GRB 121212A
GCN Circular 14085
Subject
GRB 121212A: LOAO IzY Observation
Date
2012-12-14T15:44:35Z (13 years ago)
From
Minsung Jang at Seoul National U <rigel103@snu.ac.kr>
M. Jang, M. Im (SNU), and Y. Urata (NCU), on behalf of EAFON
We observed GRB 121212A in IzY-bands starting at UT 08:51:52, 2012-12-12,
~ 2 hrs after the BAT trigger (Grupe et al, GCN 14064),
using the 1.0m telescope at Mt.Lemmon in Arizona, U.S.
We do not detect the GRB afterglow in all bands at the position
of the Swift/UVOT detection (Kuin et al. 14069).
We estimate the 3-sigma limiting magnitude (AB system) of the afterglow
for each band,
I > 20.0 (T0+7900s)
z > 18.3 (T0+9370s)
Y > 17.7 (T0+8260s),
by calibrating it against USNO-B1 stars with I2 magnitudes
and 2MASS point sources without the galactic extinction correction.
We thank the LOAO operator, I. Baek, for performing the observation.
GCN Circular 14083
Subject
GRB 121212A: PdBI mm observations
Date
2012-12-14T08:43:04Z (13 years ago)
From
Alberto Castro-Tirado at Inst.de Astro. de Andalucia <ajct@iaa.es>
A. J. Castro-Tirado (IAA-CSIC Granada), M. Bremer and J.-M. Winters (IRAM
Grenoble), on behalf of a larger collaboration, report:
"We conducted mm observations towards GRB 121212A (Grupe et al. GCNC
14064, Mereghetti et al. GCNC 14065) starting at 10.5 hr post burst with
the PdBI at 90 GHz. At the position of the X-ray/optical afterglows
(Beardmore et al. GCNC 14066, Kuin et al. GCNC 14069), no emission is
detected down to 0.3 mJy (3 sigma limit)."
This message can be quoted.
GCN Circular 14082
Subject
GRB121212A: NOT optical imaging
Date
2012-12-14T06:48:13Z (13 years ago)
From
Steve Schulze at U of Iceland <sts30@hi.is>
S. Schulze (PUC, MCSS), D. Malesani (DARK/NBI), T. Pursimo, J.
Jessen-Hansen (NOT) and P. Jakobsson (U Iceland) report on behalf a larger
collaboration:
We observed the field of GRB 121212A, detected by Swift (Grupe et al., GCN
14064) and INTEGRAL (Mereghetti et al., GCN 14065), with ALFOSC mounted at
the NOT. Observations started at 03:07:39 UT on 14 December, i.e. 1.8412
days after the trigger. We obtained a series of four R-band images with an
individual exposure time of 300 s.
We detect an object inside the UVOT-refined XRT
(http://www.swift.ac.uk/xrt_positions/00541371/) at
RA (J2000): 11:51:10.22
Dec (J2000): +78:02:14.51
We measured an R-band brightness of 23.5 +/- 0.1 mag with respect to four
USNO B1.0 stars (R2 magnitude). We did not apply any correction for
foreground extinction. Our measurement is consistent with Pozanenko et al.
(GCN 14079) and confirms that the object first reported by Kuin et al.
(GCN 14069) is the optical afterglow of GRB 121212A.
GCN Circular 14079
Subject
GRB 121212A: Maidanak optical observations
Date
2012-12-13T20:46:21Z (13 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Pozanenko (IKI), A. Sergeev (Institute of Radio Astronomy of NASU),
A. Volnova (SAI MSU), O. Burhonov (UBAI), I. Molotov (KIAM) report on
behalf GRB follow-up collaboration:
We observed the field of Swift GRB 121212A (Grupe et al., GCN
14064) with AZT-22 telescope of Maidanak observatory starting on Dec. 12
(UT) 20:51:02 under mean seeing (FWHM) of about 1 arcsec. Totally we
obtained 6 images of 600 s exposure in R filter. At the position of the
OT of GRB 121212A (Kuin et al., GCN 14069; Perley and Horesh, GCN
14070; Elenin et al., GCN 14071) we marginally detected an extended
object. If it will be confirmed the object might be a host galaxy of GRB
121212A.
