GRB 140907A
GCN Circular 16818
Subject
GRB 140907A: Continued DCT Observations
Date
2014-09-13T15:49:21Z (11 years ago)
From
S. Bradley Cenko at NASA/GSFC <brad.cenko@nasa.gov>
S. B. Cenko, A. Cucchiara (NASA-GSFC), J. Capone, V. Toy (UMD), E. Troja, A. Kutyrev (NASA-GSFC), S. Veilleux, and S. Gezari (UMD) report on behalf of a larger collaboration:
We re-observed the field of the Swift GRB 140907A (Krimm et al., GCN 16788) with the Large Monolithic Imager on the 4.3m Discovery Channel Telescope (DCT). Observations were obtained in the r' filter beginning at 11:28 UT on 2014 Sep 10 (~ 2.8 d after the Swift trigger) for a total exposure time of 720 s.
Using nearby point sources from the APASS catalog for calibration, we measure a magnitude of r' = 22.79 +/- 0.07 mag for the optical afterglow (Xu et al., GCN 16789; Kuin et al., GCN 16791). Compared with our previous epoch of DCT imaging, we infer a corresponding power-law decay index of alpha = 1.2 +/- 0.1.
GCN Circular 16814
Subject
GRB 140907A: Mondy optical observations
Date
2014-09-11T16:53:02Z (11 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Volnova (IKI), E. Klunko (ISTP), M. Eselevich (ISTP), I. Korobtsev
(ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up
collaboration:
We observed the field of the Swift GRB 140907A (Krimm et al., GCN
16788) with with AZT-33IK telescope of Sayan observatory (Mondy). We
obtained several images on Sep., 08 and Sep. 9. Within enhanced XRT
error circle (Goadet al., GCN 16795) we clearly detect the afterglow
(Xu et al., GCN 16789; Kuin and Krimm, GCN 16791).
Preliminary photometry is following:
date UT start t-T0 Filter Exp. OT OT_err
(mid, days) (s)
2014-09-08 15:38:52 1.00888 R 82*60 21.26 0.08
2014-09-09 14:35:11 1.97786 R 120*60 22.50 0.20
The photometry is based on the same USNO-B1.0 stars which were used in
GCN 16809:
ID RA Dec R2
1366-0072961 03:12:42.62 +46:36:01.4 15.84
1365-0072251 03:12:34.50 +46:35:42.0 14.55
1365-0072223 03:12:30.14 +46:35:37.7 15.57
The light curve can be found in
http://grb.rssi.ru/GRB140907A/GRB14907A_lc1.png
GCN Circular 16810
Subject
GRB 140907A: 1.23m CAHA optical observations
Date
2014-09-10T00:32:37Z (11 years ago)
From
Javier Gorosabel at IAA-CSIC <jgu@iaa.es>
J. Ugarte (UPV-EHU), S. Perez-Hoyos (UPV-EHU), A. Sanchez-Lavega
(UPV-EHU), R. Hueso (UPV-EHU), J. Gorosabel (IAA-CSIC/UPV-EHU) report on
behalf of the BEGIRA project:
We observed the GRB 140907A (GCN 16788) optical afterglow (GCN 16789, GCN
16791, GCN 16792, GCN 16793, GCN 16797, GCN 16800, GCN 16802, GCN 16803,
GCN 16804, GCN 16806, GCN 16809) with the 1.23m CAHA telescope. The
observations were carried out in the R and I-bands on Sep 8.96168-9.21435
UT (30.96-37.05 hours post GRB). The optical afterglow is clearly detected
with a magnitude I(Vega)=21.4, calibrated against the USNO B1.0 catalog.
GCN Circular 16809
Subject
GRB 140907A: TShAO observations
Date
2014-09-09T20:54:38Z (11 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Volnova (IKI), A. Pozanenko (IKI), W. Mundrzyjewski (Fesenkov
Astrophysical Institute), V. Tereshenko (Fesenkov Astrophysical
Institute) report on behalf of larger GRB follow-up collaboration:
We observed the field of the Swift GRB 140907A (Krimm et al., GCN
16788)with Zeiss-1000 (East) telescope of Tien Shan Astronomical
Observatory starting on Sep. 07, (UT) 17:05. We took several images in
R-filter. Within enhanced XRT error circle (Goadet al., GCN 16795) we
clearly detect the afterglow(Xu et al., GCN 16789; Kuin and Krimm, GCN
16791).
