GRB 070419, GRB 070419A
GCN Circular 6486
Subject
GRB 070419A, deep LBT photometry and possible supernova detection
Date
2007-06-04T18:36:29Z (19 years ago)
From
Peter Garnavich at U of Notre Dame <pgarnavi@nd.edu>
J. Hill (LBTO/UAz), P. Garnavich (Notre Dame), O. Kuhn (LBTO/UAz),
N. Bouche, P. Buschkamp (MPE), X. Fan, (U Ariz), X. Dai, J. Prieto,
K. Z. Stanek (Ohio State), P. Milne, J. Bechtold (U Ariz),
R. M. Wagner (LBTO/OSU), J. Rhoads (Ariz State) report:
The Large Binocular Telescope (LBT) continued to image the position of the
GRB 070419A afterglow (Stamatikos et al, GCN 6302; Chornock et al. GCN 6304;
Garnavich et al. GCN 6406) with the LBC-blue CCD camera
(http//lbc.mporzio.astro.it) and 8.4-m SX mirror. Data were obtained
2007 May 10.18 (UT) and May 20.22 (UT) which are 20.8 and 30.8
days after the burst. Using the calibration assumed by Garnavich et al.
(GCN 6406), we estimate the brightness of the source at the
position of the afterglow using point-spread-function fitting
photometry as follows:
UT Date Age (days) Exposures Seeing r mag Error
-----------------------------------------------------------
Apr 23.15 3.7 10x200s 1.2" 24.75 0.18 (GCN 6406)
May 10.18 20.8 25x200s 0.96" 25.29 0.05
May 20.22 30.8 15x200s 0.73" 25.71 0.13
The decay between 4 days (LBT observation from GCN 6406) and 20 days
after the burst is very slow and corresponds to a power-law index of
0.3. This could indicate host galaxy contamination, but the
images remain unresolved. Extrapolating the decline to 30 days
post-burst predicts the afterglow should be 30% brighter than
the actual observed magnitude. This increased fading rate is
inconsistent with a host galaxy dominating the flux and
suggests light from a GRB progenitor supernova may be powering
the late-time light curve.
The Sloan-r filter has an effective wavelength of 623 nm which
maps to a rest-frame UV wavelength near 316 nm at a redshift
of 0.97 (Cenko et al. GCN 6322). The U-band light curve
of SN 1998bw peaked 13 to 15 days after GRB 980425 (Galama
et al. 1998, Nature, 395, 670) and possibly earlier at short
wavelengths. Some supernovae associated with GRB such as
SN 2001dh/011121 (Garnavich et al. 2003, ApJ, 582, 924) and
2006aj/060218 (Modjaz et al. 2006, ApJ, 645, 21) have peaked
earlier than SN 1998bw, so the decay seen at 16 rest-frame days
is consistent with a supernova interpretation.
Extrapolating the spectrum of SN 1998bw near maximum (Patat et al.
2001, ApJ, 555, 900) out to UV wavelengths, we estimate a peak
brightness of R=25.4 when viewed at z=0.97, which is also consistent
with the LBT observations.
A plot of the light curve can be found at:
http://www.nd.edu/~pgarnavi/grb070419a/grb070419a_lc.jpg
The LBT is an international collaboration among institutions in the
United States, Italy and Germany. The LBT Corporation partners are:
* The University of Arizona on behalf of the Arizona university system
* Istituto Nazionale di Astrofisica, Italy
* LBT Beteiligungsgesellschaft, Germany, representing the Max Planck
Society, the Astrophysical Institute Potsdam, and Heidelberg University
* The Ohio State University
* The Research Corporation, on behalf of The University of Notre Dame,
University of Minnesota and University of Virginia
This message may be cited
GCN Circular 6407
Subject
GRB070419A: optical observations
Date
2007-05-13T20:24:58Z (19 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Pozanenko (IKI), A. Shulga, A. Volnova (SAI MSU), B. Hafizov, I.
Asfandiyarov, M. Ibrahimov (MAO) on behalf of larger GRB follow up
collaboration report:
We observed optical afterglow of GRB070419A (Stamatikos et al, GCN 6302;
Chornock et al. GCN 6304) with 1.5m telescope of Maidanak observatory
(MAO). Several exposures in R-band in seeing ~1 arcsec were obtained on
Apr. 17 between (UT) 15:20 - 16:25. In a combined image the source at
(J2000) RA= 12 10 58.83 DEC= +39 55 34.06 with an error in both coordinates
of 0.15" is compatible with the coordinates of Chornock et al. (GCN 6304)
and Garnavich et al. (GCN 6406).