A preliminary photometry of the object:
T0+ Filter, Exposure, OT
(mid, d) (s)
0.60088 R 6x600 23.0 �� 0.35
is based on USNO-B1.0 nearby stars:
USNO-B1.0 1680-0064718 11:51:09.04 +78:00:39.9 R2 = 16.34
USNO-B1.0 1680-0064713 11:51:05.10 +78:02:00.1 R2 = 19.35
GCN Circular 14076
Subject
GRB 121212A: RAPTOR Limits During Gamma-Ray Emitting Interval
Date
2012-12-13T01:06:51Z (13 years ago)
From
James Wren at LANL <jwren@nis.lanl.gov>
J. Wren, W.T. Vestrand, P. Wozniak, and H. Davis,
of Los Alamos National Laboratory report:
The RAPTOR network of robotic optical telescopes made observations of Swift
trigger 541371 (Grupe, et al., GCN 14064). The burst location was within
the field of our wide-field monitor located near Los Alamos, NM USA, which
began a 10 s exposure of the location at 06:56:03.18 UT, 10.2 s before the
Swift trigger time and covering the initial few seconds of gamma-ray emission
as detected by the BAT (Barthelmy, et al., GCN 14068). The next 10 s exposure
begins at 06:56:23.58 UT, 10.2 s after the Swift trigger time and overlapping
the end stages of the gamma-ray emission. We do not detect the optical
counterpart detected by the UVOT (Kuin, et al., GCN 14069) and others. Our
3-sigma limiting magnitudes are R~10.1 based on comparison of our unfiltered
images to the Tycho-2 V-band catalog.
Our narrow-field instruments began a series of 10 s exposures at 06:58:08.59
UT, 115 s after the Swift trigger. These images also do not show the optical
counterpart to a limiting magnitude of R~16.4 based on comparison to the
USNO-B1 R-band.
GCN Circular 14074
Subject
GRB 121212A: PAIRITEL NIR Observations
Date
2012-12-12T22:17:33Z (13 years ago)
From
Adam Morgan at U.C. Berkeley <qmorgan@gmail.com>
A. N. Morgan (UC Berkeley) reports:
We observed the field of GRB 121212A (Grupe et al., GCN 14064) with
the 1.3m PAIRITEL located at Mt. Hopkins, Arizona. Observations began
at 2012-Dec-12 09h50m10s UT, ~2.9 hours after the Swift trigger. In
mosaics (effective exposure time of 1.96 h) taken simultaneously in
the J, H, and Ks filters, we do not detect any source at the afterglow
location (Kuin et al., GCN 14069; Perley and Horesh, GCN 14070; Elenin
et al., GCN 14071; Cenko, GCN 14072).
post burst
t_mid (hr) exp.(hr) filt U. Limit (3 sig).
4.79 1.96 J > 19.0
4.79 1.96 H > 17.9
4.79 1.96 Ks > 17.1
All magnitudes are given in the Vega system, calibrated to 2MASS. No
correction for Galactic extinction has been made to the above reported
values.
GCN Circular 14073
Subject
GRB 121212A: Swift-XRT refined Analysis
Date
2012-12-12T19:06:05Z (13 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), O.M.
Littlejohns (U. Leicester), V. Mangano (INAF-IASFPA), A. Melandri
(INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), J.A. Kennea (PSU), M.C. Stroh
(PSU), D.N. Burrows (PSU) and D. Grupe report on behalf of the
Swift-XRT team:
We have analysed 9.1 ks of XRT data for GRB 121212A (Grupe et al. GCN
Circ. 14064), from 81 s to 19.3 ks after the BAT trigger. The data
are entirely in Photon Counting (PC) mode. The enhanced XRT position
for this burst was given by Beardmore et al. (GCN. Circ 14066).
The late-time light curve (from T0+5.3 ks) can be modelled with a
power-law decay with a decay index of alpha=0.80 (+/-0.24).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.48 (+0.17, -0.16). The
best-fitting absorption column is 2.2 (+/-0.4) x 10^21 cm^-2, in
excess of the Galactic value of 3.7 x 10^20 cm^-2 (Kalberla et al.
2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum is 3.1 x 10^-11 (6.2 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 2.2 (+/-0.4) x 10^21 cm^-2
Galactic foreground: 3.7 x 10^20 cm^-2
Excess significance: 7.7 sigma
Photon index: 2.48 (+0.17, -0.16)
If the light curve continues to decay with a power-law decay index of
0.80, the count rate at T+24 hours will be 0.011 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.3 x
10^-13 (6.6 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00541371.
This circular is an official product of the Swift-XRT team.
