensen (DAWN/NBI), D. Xu (NAOC) and K. E. Heintz (Univ. of
Iceland), report on behalf of the Stargate collaboration:
We observed the optical counterpart of GRB 181010A (Melandri et al. GCN
23309; E. Gorbovskoy et al. 23310; R. Martone et al. 23311; E. Troja et al.
23312) with the ESO-VLT UT2 equipped with the X-shooter spectrograph. From
the acquisition image we measure a preliminary magnitude of 20.4 +/- 0.1
mag in the r-band, calibrated against local Pan-STARRS sources. Several
spectra with increasing exposure time were collected; in this analysis we
consider only one with 600s exposure obtained in a Rapid Response Mode at
06:18:24.9 UT (at the start of observation, 0.37 hr after the GRB).
A bright continuum is observed across the entire wavelength range covered
by X-shooter. Several absorption and emission features are detected, which
can be identified as due to H-alpha and [OIII]5007/4959 in emission at z =
1.39. At this same redshift we also detect AlII1854/1862, SiII1808, the
MgII doublet, and MgI in absorption. Fine-structure lines from FeII and
NiII are also detected at z = 1.39, which makes the redshift association
with the GRB secure. An intervening system at z = 0.67 with absorption
features due to the MgII doublet and MgI is also identified in the
spectrum.
We acknowledge the ESO observing staff at Paranal, in particular Jorge
Lillo-Box.
GCN Circular 23313
Subject
GRB 181010A: Enhanced Swift-XRT position
Date
2018-10-10T10:29:09Z (8 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester)
report on behalf of the Swift-XRT team.
Using 441 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 181010A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 52.57030, -23.03844 which is equivalent
to:
RA (J2000): 03h 30m 16.87s
Dec (J2000): -23d 02' 18.4"
with an uncertainty of 1.8 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).
This circular was automatically generated, and is an official product of the
Swift-XRT team.
GCN Circular 23312
Subject
GRB 181010A: RATIR Optical and NIR Afterglow Detection
Date
2018-10-10T08:02:49Z (8 years ago)
From
Eleonora Troja at GSFC <eleonora.troja@nasa.gov>
Eleonora Troja (GSFC), Alan M. Watson (UNAM), Nat Butler (ASU),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G.
Richer (UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC),
Josh Bloom (UCB), Antonino Cucchiara (UVI), Owen Littlejohns
(ASU), Enrico Ramirez-Ruiz (UCSC), Jesus Gonzalez (UNAM),
Carlos Rom��n-Zuniga (UNAM), Harvey Moseley (GSFC), John
Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki Toy (UMD)
report:
We observed the field of GRB 181010A (Melandri, et al., GCN 23309)
with the Reionization and Transients Infrared Camera (RATIR;
www.ratir.org) on the 1.5m Harold Johnson Telescope at the
Observatorio Astronomico Nacional on Sierra San Pedro Martir from
2018/10 10.25 to 2018/10 10.29 UTC (4.2 min to 1.10 hours after
the BAT trigger), obtaining a total of 0.50 hours exposure in the
r and i bands and 0.24 hours exposure in the Z, Y, J, and H bands.
At the position of the optical afterglow (Melandri, et al.,
GCN 23309; Gorbovskoy, et al., GCN 23310), in comparison with the
USNO-B1 and 2MASS catalogs, we obtain the following detections:
r 20.30 +/- 0.20
i 21.03 +/- 0.10
Z 20.67 +/- 0.24
Y 20.24 +/- 0.21
J 19.87 +/- 0.24
H 19.16 +/- 0.17
These magnitudes are in the AB system and are not corrected for
Galactic extinction in the direction of the GRB.
We thank the staff of the Observatorio Astronomico Nacional in
San Pedro Martir.
Further observations are on-going.
GCN Circular 23311
Subject
GRB 181010A: LCO Cerro Tololo observations
Date
2018-10-10T07:35:32Z (8 years ago)
From
Cristiano Guidorzi at Ferrara U,Italy <guidorzi@fe.infn.it>
R. Martone, C. Guidorzi (U. Ferrara), S. Kobayashi (LJMU), C.G. Mundell
(U. Bath), A. Gomboc (U. Nova Gorica), I.A. Steele (LJMU), A. Cucchiara,
D. Morris (U. of Virgin Islands) on behalf of a large collaboration report:
We automatically began observing Swift GRB 181010A (Melandri et al. GCN
23309) with one LCO 1-m unit at Cerro Tololo from October 10, 06:02:54
UT (corresponding to 7.1 minutes from the GRB trigger time) with the
SDSS r' filter. We clearly detect the optical counterpart reported by
Swift-UVOT with r'=19.98 +- 0.12 mag from a 3x120s exposure at a mid
time of 10.7 minutes post GRB, as calibrated against nearby Pan-STARRS
objects.