A photometry of the afterglow using USNO-A2.0 stars is following:
T0+ , Exposure, R_mag
0.245 d 11x300 s 22.4 +/- 0.3
Our observation is compatible with global power law decay index 0.9
(Garnavich et al. GCN 6406) suggesting no host galaxy contribution in epoch
of our observation.
The combined image can be found at
http://grb.rssi.ru/GRB070419A/GRB070419A_AZT22_R.jpg
This message may be cited.
GCN Circular 6406
Subject
GRB 070419A, Deep LBT photometry
Date
2007-05-10T22:17:25Z (19 years ago)
From
Peter Garnavich at U of Notre Dame <pgarnavi@nd.edu>
P. Garnavich (Notre Dame), X. Fan, (U Ariz), X. Dai, J. Prieto,
K. Z. Stanek (Ohio State), J. Hill (LBTO/UAz), J. Bechtold (U Ariz),
R. M. Wagner (LBTO/OSU), J. Rhoads (Ariz State) report:
The Large Binocular Telescope (LBT) imaged the position of the GRB 070419A
afterglow (Stamatikos et al, GCN 6302; Chornock et al. GCN 6304) with the
LBC-blue CCD camera (http//lbc.mporzio.astro.it) and 8.4-m SX mirror on
2007 April 23.15 (UT). Ten dithered, 200 second exposures were obtained
with the Sloan-r filter in 1.2" seeing. The combined image shows a faint
source at J2000 12:10:58.80 39:55:33.71 +/-0.2 arcsec which is coincident
with the Chornock et al. coordinates.
Assuming the star at RA = 182.73852, DEC = 39.93033 J2000 has a Sloan r
MODEL magnitude of 20.394 mag (Swan et al. GCN 6339; Cool et al. GCN
6318), we find the source at the position of the afterglow to be
r=24.75 +/- 0.18 mag at 3.7 days after the burst.
Observations less than an hour after the burst by Smith et al. (GCN 6315)
and Swan et al. (GCN 6339) compared with our photometry imply a power-law
decay index of 0.9+/-0.1 over nearly 4 days. This is consistent with the
initial decline index of 1.1 (Swan et al. GCN 6339) and suggests that
either no break in the light curve had occurred or the host galaxy is
contributing to the measured LBT flux.
The LBT image can be found at:
http://www.nd.edu/~pgarnavi/grb070419a/grb070419a_LBT.jpg
The LBT is an international collaboration among institutions in the
United States, Italy and Germany. The LBT Corporation partners are:
* The University of Arizona on behalf of the Arizona university system
* Istituto Nazionale di Astrofisica, Italy
* LBT Beteiligungsgesellschaft, Germany, representing the Max Planck
Society, the Astrophysical Institute Potsdam, and Heidelberg University
* The Ohio State University
* The Research Corporation, on behalf of The University of Notre Dame,
University of Minnesota and University of Virginia
This message may be cited
GCN Circular 6341
Subject
GRB070419A: Kuiper Optical detection
Date
2007-04-20T23:23:49Z (19 years ago)
From
Peter A. Milne at Super-LOTIS <pmilne@as.arizona.edu>
P.A. Milne and G.G. Williams (U Arizona) report on behalf of the
Super-LOTIS team:
The 1.54m Kuiper telescope began R and V-band observations of the error
region of GRB070419A (Swift trigger 276205) at 10:26:37 UT, 27 minutes
after the burst. The OT detected by Chornock et al. (GCN 6304) and
observed by Cenko et al., Urata et al., Rol et al., Smith et al.,
Updike et al., Wren et al., Williams et al., Yoshida et al., Swan et al.
(GCN 6306/6322, 6308/6311, 6309, 6315, 6317, 6324, 6328, 6329, 6339) is
clearly visible in the first image and all subsequent images until
11:36:36 UT.
We used the USNO-B star at RA=12:10:57.57, Dec=+39:55:40.2 to
derive the R and V magnitudes. For the R-band magnitude, we use R=15.22
(Cenko et al. GCN 6306). For the V-band magnitude, we used the
g=15.866 and r=15.447 magnitudes from Cool et al. (GCN 6318),
and derived a V magnitude of V=15.61 using the transformation
equations of Jester et al. (2005).
The R-band magnitude of the afterglow in the first image is:
UT Time delta Time R magnitude error
10:26:37 60.0 s 19.12 0.09
The V-band magnitude of the afterglow in the first V-band image is:
UT Time delta Time V magnitude error
10:35:35 60.0 s 19.66 0.14
This message can be cited.