Preliminary photometry of first and last exposures is following
Date UT start t-T0,d Exp,s Filter OT OT_err
(mid)
2014-09-07 17:33:41 0.06357 600 R 18.94 0.08
2014-09-07 23:22:46 0.30598 600 R 20.22 0.07
The photometry is based on nearby USNO-B1.0 stars, R2 magnitudes.
Preliminary light curve of the afterglow of GRB 140907A obtained between
(UT) 17:33:41 and 23:22:46 can be found in
http://grb.rssi.ru/GRB140907A/GRB14907A_lc.png .
Within the time interval ( 17:33:41 - 23:22:46 ) the LC might be
approximated by power law with a power law index ~-2 which could suggest
the jet-brake within this interval.
GCN Circular 16806
Subject
GRB 140907A: MASTER optical observations
Date
2014-09-09T13:03:53Z (11 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <gcncirc@observ.inetcomm.ru>
E. Gorbovskoy, V. Lipunov, M.Pruzhinskaya, V.Kornilov, D.Kuvshinov,
N.Tyurina, N.Shatskiy, P.Balanutsa, D.Zimnukhov, A.Kuznetsov, V.V.Chazov,
D.Denisenko, A.Sankovich
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University
V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov, A. Gabovich
Blagoveschensk Educational State University, Blagoveschensk
K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk
Irkutsk State University
V.Krushinski, I.Zalozhnih, A. Popov
Ural Federal University, Kourovka
A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik
Kislovodsk Solar Station of the Pulkovo Observatory
Hugo Levato and Carlos Saffe
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)
Claudio Mallamaci, Carlos Lopez and Federico Podest
Observatorio Astronomico Felix Aguilar (OAFA)
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru)
located in Blagoveschensk was pointed to the GRB140907A 6987 sec after
notice time and 7504 sec after trigger time at 2014-09-07 18:12:13 UT
directly after weather conditions became suitable. On our first (180s
exposure) set we found optical transient within Swift error-box (ra=03
12 34 dec=+46 36 18 r=0.050000) on coadditional images in two epoch.
The protometry results available at Table 1.
Table 1.
Date and Time start T_trig-Tmid Exptime Mag err.mag
2014-09-07 18:12:13.4 7809 540 19.0 0.2
2014-09-07 19:23:43.6 12547 1260 19.4 0.2
The approximate power law index (alpha) from 7000 to 13000 seconds after
the trigger is about 0.81 +- 0.1 (F ~ t^-alpha).
Another two MASTER-II robotic telescop located in Kislovodsk and Tunka
made upper limit observations only in earlier time due to weather
conditions and high zenith distance of object. MASTER II in Tunka was
pointed to the GRB140907A 1021 sec after trigger time at 2014-09-07
16:24:10 directly after weather conditions became suitable. On our first
(180s exposure) image we haven`t found optical transient up to 16m. MASTER
II in Kislovodsk starting observations GRB140907A 17 sec after notice
time and 77 sec after trigger time at 2014-09-07 16:08:25 using FERMI GBM
coordinates. However OT position was not covered by MASTER-II. The
telescope pointing by Swift trigger 22 sec after notice time and 540 after
trigger time at 2014-09-07 16:16:08. On first (110s exposure) image we
haven`t found optical transient up to 12.5 m. The zenith distance of
object z~85 d.
Our white (clear) band is well described by a parity 0.8R+0.2B (USNO B1).
GCN Circular 16804
Subject
GRB 140907A: Nishi-Harima NIR Observations
Date
2014-09-09T07:55:31Z (11 years ago)
From
Akira Arai at Nishi-Harima Astro. Obs/U of Hyogo <arai@nhao.jp>
J. Takahashi, A. Arai, S. Honda, Y. Takagi, K. Morihana (Univ. of Hyogo)
report on behalf of Nayuta team and OISTER collaboration:
We observed the field of GRB 140907A (H. A. Krimm et al., GCN 16788)
with Nishiharima Infrared Camera (NIC) attached to the Nayuta 2-m
telescope at the Nishi-Harima Astronomical Observatory.
The observations were started at 19:00 UT on 2014-09-07.
We detected the near-infrared afterglow in J, H and Ks bands.
Photometric results of our observations are shown below.
We used 2MASS 03123451+4635419, 03123283+4635411, and 03123016+4635375
as reference stars for photometry.