GCN Circular 23310
Subject
GRB 181010A: MASTER-Argentina OT detection
Date
2018-10-10T06:54:35Z (8 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov,
N.Tyurina, P.Balanutsa,A.Kuznetsov, V.V.Chazov, D. Vlasenko
Lomonosov Moscow State University, Sternberg Astronomical Institute
R. Podesta, F. Podesta, C. Lopez, C.Francile
Observatorio Astronomico Felix Aguilar (OAFA)
Hugo Levato
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias
D. Buckley,
South African Astronomical Observatory
A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory
O. Gres, N.M. Budnev, Yu.Ishmuhametova
Applied Physics Institute of Irkutsk State University
V. Yurkov, A. Gabovich, Yu. Sergienko
Blagoveschensk Educational State University, Blagoveschensk
MASTER-OAFA robotic telescope (MASTER-Net: http://observ.pereplet.ru,
Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in
Argentina (OAFA observatory of San Juan National University) was pointed
to the GRB181010.25 19 sec after notice time and 42 sec after trigger
time at 2018-10-10 05:56:33 UT. On our first (60s coadd exposure) coadd
set we found 1 optical transient within SWIFT error-box (ra=52.55
dec=-23.0344 r=0.05) brighter than 18.24.
T-Tmid Date Time Expt. Ra Dec
Mag
---------|---------------------|-------|-----------------|-----------------|-------
72 2018-10-10 05:56:33 60 ( 3h 30m 16.8s , -23d 2m 14.9s)
18.05
The 5-sigma upper limit has been about 18.7 mag
The message may be cited.
====================================================================
The galactic latitude b = -53 deg., longitude l = 215 deg.
The observations made on zenit distance = 15 deg.The moon ( 2 % bright
part) below the horizon (The altitude of the Moon is -50 deg. ).
The sun altitude is -45.7 deg.
The object can be observed till sunrise at 2018-10-10 10:03:45
.
THIS BLOCK FOR MASTER-Team USERS ONLY.
Link to GRB181010.25 page:
https://200.123.254.238:49004//master2/grb.php?not=2018-10-10+05%3A56%3A14&sat=SWIFT&gcrd=%2852.55d%2C-23.0344d%29&eb=0.05&trig=2018-10-10+05%3A55%3A51&n=GRB181010.25
Long transients in E.B.
https://200.123.254.238:49004//master2/trans.php?wh=transients.coord2000@%27%3C%2852.55d%2C-23.0344d%29%2C0.1d%3E%27%3A%3Ascircle+and+transients.datetime%3E%3D%272018-10-10+05%3A55%3A51%27&class=9&t2=SWIFT+GRB181010.25+optical+counterpart+candidate
Short transients in E.B.
https://200.123.254.238:49004//master2/trans3.php?wh=transients3.coord2000@%27%3C%2852.55d%2C-23.0344d%29%2C0.1d%3E%27%3A%3Ascircle+and+transients3.datetime%3E%3D%272018-10-10+05%3A55%3A51%27&class=-1&t2=SWIFT+GRB181010.25+optical+counterpart+candidate
Two tube transients in E.B.
https://200.123.254.238:49004//master2/trans2.php?wh=transients2.coord2000@%27%3C%2852.55d%2C-23.0344d%29%2C0.1d%3E%27%3A%3Ascircle+and+transients2.datetime%3E%3D%272018-10-10+05%3A55%3A51%27&class=0&t2=SWIFT+GRB181010.25+optical+counterpart+candidate
Undef. objects 1 image
https://200.123.254.238:49004//master2/aobj.php?wh=stars.coord2000@%27%3C%2852.55d%2C-23.0344d%29%2C0.1d%3E%27%3A%3Ascircle+and+stars.class=0+and+stars.status+and+stars.proc_id=626837&t2=SWIFT+GRB181010.25+1+image+optical+counterpart+candidate
The observation and reduction will continue.
This circular was generated automatically.
The message may be cited.
GCN Circular 23309
Subject
GRB 181010A: Swift detection of a burst with an optical counterpart
Date
2018-10-10T06:07:32Z (8 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@milkyway.gsfc.nasa.gov>
A. Melandri (INAF-OAB), S. D. Barthelmy (GSFC),
M. J. Moss (George Washington University), K. L. Page (U Leicester)
and B. Sbarufatti (PSU) report on behalf of the Neil Gehrels Swift
Observatory Team:
At 05:55:51 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 181010A (trigger=866434). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 52.557, -23.035, which is
RA(J2000) = 03h 30m 14s
Dec(J2000) = -23d 02' 06"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve shows multiple peaks
with a total duration of about 25 sec. The peak count rate
was ~2200 counts/sec (15-350 keV), at ~8 sec after the trigger.
The XRT began observing the field at 05:57:24.7 UT, 93.0 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 52.56984, -23.03721 which is equivalent
to:
RA(J2000) = 03h 30m 16.76s
Dec(J2000) = -23d 02' 14.0"
with an uncertainty of 3.6 arcseconds (radius, 90% containment). This
location is 43 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper.
A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (1.89 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 5.9
(+2.46/-2.18) x 10^21 cm^-2 (90% confidence).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 96 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 03:30:16.89 = 52.57036
DEC(J2000) = -23:02:15.4 = -23.03760
with a 90%-confidence error radius of about 0.78 arc sec. This position is 3.0
arc sec. from the center of the XRT error circle. The estimated magnitude is
19.37 with a 1-sigma error of about 0.16. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.03.
Burst Advocate for this burst is A. Melandri (andrea.melandri AT brera.inaf.it).
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)