GCN Circular 6340
Subject
GRB070419a: Swift UVOT observations
Date
2007-04-20T21:57:46Z (19 years ago)
From
Wayne Landsman at GSFC/SSAI <landsman@milkyway.gsfc.nasa.gov>
W. Landsman and M. Stamatikos (NASA/GSFC) report on behalf of the
Swift/UVOT team
The Swift/UVOT began settled observations of GRB 070419A 115 seconds
after the BAT trigger (Stamatikos et al., GCN 6302). The afterglow
first detected by Chornock et al. (GCN 6304) is weakly detected on the
UVOT V-band image. Photometry is difficult due to the presence of a
diffraction spike from a 7th magnitude star 3' distant. The bright
star also precluded use of the UVOT broad-band white filter.
Estimated magnitudes and 3-sigma upper limits are given below:
Filter Start(s) End(s) Exposure(s) Magnitude
-----------------------------------------------------------------
V 115 515 394 20.2 � 0.3
V 869 1204 330 20.0 � 0.3
B 594 739 19 >18.7
U 569 861 58 >19.1
The magnitudes are not corrected for the Galactic reddening of E(B-V)=0.03
The V band magnitudes are consistent with a brightening noted in
previous reports (Williams et al. 6328, Wren et al. 6324, Cenko et al.
6306).
GCN Circular 6339
Subject
GRB 070419A: MARGE Observations
Date
2007-04-20T19:12:03Z (19 years ago)
From
Heather Swan at U.of Michigan/ROTSE <hflewell@umich.edu>
H. Swan (U Mich), I. Smith (Rice), C. Akerlof (U Mich), E. Rykoff (U
Mich), and M. Skinner (Boeing) report on behalf of the MARGE collaboration:
The AEOS Burst Camera (ABC) on the AEOS telescope, located at the Maui
Space Surveillance System on Haleakala, observed the fading counterpart
to GRB070419A (Swift trigger 276205 (GCN 6302)). The images are
unfiltered 10s exposures which started at 10:57:41 UT (~58 minutes after
the trigger) and ended at 11:53:52 UT.
After coadding our images in sets of 10, we detect the OT first
identified by Chornock et al (GCN 6304). A preliminary analysis gives a
magnitude of approximately 20.5+/-0.2 at a mid time of 10:59:11 UT.
Using the SDSS data provided by Cool et al. (GCN 6318), we calibrate the
OT to the r band magnitude of the nearby 20.434 mag star located at
(J2000) RA = 182.73852, DEC = 39.93033. We find that the ABC data fades
as a power law decay with index ~-1.1, consistent with the
detections reported by Nishiura et al. (GCN 6308), Smith et al. (GCN
6315), Updike et al. (GCN 6317), Iizuka et al. (6317) (prior the ABC
observations) and Fu et al. (GCN 6311) (after the ABC observations).
GCN Circular 6329
Subject
GRB 070419A: MITSuME Okayama Observations
Date
2007-04-20T06:48:04Z (19 years ago)
From
Michitoshi Yoshida at Okayama Astrophysical Obs <yoshida@oao.nao.ac.jp>
M. Yoshida, K. Yanagisawa, Y. Shimizu, S. Nagayama (OAO, NAOJ) and
N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration:
We performed optical imaging observation (g', Rc, and Ic) of the
field of GRB 070419A (Stamatikos et al. GCN 6302) with 50cm MITSuME
telescope at Okayama Astrophysical Observatory from UT 10:53 to
UT 13:06 on Apr.19 2007.
We coadded 106 CCD frames for each band. Exposure time of each frame
is 1 minute. We made flux calibration using a USNO B1.0 star close
to the XRT position (12:10:57.57, +39:55:40.2, B=16.14, R=15.22,
I=14.37; see Williams et al. GCN 6328, Cenko et al. GCN 6306). We
detected a faint source in g' band at the position of the optical
transient reported by Chornock et al. (GCN 6304). The g' band magnitude
and three sigma limiting magnitudes for Rc and Ic bands of this source
are listed below.
---------------------------------------------------------------
band mid-UT exp.time brightness
g' Apr. 19 12:00 106 x 1 min. 20.9 +- 0.2 mag
Rc Apr. 19 12:00 106 x 1 min. > 21.5 mag (upper limit)
Ic Apr. 19 12:00 106 x 1 min. > 19.4 mag (upper limit)
---------------------------------------------------------------
GCN Circular 6328
Subject
GRB 070419A: Early Super-LOTIS Observations
Date
2007-04-20T04:03:14Z (19 years ago)
From
Grant Williams at Steward Observatory <ggwilli@mmto.org>
G. G. Williams (MMTO) and P. A. Milne (Steward Observatory), on behalf of
the Super-LOTIS Collaboration, report:
The robotic 0.6-m Super-LOTIS telescope began observing the error box of
GRB 070419A (Swift Trigger 276205, Stamatikos et al. GCN 6302) at
10:01:08.1 UT, 102 seconds after the trigger. Our initial observations
include 5 x 10s exposures, 5 x 20s exposures, and 30 x 60s exposures, all
in the R-band.