# MID-UT Tmid-T0 T-EXP J_mag H_mag Ks_mag
-----------------------------------------------------------------------
19:07:32 3.0 600 17.5 +/- 0.2 17.0 +/- 0.1 16.6 +/- 0.3
------------------------------------------------------------------------
Tmid-T0: Elapsed time after the burst (hours)
T-EXP: Total Exposure time (seconds)
GCN Circular 16803
Subject
GRB 140907A: MITSuME Akeno Optical Observation
Date
2014-09-09T07:25:07Z (11 years ago)
From
Taketoshi Yoshii at Tokyo Tech <yoshii.t.ac@m.titech.ac.jp>
Y. Tachibana, Y. Saito, T. Yoshii, H. Ohuchi, Y. Yano,
S. Kurita, Y. Ono, T. Fujiwara, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:
We observed the field of GRB 140907A (Krimm et al., GCN Circular #16788) with the
optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm
telescope of Akeno Observatory, Yamanashi, Japan.
The observation started on 2014-09-07 17:05:39 UT (~1 h after the burst).
We detected the previously reported optical afterglow (Xu et al., GCN Circular #16789, Kuin and Krimm, GCN Circular #16791, Kuroda et al., GCN Circular #16793) in the g',Rc and Ic band.
The measured magnitudes are listed below.
T0+[day] MID-UT T-EXP[sec] g' Rc Ic
------------------------------------------------------------------------------
0.04064 17:09:16 360 19.2+/-0.2 18.2+/-0.2 17.3+/-0.1
0.07348 18:07:29 300 >19.2 >18.3 >17.7
------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration.
GCN Circular 16802
Subject
GRB 140907A: Discovery Channel Telescope observations
Date
2014-09-09T03:26:20Z (11 years ago)
From
Antonino Cucchiara at NASA/GSFC <antonino.cucchiara@nasa.gov>
A. Cucchiara (NASA-GSFC),S.B. Cenko (NASA-GSFC), J. Capone (UMD),
V. Toy (UMD), E. Troja (NASA-GSFC), A. Kutyrev (NASA-GSFC), S. Veilleux
(UMD), and S. Gezari (UMD) report on behalf of a larger collaboration:
"On September 08.37UT (approximately 16.5h after the discovery) we observed
the optical counterpart of GRB 140907A (Krimm et al. GCN 16788, Xu et al.
GCN 16789, Kuin et al. GCN 16791) with the Large Monolithic Imager (LMI) on
the 4.3m Discovery Channel Telescope (DCT) at Happy Jack, AZ. We observed in
g', r', and i' bands for a total of 6, 6 and 4 minutes respectively.
Using a set of stars from the APASS catalogue we derived the following
magnitude for the afterglow:
g' = 21.54 +- 0.17
r' = 20.92 +- 0.15
i' = 20.42 +- 0.16
We thank the DCT staff, in particular S. Strosahl and H. Larson for
their support in performing these observations."
GCN Circular 16800
Subject
GRB 140907A: T100 observations
Date
2014-09-08T16:49:15Z (11 years ago)
From
Eda Sonbas at NASA/GSFC <edasonbas@gmail.com>
E. Sonbas (Adiyaman Univ.), U. Temiz, H. Avdan (Cukurova Univ.), T. Guver
(Istanbul Univ.), E. Gogus (Sabanci Univ.), S. Eryilmaz (TUG), K. Yakut
(Ege Univ.), H. Kirbiyik (TUG) report on behalf of a larger collaboration
We observed the field of Swift GRB 140907A (Krimm et al., GCN#16788) with
the 1.0 meter T100 telescope (Bakirlitepe, TUBITAK National Observatory,
Turkey), starting September, 7, 23:54:47 UT (~ 7.794 hours after the
trigger). Observations were carried out in the R filter. The afterglow is
clearly detected in 300 s in the R band images.
Using USNO-B1 star USNO-B1 1366-0072923 (R.A.=48.155, Dec=+46.614) in the
field, the magnitude of the OT was estimated as follows;
t-t0 (hr) exp.(s) filt mag err (+/-)
7.794 300 R 19.65 0.20
We are grateful to TUBITAK National Observatory for prompt scheduling the
observations and technical support.