GCN Circular 14072
Subject
GRB 121212A: P60 Observations
Date
2012-12-12T18:26:40Z (13 years ago)
From
S. Bradley Cenko at Caltech <cenko@srl.caltech.edu>
S. B. Cenko (UC Berkeley) reports on behalf of a larger collaboration:
We have imaged the field of the Swift (Grupe et al., GCN 14064) and
Integral (Mereghetti et al., GCN 14065) GRB121212A with the robotic
Palomar 60 inch telescope. Observations began at 08:06 UT on 12 December
2012 (~ 1.2 hours after the Swift trigger) and were obtained in the r',
i', and z' filters.
At the location of the UVOT (Kuin et al., GCN 14069) and Keck/LRIS (Perley
and Horesh, GCN 14070) afterglow, we identify a faint source in our r' and
i' images. Using several nearby USNO-B1 point sources for reference, we
measure a magnitude of R = 20.45 +/- 0.19 at this time.
GCN Circular 14071
Subject
GRB 121212A: optical observations in ISON-NM observatory
Date
2012-12-12T18:12:28Z (13 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
L. Elenin (KIAM), A. Pozanenko (IKI), A. Volnova (SAI MSU, IKI), V.
Savanevych (KNURE), A. Bryukhovetskiy (NSFCTC), I. Molotov (KIAM), report on
behalf of larger GRB follow-up collaboration:
We observed the field of the Swift GRB 121212A (Grupe et al., GCN 14064)
with 0.45-m telescope of ISON-NM observatory starting on Dec. 12 (UT)
06:58:31, i.e 138 s after burst trigger. We took several unfiltered
images of 30 s exposures. An automatic real-time pipeline did not detect
any new object. However after stacking all images we marginally detected the
source not visible in any filter of DSS2 in coordinates 11 51 10.40 +78 02
15.3 with uncertainty of 0.3 arcsec in both coordinates. The source is
consistent with enhanced XRT afterglow position (Beardmore et al. GCN
14066) and optical transient (Kuin et al. GCN 14069; Perley and Horesh
GCN 14070) . A preliminary photometry of co-added frames is based on
the USNO-B1.0 (R2) nearby stars is following:
UT start, Exposure, OT, UL (3 sigma)
06:58:31 30 n/d 18.3
06:58:31 3x30 n/d 18.7
06:58:31 10x30 n/d 19.4
06:58:31 40x30 20.7 +/- 0.4 20.5
GCN Circular 14070
Subject
GRB 121212A: Keck observations
Date
2012-12-12T17:24:46Z (13 years ago)
From
Daniel Perley at Caltech <dperley@astro.caltech.edu>
D. A. Perley and A. Horesh (Caltech) report:
We slewed to the position of GRB121212A (rupe et al., GCN 14064) with
the Keck I telescope (+LRIS) and acquired a series of exposures with the
slit guider beginning at 15:40 UT, 8.7 hours after the event.
We identified a source near the DSS limit consistent with the XRT
position, at coordinates (J2000) of:
RA = 11:51:10.43
Dec = +78:02:15.3
(+/- 1.5 arcsec)
This is consistent with the XRT and UVOT positions (Beardmore et al.,
GCN 14066; Kuin et al., GCN 14069).
The magnitude is approximately R~21 on the guider camera at this time.
A series of 600s spectroscopic exposures were then taken during
brightening morning twilight.
A provisional reduction of the (low S/N) spectrum shows a significant
flux across the spectral range, extending to at least 3500 Angstroms
with no break or strong absorption lines, suggesting z ~< 2 and
consistent with the detection in the UVOT u filter. Analysis is ongoing.
GCN Circular 14069
Subject
GRB121212A: Swift/UVOT Detection
Date
2012-12-12T17:14:59Z (13 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N.P.M. Kuin (MSSL-UCL) and D. Grupe (PSU) report on behalf
of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 121212A
72 s after the BAT trigger (Grupe et al., GCN Circ. 14064). A source
consistent with the enhanced XRT position (Beardmore et al. GCN Circ.
14066) is detected in the initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 11:51:10.30 = 177.79292 (deg.)
Dec (J2000) = +78:02:14.3 = 78.03730 (deg.)
with an estimated uncertainty of 0.62 arc sec. (radius, 90% confidence).