We detect the afterglow reported by Chornock et al. (GCN 6304) in our
third (and subsequent) 60 second exposure which began at 10:07:01.8 UT,
456 seconds after the trigger. We do not detect the afterglow in early
single exposures or early summed exposures. This is evidently related to
the brightening reported by Cenko et al. & Wren et al. (GCN 6306 & 6324).
Using the USNO-B star at RA=12:10:57.57, Dec=+39:55:40.2 with R=15.22
(Cenko et al. GCN 6306), we calculate the following R-band magnitudes and
5-sigma upper limits:
t_start (UT) exp t_tot (s) Nsum t_start-t_0 (s) R Mag
----------------------------------------------------------------
10:01:08.1 10 1 102 R > 17.71
10:01:08.1 50 5 102 R > 18.58
10:02:33.1 20 1 187 R > 18.24
10:02:33.1 100 5 187 R > 19.19
10:04:47.9 60 1 322 R > 18.60
10:07:01.8 60 1 456 R = 18.49 +/- 0.22
Additional observations followed our initial set and analysis are ongoing.
GCN Circular 6326
Subject
GRB 070419A Swift-BAT Refined Analysis
Date
2007-04-20T01:10:41Z (19 years ago)
From
Michael Stamatikos at GSFC <michael@milkyway.gsfc.nasa.gov>
M. Stamatikos (GSFC/ORAU), L. Barbier (GSFC), S. D. Barthelmy (GSFC), J.
Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm
(GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC),
T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS), J. Tueller (GSFC) on behalf of
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 070419A
(trigger #276205) (Stamatikos, et al., GCN Circ. 6302). The BAT
ground-calculated position
is RA, Dec = 182.755, 39.903 deg which is
RA(J2000) = 12h 11m 1.1s
Dec(J2000) = 39d 54' 11.0"
with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment). The
coding fraction was 1.
This position is ~1.5 arcmin from the position of the optical afterglow
candidate reported by Chornock et al. (GCN Circ 6304), which was further
confirmed by Cenko et al. (GCN Circ 6306).
The mask-weighted light curve has a nearly symmetric, smooth profile,
although a tail of emission extends to about T+160 sec. The T90 (15-350 keV)
is ~116 +- 6 sec (estimated error including systematics).
The time-averaged spectrum, from T-35 to T+93, is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is 2.35
+- 0.25. The fluence in the 15-150 keV band is 5.6 +- 0.8 x 10^-7 erg/cm^2.
The 1-sec peak photon flux measured from T-1.12 sec in the 15-150 keV band
is 2.8 x 10^-2 ph/cm^2/sec. All the quoted errors are at the 90% confidence
level.
Under a Lambda Cold Dark Matter cosmological model, with Ho ~ 65 km/Mpc/s,
Omega_M ~ 0.30, and Omega_Lambda ~ 0.70, the preliminary Keck absorption
redshift of 0.97, reported by Cenko et al. (GCN Circ 6322), when coupled to
the BAT fluence reported above, results in a preliminary isotropic energy
emission estimate of ~ 1.60 x 10^+51 ergs in the 15-150 keV observed (30-296
keV GRB rest frame) band pass.
GCN Circular 6324
Subject
GRB 070419A: RAPTOR Detection of Early Emission
Date
2007-04-19T23:42:20Z (19 years ago)
From
James Wren at LANL <jwren@nis.lanl.gov>
J. Wren, W.T. Vestrand, P.R. Wozniak, R. White, J. Pergande
of Los Alamos National Laboratory report:
Our Raptor telescopes responded to Swift trigger 276205
(Stamatikos et al., GCN 6302) at 10:00:49.8 UT, 83.7 s after
the trigger and 7.8 s after receiving the GCN packet. We detect
optical emission from the counterpart reported by the KAIT team
(Chornock et al., GCN 6304). Our observations show that the
counterpart brightened from below magnitude 18.8 to 18.44 (+- .15)
at a mid-exposure time of 10:09:27.9 UT (60s duration). The
counterpart then began a slow decline but remained detectable in
our images until we interrupted our observing sequence at
10:47:17 UT for Swift trigger 276212. Our unfiltered images were
calibrated using the R-band magnitudes from the USNO B1.0 catalog.
This information is also being transmitted via VOEvent on the
VOEventNet.
GCN Circular 6322
Subject
GRB 070419: Keck/LRIS Absorption Redshift
Date
2007-04-19T21:54:28Z (19 years ago)
From
S. Bradley Cenko at Caltech <cenko@srl.caltech.edu>
S. B. Cenko, S. Gezari, T. Small (Caltech), D. B. Fox (Penn State), and E.
Berger (Carnegie) report on behalf of a larger collaboration:
We have obtained a spectrum of the optical afterglow of GRB070419A
(Chornock et al., GCN 6304) with the Low-Resolution Imaging Spectrometer
mounted on the 10-m Keck I telescope. Observations consisted of 2 x 900 s
spectra taken at a mean epoch of approximately 11:36 19 April UT (~ 1.62
hr after the burst).