GCN Circular 16799
Subject
GRB 140907A: Swift-BAT refined analysis
Date
2014-09-08T16:12:53Z (11 years ago)
From
Hans Krimm at NASA-GSFC <hans.a.krimm@nasa.gov>
T. Sakamoto (AGU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
M. Stamatikos (OSU), J. Tueller (GSFC), 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 140907A (trigger #611933)
(Krimm, et al., GCN Circ. 16788). The BAT ground-calculated position is
RA, Dec = 48.133, 46.596 deg which is
RA(J2000) = 03h 12m 31.9s
Dec(J2000) = +46d 35' 43.8"
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 65%.
The mask-weighted light curve shows a single peak with superimposed spikes,
running from approximately T-10 to T+40 sec. T90 (15-350 keV) is 79.2 +- 31.4 sec
(estimated error including systematics).
The time-averaged spectrum from T-91.2 to T+39.9 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.72 +- 0.07. The fluence in the 15-150 keV band is 4.3 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+17.47 sec in the 15-150 keV band
is 2.5 +- 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/611933/BA/
GCN Circular 16798
Subject
GRB 140907A: Fermi GBM Detection
Date
2014-09-08T15:32:05Z (11 years ago)
From
Binbin Zhang at UAH <binbin.zhang@uah.edu>
Bin-Bin Zhang (UAH) reports on behalf of the Fermi GBM Team:
"At 16:07:11.80 UT on 07 September 2014, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 140907A (trigger 431798834 / 140907672), which
was also detected by the Swift/BAT (Krimm et al 2014, GCN 16788)
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 16 degrees.
The GBM light curve consists of a single pulse with multiple peaks.
The total duration (T90) is about 35 +/- 10 s (50-300 keV).
The time-averaged spectrum from T0-12 s to T0+22 s is
best fit by a power law function with an exponential
high-energy cutoff. ��The power law index is -0.97 +/- 0.08 ��and
the cutoff energy, parameterized as Epeak, is 113 +/- 7 keV.
The event fluence (10-1000 keV) in this time interval is
(5.5 +/- 0.2)E-06 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+8.9 s in the 10-1000 keV band
is 4.2 +/- 0.3 ��ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
GCN Circular 16797
Subject
GRB 140907A: redshift from the 10.4m GTC telescope
Date
2014-09-08T08:01:07Z (11 years ago)
From
Alberto Castro-Tirado at Inst.de Astro. de Andalucia <ajct@iaa.es>
A.J. Castro-Tirado (IAA-CSIC/ISA-UMA), J. Gorosabel (IAA-CSIC/UPV-EHU) and
A. Garcia-Rodriguez (GTC-IAC), report on behalf of a larger collaboration:
We observed the optical afterglow of GRB 140907A (Krimm et al. GCN 16788;
Kuin et al. GCN 16791; Masi et al. GCN 16792, Kuroda et al. GCN 16793)
with the 10.4m GTC (+OSIRIS). Spectroscopic observations started at
05:29:33 UT (13.4 hours post GRB). Two 500s spectra were obtained with the
R1000B and R1000R grisms, covering the range between 3800 and 9900 A, at a
resolution of ~1000. A preliminary reduction based on archival calibration
lamps, reveals the Mg II doublet plus several Fe II lines at a common
redshift of z = 1.21, which we identify as the redshift of the GRB.
GCN Circular 16796
Subject
GRB 140907A: Swift-XRT refined Analysis
Date
2014-09-08T07:35:05Z (11 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), M.C. Stroh (PSU),
D.N. Burrows (PSU), J.A. Kennea (PSU), K.L. Page (U. Leicester), C.
Pagani (U. Leicester), A.P. Beardmore (U. Leicester), P. D'Avanzo
(INAF-OAB) and H.A. Krimm report on behalf of the Swift-XRT team:
We have analysed 8.8 ks of XRT data for GRB 140907A (Krimm et al. GCN
Circ. 16788), from 73 s to 40.5 ks after the BAT trigger. The data
comprise 89 s in Windowed Timing (WT) mode (the first 9 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Goad et al.
(GCN Circ. 16795).
The light curve can be modelled with an initial power-law decay with an
index of alpha=3.1 (+0.8, -0.7), followed by a break at T+119 s to an
alpha of 0.822 (+0.023, -0.025).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.01 (+0.14, -0.13). The
best-fitting absorption column is 3.8 (+0.7, -0.6) x 10^21 cm^-2, in
excess of the Galactic value of 3.1 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 3.9 x 10^-11 (6.0 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 3.8 (+0.7, -0.6) x 10^21 cm^-2
Galactic foreground: 3.1 x 10^21 cm^-2
Excess significance: 1.9 sigma
Photon index: 2.01 (+0.14, -0.13)
If the light curve continues to decay with a power-law decay index of
0.822, the count rate at T+24 hours will be 0.024 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 9.1 x
10^-13 (1.4 x 10^-12) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00611933.