Preliminary detections and 3-sigma upper limits using the UVOT photometric
system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early
exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white 72 7133 824 21.23 +/- 0.17
v 615 6108 352 >20.3
b 540 13527 1160 >20.9
u 285 1138 285 20.25 +/- 0.25
w1 664 11960 1238 >20.8
m2 639 6313 216 >20.5
w2 763 5904 255 >20.9
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.07 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 14068
Subject
GRB 121212A: Swift-BAT refined analysis
Date
2012-12-12T13:47:49Z (13 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), D. Grupe (PSU),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), G. Sato (ISAS), M. Stamatikos (OSU),
J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
Using the data set from T-60 to T+243 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 121212A (trigger #541371)
(Grupe, et al., GCN Circ. 14064). The BAT ground-calculated position is
RA, Dec = 177.787, 78.052 deg, which is
RA(J2000) = 11h 51m 08.8s
Dec(J2000) = +78d 03' 05.4"
with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
The mask-weighted light curve shows a couple peaks starting at ~T-3 sec,
peaking at ~T+0 sec, and ending at ~T+16 sec. T90 (15-350 keV) is
6.8 +- 1.3 sec (estimated error including systematics).
The time-averaged spectrum from T+0.02 to T+7.84 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
2.65 +- 0.40. The fluence in the 15-150 keV band is 1.2 +- 0.3 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.02 sec in the 15-150 keV band
is 0.7 +- 0.1 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/541371/BA/
GCN Circular 14066
Subject
GRB 121212A: Enhanced Swift-XRT position
Date
2012-12-12T12:02:15Z (13 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester)
report on behalf of the Swift-XRT team.
Using 1934 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 121212A, 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 = 177.79152, +78.03739 which is equivalent
to:
RA (J2000): 11h 51m 9.96s
Dec (J2000): +78d 02' 14.6"
with an uncertainty of 1.7 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 14065
Subject
GRB 121212A: A long GRB detected by INTEGRAL
Date
2012-12-12T09:54:06Z (13 years ago)
From
Sandro Mereghetti at IASF/CNR <sandro@iasf-milano.inaf.it>
S.Mereghetti (IASF-Milano), C.Ferrigno, E.Bozzo, I.Vovk (ISDC, Versoix),
D.Gotz (CEA, Saclay), and J.Borkowski (CAMK, Torun) on behalf of the IBAS
Localization Team report:
a gamma ray burst lasting about 10 s has been detected by IBAS in the
IBIS/ISGRI data at 06:56:12 UT of December 12.
Its refined coordinates (J2000) are:
R.A.= 177.8217 deg
DEC.= 78.0257 deg
with an uncertainty of 2 arcmin (90% c.l.).
The burst has a peak flux of 0,4 counts/cm2/s (20-200 keV, 1-s integration
time) and a fluence in the same energy range of about 8e-8 erg/cm2.
This burst has also been detected by Swift (Grupe et al. GCN Circ.14064).
Due to the significance of the detection below the high confidence
threshold, only an Alert Packet of WEAK type was distributed by IBAS in
real time (Packet n. 6720).
A plot of the light curve has been posted at
http://ibas.iasf-milano.inaf.it/IBAS_Results.html
GCN Circular 14064
Subject
GRB 121212A: Swift detection of a burst
Date
2012-12-12T07:05:59Z (13 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
D. Grupe (PSU), W. H. Baumgartner (GSFC/UMBC),
C. Guidorzi (U Ferrara), H. A. Krimm (CRESST/GSFC/USRA),
C. B. Markwardt (NASA/GSFC), K. L. Page (U Leicester),
D. M. Palmer (LANL) and M. Stamatikos (OSU/NASA/GSFC) report on behalf
of the Swift Team:
At 06:56:13 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 121212A (trigger=541371). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 177.841, +78.034 which is
RA(J2000) = 11h 51m 22s
Dec(J2000) = +78d 02' 04"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a FRED-like
structure with a duration of about 20 sec. The peak count rate
was ~2300 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 06:57:21.7 UT, 68.4 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 177.78252, 78.03720 which is equivalent
to:
RA(J2000) = 11h 51m 07.80s
Dec(J2000) = +78d 02' 13.9"
with an uncertainty of 4.1 arcseconds (radius, 90% containment). This
location is 45 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 (3.67 x
10^20 cm^-2, Kalberla et al. 2005), with an excess column of 4.2
(+2.54/-2.19) x 10^21 cm^-2 (90% confidence).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 71 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 25% of
the BAT error circle. The typical 3-sigma upper limit has been about 19.6 mag.
The 8'x8' region for the list of sources generated on-board covers 100% of the
BAT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.07.
Burst Advocate for this burst is D. Grupe (dxg35 AT psu.edu).
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.)