We identify a single strong absorption system, including Mg II, Fe II, Mn
II, and Fe I features, at a preliminary redshift of z = 0.97. Coupled
with the lack of Lyman-alpha absorption down to ~ 3500 A, we consider
this system is likely from the host galaxy of GRB070419A.
GCN Circular 6320
Subject
GRB 070419A, Optical observations
Date
2007-04-19T19:36:25Z (19 years ago)
From
Shashi Bhushan Pandey at ARIES, INDIA <shashi@aries.ernet.in>
S. B. Pandey, Rupak Roy and Saurabh Sharma (ARIES Nainital), on behalf of larger
Indian GRB collaboration
Optical afterglow candidate (GCN 6304) of GRB 070419A, localized by SWIFT
(GCN 6302, trigger 276205), was monitored from ARIES Nainital, India
using 1-m telescope in R_c and I_c filters around 4 hours after the burst.
The total exposure given in R_c filter was 300sec*6 in good sky conditions.
Photometry of the stacked R_c frame poses an upper limit of ~22 mag (around 4.3
hours after the burst) at the location of OT in comparison to nearby
USNO-B1.0 star (GCN 6306).
This message may be cited.
GCN Circular 6318
Subject
GRB070419 - SDSS Pre-Burst Observations
Date
2007-04-19T17:39:28Z (19 years ago)
From
Richard J. Cool at U.of AZ/Steward Obs <rcool@as.arizona.edu>
Richard J. Cool (Arizona), Daniel J. Eisenstein (Arizona), David W. Hogg
(NYU), Michael R. Blanton (NYU), David J. Schlegel (LBNL), J. Brinkmann
(APO),
Donald Q. Lamb (Chicago), Donald P. Schneider (PSU), and Daniel E. Vanden
Berk
(PSU) report:
The Sloan Digital Sky Survey (SDSS) imaged the field of burst GRB070419
prior to the burst. As these data should be useful as a pre-burst comparison
and for calibrating photometry, we are supplying the images and photometry
measurements for this GRB field to the community.
Data from the SDSS, including 5 FITS images, 3 JPGS, and
3 files of photometry and astrometry, are being placed at
http://mizar.as.arizona.edu/~grb/public/GRB070419
We supply FITS images in each of the 5 SDSS bands of a 8'x8' region centered
on the GRB position (ra=182.714 (12:10:51.4), dec=39.9080 (39:54:28.8);
Swift-BAT TRIGGER 276205), as well as 3 gri color-composite JPGs (with
different stretches). The units in the FITS images are nanomaggies per pixel.
A pixel is 0.396 arcsec on a side. A nanomaggie is a flux-density unit equal
to 10^-9 of a magnitude 0 source or, to the extent that SDSS is an AB system,
3.631e-6 Jy. The FITS images have WCS astrometric information.
In the file GRB070419_sdss.calstar.dat, we report photometry and astrometry
of 163 bright stars (r<20.5) within 15' of the burst location. The
magnitudes
presented in this file are asinh magnitudes as are standard in the SDSS
(Lupton
1999, AJ, 118, 1406). Beware that some of these stars are not well-detected
in the u-band; use the errors and object flags to monitor data quality.
In the files GRB070419_sdss.objects_flux.dat and
GRB070419_sdss.objects_magnitudes.dat, we report photometry of 415
objects detected within 6' of the GRB position. We have removed saturated
objects and objects with model magnitudes fainter than 23.0 in the r-band.
The fluxes listed in GRB070419_sdss.objects_flux.dat are in nanomaggies
while the magnitudes listed in GRB070419_sdss.objects_magnitudes.dat are
asinh magnitudes.
All quantities reported are standard SDSS photometry, meaning that they are
very close to AB zeropoints and magnitudes are quoted in asinh magnitudes.
Photometric zeropoints are known to about 2% rms. None of the photometry
is corrected for dust extinction. The Schlegel, Finkbeiner, and Davis
(1998) predictions for this region are A_U=0.143 mag, A_g=0.105 mag, A_r =
0.076 mag, A_i=0.058 mag, and A_z=0.041 mag.
The file GRB070419_sdss.spectro.dat contains a list of the 1 objects with
SDSS spectroscopy within 6 arcminutes of the GRB position. In addition to
the redshift and 1-sigma error for each object, this file also lists the
object spectroscopic classification.
SDSS astrometry is generally better than 0.1 arcsecond per coordinate.