This circular is an official product of the Swift-XRT team.
GCN Circular 16795
Subject
GRB 140907A: Enhanced Swift-XRT position
Date
2014-09-08T01:03:06Z (11 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester)
report on behalf of the Swift-XRT team.
Using 2873 s of XRT Photon Counting mode data and 7 UVOT
images for GRB 140907A, 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 = 48.14575, +46.60472 which is equivalent
to:
RA (J2000): 03h 12m 34.98s
Dec (J2000): +46d 36' 17.0"
with an uncertainty of 1.4 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 16794
Subject
GRB 140907A: MITSuME Ishigakijima Optical Observation
Date
2014-09-08T00:47:24Z (11 years ago)
From
Daisuke Kuroda at OAO/NAOJ <dikuroda@oao.nao.ac.jp>
D. Kuroda (OAO, NAOJ), H. Hanayama, T. Miyaji, J. Watanabe (IAO, NAOJ),
K. Yanagisawa (OAO, NAOJ), S.Nagayama (NAOJ), M. Yoshida (Hiroshima),
K. Ohta (Kyoto) and N. Kawai(Tokyo Tech)
report on behalf of the MITSuME and OISTER collaboration:
We observed the field of GRB 140907A (Krimm et al., GCNC 16788)
with the optical three color (g', Rc and Ic) CCD camera attached
to the Murikabushi 1m telescope of Ishigakijima Astronomical
Observatory.
The observation started on 2014-09-07 16:18:10 UT (~11 min after the burst).
We detected the previously reported afterglow (Xu et al., GCNC 16789;
Kuin and Krimm, GCNC 16791) in all the three bands.
Photometric results of the OT are listed below.
We used GSC 2.3 catalog for flux calibration.
#T0+[day] MID-UT T-EXP[sec] g' g'_err Rc Rc_err Ic Ic_err
--------------------------------------------------------------------------
0.01128 16:23:22 540.0 17.97 0.05 17.07 0.03 16.44 0.03
0.14407 19:34:36 540.0 19.73 0.12 19.36 0.11 18.48 0.11
--------------------------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]
GCN Circular 16793
Subject
GRB140907A: MITSuME Okayama Optical Observation
Date
2014-09-08T00:47:19Z (11 years ago)
From
Daisuke Kuroda at OAO/NAOJ <dikuroda@oao.nao.ac.jp>
D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (OAO, NAOJ),
S. Nagayama (NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto)
and N. Kawai(Tokyo Tech)
report on behalf of the MITSuME and OISTER collaboration:
We observed the field of GRB 140907A (Krimm et al., GCNC 16788)
with the optical three color (g', Rc and Ic) CCD camera attached
to the MITSuME 50cm telescope of Okayama Astrophysical Observatory.
The observation started on 2014-09-07 16:21:50 UT (~15 min after the burst).
We detected the previously reported afterglow (Xu et al., GCNC 16789;
Kuin and Krimm, GCNC 16791) in all the three bands.
Photometric results of the OT are listed below.
We used GSC 2.3 catalog for flux calibration.
#T0+[day] MID-UT T-EXP[sec] g' g'_err Rc Rc_err Ic Ic_err
-----------------------------------------------------------------------
0.01381 16:27:01 540.0 18.2 0.2 17.2 0.1 16.6 0.1
------------------------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]
GCN Circular 16792
Subject
GRB 140907A : Virtual Telescope optical observations
Date
2014-09-07T22:07:14Z (11 years ago)
From
Gianluca Masi at Bellatrix Astronomical Obs <gianluca@bellatrixobservatory.org>
G. Masi and P. L. Catalano, the Virtual Telescope Project - Italy, report:
We started observations of GRB 140907A (Krimm et al., GCN 16788) with the 17"
robotic unit part of the Virtual Telescope (Ceccano, Italy) at 21:46:00 UT.
An optical source is visible where described by D. Xu et al. (GCN 16789) in a
image coming from the sum of tfour, 300-seconds exposures, unfiltered. The
position of the source is RA: 03 12 35.00 Decl.: +46 36 17.6 (J2000.0, mean
residuals of 0.2") and the magnitude was estimated to be around 20.0, assuming R
mags for the reference stars from UCAC-4.