Users requiring high precision astrometry should take note that the SDSS
astrometric system can differ from other systems such as those used in other
notices; we have not checked the offsets in this region.
More detailed information pertaining to our SDSS GRB releases can be found
in our initial data release paper (Cool et al. 2006, PASP 118, 733). See the
SDSS DR4 documentation for more details: http://www.sdss.org/dr5.
These data have been reduced using a slightly different pipeline than that
used for SDSS public data releases. We cannot guarantee that the values here
will exactly match those in the data release in which these data are
included.
In particular, we expect the photometric calibrations to differ by of order
0.01 mag.
This note may be cited, but please also cite the SDSS data release paper,
Adelman-McCarthy et al. (2006, ApJS, 162, 38), when using the data or
referring to the technical documentation.
GCN Circular 6317
Subject
GRB 070419A: SARA observations
Date
2007-04-19T17:31:41Z (19 years ago)
From
Adria C. Updike at Clemson U <aupdike@clemson.edu>
A. C. Updike, D. H. Hartmann (Clemson University) and K. Rumstay
(Valdosta University) report on behalf of the Clemson GRB Follow-Up Team:
We imaged the field of GRB 070419A (GCN 6302, Stamatikos et al.)
beginning 54 minutes after the trigger (276205) with the SARA 0.9m at
Kitt Peak under good weather conditions. In 16 minutes of stacked
images, we see a faint object near our detection limit at the location
of the afterglow (GCN 6304, Charnack et al.). We estimate the R-band
magnitude to be 20 +/- 0.5 based on calibration to 5 USNO B1.0 stars.
The Clemson University GRB Response Site may be found at:
http://people.clemson.edu/~kgarime/burst/index.php
The SARA Homepage can be found at:
http://saraobservatory.org
This message may be cited.
GCN Circular 6316
Subject
GRB 070419A: NAYUTA Optical Observation
Date
2007-04-19T16:21:08Z (19 years ago)
From
Ryo Iizuka at NHAO <iizuka@nhao.go.jp>
R. Iizuka, K. Matsuda, H. Naito and F. Tsumuraya
report on behalf of NHAO.
We observed the field of GRB 070419A (GCN 6302) with MINT
on the 2.0-m NAYUTA telescope at Nishi-Harima Astronomical
Observatory, Japan. We took images for a total of 100 sec in
R-band filter on 2007 Apr 19 10:55 UT (56 minutes after the burst).
The afterglow was detected with 20.1 mag relative to USNO-B stars.
GCN Circular 6315
Subject
GRB 070419A: Faulkes Telescope North Optical Observations
Date
2007-04-19T15:38:29Z (19 years ago)
From
James Smith at ARI,Liverpool John Moors U <rjs@astro.livjm.ac.uk>
R.J. Smith, C.G. Mundell, S.N. Fraser, I.A. Steele, C.J. Mottram, A.
Melandri, D.F. Bersier, M.F. Bode (Liverpool JMU), C. Guidorzi
(Uni-Bicocca/INAF-OAB), A. Gomboc (Ljubljana), P. O'Brien, E. Rol, N.
Bannister (U. Leicester) report on behalf of the RoboNet GRB
collaboration
The 2-m Faulkes North Telescope (Hawaii) reacted to the Swift burst
GRB070419A
(Stamatikos et al. GCN 6302). Observations were delayed by scheduled
engineering
work and only started about 37 min after the trigger time. BRi
observations continued
until 104min after the trigger.
We detect the optical transient reported by Chornock et al (GCN 6304)
in R and i' band filters
and measure a power law decay index of ~ 1.5 throughout the hour of
observation.
UTC minutes_since_trigger Mag
10:49:46.5 50.36 g' > 19.8 (limit only)
10:51:20.8 51.91 r' = 20.37
10:53:07.9 53.70 i' = 20.22
Magnitudes are based on comparison with SDSS magnitudes of the adjacent
star
SDSS J121057.55+395539.9.
The target has set and further observations are not currently ongoing
with this telescope.
GCN Circular 6313
Subject
GRB 070419A: Optical and IR observations with KANATA
Date
2007-04-19T14:46:36Z (19 years ago)
From
Makoto Uemura at Hiroshima U <uemuram@hiroshima-u.ac.jp>
M. Uemura, A. Arai, and T. Uehara (Hiroshima Univ.),
report on behalf of the KANATA GRB team:
We took optical and IR images of the field of GRB070419A (GCN 6302) at
11:01-11:12 UT 19 Apr. using TRISPEC attached to the KANATA
1.5-m telescope at Higashi-Hiroshima Observatory, Japan.
We obtained 10 sets of V, J, and Ks-band images with a 63, 60,
and 48-s exposure times under thin clouds.