The message may be cited.
GCN Circular 16791
Subject
GRB140907A: Swift UVOT detection
Date
2014-09-07T20:08:13Z (11 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
NPM Kuin (UCL/MSSL), and H. A. Krimm (CRESST/GSFC/USRA)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 140907A
(Krimm et al., GCN Circ. No. 16788) 107 seconds after the trigger.
There is a candidate afterglow in the rapidly available 2.7'x2.7'
sub-image at
RA(J2000) = 03:12:34.98 = 48.14575
DEC(J2000) = +46:36:17.5 = 46.60486
with a 90%-confidence error radius of about 0.75 arc sec, consistent
with the optical position from Xu et al. (GCN.Circ.No <http://gcn.circ.no/>.
16789).
Preliminary magnitudes observed in the initial images using the UVOT
photomatric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373)
are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white 107 257 150 16.66 +/- 0.04
u 321 534 213 16.61 +/- 0.06
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.29 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 16789
Subject
GRB 140907A : Optical observations from Nanshan
Date
2014-09-07T18:03:54Z (11 years ago)
From
Dong Xu at DARK/NBI <dong.dark@gmail.com>
D. Xu (DARK/NBI), X. Gao (Urumqi No.1 Senior High School, Xinjiang),
G.-J. Feng, A. Esamdin, L. Ma (XAO), Z.-J. Xu (Nanjing Putian
Telecommunications Co. Ltd., Jiangsu) report:
We observed the field of GRB 140907A (Krimm et al., GCN 16788) using
the 35cm robotic telescope and the 1m optical telescope located at
Nanshan, Xinjiang, China. The observations started at 16:18:42 UT on
2014-09-07 at the 35cm telescope without any filter, and 16:34:28 UT
at the 1m telescope in the R filter.
The afterglow is well detected in our images at coordinates
R.A. (J2000) = 03:12:34.98
Dec. (J2000) = +46:36:17.2
Error radius: ~ 0.7 arcsec
which is fully consistent with the UVOT position. Generally, the
afterglow has been decaying, and follows are the preliminary
measurements from the 35cm telescope:
Mid-Time Mag
2014/09/07.68001 16.7
2014/09/07.68083 16.7
2014/09/07.68164 16.7
2014/09/07.68244 16.9
2014/09/07.68325 17.0
2014/09/07.68405 17.1
2014/09/07.68485 17.0
2014/09/07.68565 16.9
2014/09/07.68646 17.2
with a typical error of 0.2 magnitude, calibrated with the R-band
catalog of NET CMC-14.
Observations are ongoing.
GCN Circular 16788
Subject
GRB 140907A: Swift detection of a burst with an optical counterpart
Date
2014-09-07T16:34:45Z (11 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
H. A. Krimm (CRESST/GSFC/USRA), V. D'Elia (ASDC), C. Gronwall (PSU),
L. Izzo (URoma/ICRA), K. L. Page (U Leicester), D. M. Palmer (LANL)
and T. N. Ukwatta (LANL) report on behalf of the Swift Team:
At 16:07:08 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 140907A (trigger=611933). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 48.147, +46.595 which is
RA(J2000) = 03h 12m 35s
Dec(J2000) = +46d 35' 42"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a single spiky peak
structure with a duration of about 40 sec. The peak count rate
was ~3100 counts/sec (15-350 keV), at ~15 sec after the trigger.
The XRT began observing the field at 16:08:32.3 UT, 83.6 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source with an enhanced position: RA, Dec
48.1461, 46.6051 which is equivalent to:
RA(J2000) = 03h 12m 35.06s
Dec(J2000) = +46d 36' 18.2"
with an uncertainty of 2.2 arcseconds (radius, 90% containment). This
location is 36 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 consistent with the Galactic value of 3.13
x 10^21 cm^-2 (Willingale et al. 2013).
The initial flux in the 2.5 s image was 5.46e-10 erg cm^-2 s^-1 (0.2-10
keV).
Automated analysis of the UVOT data products is not available, however
there appears to be a new bright optical source at the XRT position in
the prompt finding chart exposure. More information will be available
when the full dataset is received.
Burst Advocate for this burst is H. A. Krimm (hans.krimm AT nasa.gov).
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.)