No new object was significantly detected in the combined image
(19.46322 Apr. 2007 UT). Limit magnitudes are 20.0, 17.2, and 15.0 mag
in V-, J-, and Ks-band, respectively, using the USNO A2.0 and
2MASS catalog.
GCN Circular 6311
Subject
GRB 070419A: Lulin Optical observation
Date
2007-04-19T14:41:04Z (19 years ago)
From
Yuji Urata at Saitama U <urata@crystal.heal.phy.saitama-u.ac.jp>
K.J. Fu, Y.H. Lee, K.Y. Huang and Y. Urata report on behalf of EAFON
"We observed the optical afterglow of GRB070419A (Stamatikos et al
#6302, Chornock et al #6304, Cenko et al #6306, Nishiura et al. #6308
and Rol et al #6309) with the Lulin One-meter Telescope started from
11:49 UT. The afterglow at 2.0 hours after the burst is visible in our
R-band combined image with R = 21.8+/-0.3 (compared with USBO-B1.0 catalogue)."
Further observations and analysis are in progress.
GCN Circular 6310
Subject
GRB070419A, optical observation
Date
2007-04-19T14:30:54Z (19 years ago)
From
Eri Sonoda at U of Miyazaki/Japan <sonoda@astro.miyazaki-u.ac.jp>
R. Hara, E.Sonoda, S.Maeno, H. Tanaka, N. Ohmori, M.Yamauchi
(University of Miyazaki)
We have observed the field covering the error circle of
GRB070419A (GCN 6302, M. Stamatikos et al.) with
the unfiltered CCD camera on the 30-cm telescope at
University of Miyazaki.
The observation was started 10:24:34 UT, ~25 min
after the Swift trigger time.
We have compared our data of 30 sec exposures
with the USNO-A2.0 catalog,
the upper limits are as follows:
--------------------------------------------------------------
Start(UT) End(UT) Num. of frames Limit (mag.)
--------------------------------------------------------------
10:42:40 10:43:10 1 ~16.2
10:42:40 10:53:36 10 ~17.7
---------------------------------------------------------------
GCN Circular 6309
Subject
Infrared detection of GRB070419A with UKIRT
Date
2007-04-19T14:10:53Z (19 years ago)
From
Evert Rol at U.Leicester <er45@star.le.ac.uk>
E. Rol, N. Tanvir (U. of Leicester), T. Kerr (JAC), report for a
larger collaboration:
We observed the field of GRB070419A with UKIRT-WFCAM, starting 39
minutes after the GRB trigger (Stamatikos et al., GCN 6302). We find
the following magnitudes for the infrared counterpart of GRB070419A:
T filter magn error(magn)
(hours post trigger)
--------------------------------------------------
0.654 J 18.27 0.08
0.734 H 17.83 0.13
0.814 J 18.56 0.09
0.896 K 17.26 0.18
1.665 K 18.30 0.18
The magnitudes are calibrated with respect to the 2MASS catalogue.
GCN Circular 6308
Subject
GRB 070419A: Kiso Optical observation
Date
2007-04-19T13:29:46Z (19 years ago)
From
Yuji Urata at Saitama U <urata@crystal.heal.phy.saitama-u.ac.jp>
S. Nishiura, H. Tomita, Y. Urata and K.Y. Huang
report on behalf of EAFON team
"We have imaged the GRB 070419A field (Stamatikos et al. #6302) with
the Kiso 1.05m Schmidt telescope. The optical afterglow reported by
Chornock et al (#6304) and Cenko et al. (#6306) is visible in our B
and R band images. We also confirmed the decaying during our
observation. The afterglow brightness at 51 min after the burst is
R~20.1 mag."
Further observations and analysis are in progress.
GCN Circular 6306
Subject
GRB 070419: P60 Confirmation of Optical Afterglow
Date
2007-04-19T11:16:54Z (19 years ago)
From
S. Bradley Cenko at Caltech <cenko@srl.caltech.edu>
S. B. Cenko (Caltech) and D. B. Fox (Penn State) report on behalf of a
larger collaboration:
We have imaged the field of GRB070419 (Stamatikos et al., GCN 6302) with
the automated Palomar 60-inch telescope. The candidate identified by
Chornock et al. (GCN 5304) is visible in our images and variable; we
therefore confirm it is the optical afterglow of GRB070419. Specifically,
we measure the following R-band magnitudes:
Mean Date Time Since Burst Magnitude
--------------------------------------------------------------------------
10:05:18 5.87 min 19.7
10:10:31 11.08 min 18.7
The above magnitudes were calculated assuming a magnitude of R=15.22
for the the USNO-B reference star located at 12:10:57.57, +39:55:40.2.
Further observations are planned.
GCN Circular 6304
Subject
GRB 070419 optical afterglow candidate
Date
2007-04-19T10:46:06Z (19 years ago)
From
Ryan Chornock at UC Berkeley <chornock@astro.berkeley.edu>
R. Chornock, W. Li, A. V. Filippenko, and the KAIT GRB team (UC Berkeley)
report:
A faint (mag~19) optical source is present in Katzman Automatic Imaging
Telescope (KAIT) images at coordinates (J2000) 12:10:58.82 +39:55:33.9
The first detection was in a 45sec unfiltered image starting at 10:05:19 UT.
This position is consistent with the XRT position (GCN 6302) and the source does
not appear to be present in DSS images.
GCN Circular 6303
Subject
GRB 070419A: ROTSE-III Optical Limits
Date
2007-04-19T10:33:32Z (19 years ago)
From
Brad Schaefer at LSU <schaefer@grb.phys.lsu.edu>
B. E. Schaefer (Louisiana State), F. Yuan (U Mich), S.A. Yost (U Mich),
report on behalf of the ROTSE collaboration:
ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB
070419A (Swift trigger 276205), producing images beginning 6.3 s after the
GCN notice time. An automated response took the first image at 10:00:47.3
UT, 81.2 s after the burst, under excellent conditions. We took 10 5-sec,
10 20-sec and 20 60-sec eposures, with further exposures still continuing.
These unfiltered images are calibrated relative to USNO A2.0 (R).
There is a bright star in the BAT error circle, but this is well removed
from the XRT position. Comparison to the DSS (second epoch) reveals no new
sources within the 3-sigma XRT error circle, for both single images and
coadding into sets of 10; the field is not crowded. Individual images
have limiting magnitudes ranging from 15.2-17.6; we set the following
specific limits.
start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd?
--------------------------------------------------------------------
10:00:47.3 10:00:52.3 5 16.0 81.2 N
10:00:47.3 10:01:54.4 67 17.8 81.2 Y
GCN Circular 6302
Subject
GRB 070419: Swift detection of a burst
Date
2007-04-19T10:30:53Z (19 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
M. Stamatikos (NASA/ORAU), D. N. Burrows (PSU), S. Campana (INAF-OAB),
G. Cusumano (INAF-IASFPA), P. A. Evans (U Leicester),
N. Gehrels (NASA/GSFC), C. Gronwall (PSU),
C. Guidorzi (Univ Bicocca&INAF-OAB), V. La Parola (INAF-IASFPA),
W. B. Landsman (NASA/GSFC), V. Mangano (INAF-IASFPA),
C. B. Markwardt (GSFC/UMD), P. T. O'Brien (U Leicester),
D. M. Palmer (LANL), A. M. Parsons (GSFC),
P. Romano (Univ. Bicocca & INAF-OAB), B. Sbarufatti (INAF-IASFPA),
G. Stratta (ASDC), S. D. Vergani (DIAS-DCU) and
H. Ziaeepour (UCL-MSSL) report on behalf of the Swift Team:
At 09:59:26 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 070419 (trigger=276205). Swift slewed immediately to
the burst. The BAT on-board calculated location is
RA, Dec 182.714, +39.908 which is
RA(J2000) = 12h 10m 51s
Dec(J2000) = +39d 54' 30"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve suggests emission from
T-10 to T+20 with a peak count rate of ~500 counts/sec (15-350 keV),
at ~4 sec after the trigger. However, as for most image triggers,
the TDRSS light curve data is noisy and we will require the Malindi
pass data for a more definitive analysis.
The XRT began observing the field at 10:01:18 UT, 113 seconds after
the BAT trigger. XRT found a bright, fading and uncatalogued X-ray
source. The on ground calculated position is RA, Dec 182.7462,
+39.9245 which is
RA(J2000) = 12h 10m 59.1s
Dec(J2000) =39d 55' 28.2"
with an uncertainty of 7.0 arcseconds (radius, 90%
containment). The given uncertainty takes into account the presence
of a nearby CCD bad column. This location is 110 arcseconds from
the BAT on-board position, within the BAT error circle. The initial
flux in the 2.5s image was 3.7e-09 erg/cm2/s (0.2-10 keV).
UVOT took a finding chart exposure of 400 seconds with the V filter
starting 115 seconds after the BAT trigger. No afterglow candidate
has been found in the initial data products. The 2.7'x2.7' sub-image
covers 100% of the XRT error circle. The typical 3-sigma upper limit
has been about 18.5 mag. The 8'x8' region for the list of sources
generated on-board covers 100% of the XRT error circle. The list of
sources is typically complete to about 18.0 mag. No correction has been made
for the expected extinction of about 0.1 magnitudes. We note there is
a 7th magnitude star 3 arcminutes from the XRT position.