GRB 141004A
GCN Circular 16878
Subject
GRB 141004A: Swift detection of a burst with an optical counterpart
Date
2014-10-04T23:29:48Z (11 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
V. D'Elia (ASDC), S. D. Barthelmy (GSFC), N. Gehrels (NASA/GSFC),
L. Izzo (URoma/ICRA), J. A. Kennea (PSU), F. E. Marshall (NASA/GSFC),
D. M. Palmer (LANL) and B. Sbarufatti (INAF-OAB/PSU) report on behalf
of the Swift Team:
At 23:20:54 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 141004A (trigger=614390). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 76.730, +12.833 which is
RA(J2000) = 05h 06m 55s
Dec(J2000) = +12d 49' 59"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a single FRED
structure with a duration of about 8 sec. The peak count rate
was ~17000 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 23:21:54.2 UT, 59.9 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 76.73435, 12.81935 which is equivalent
to:
RA(J2000) = 05h 06m 56.24s
Dec(J2000) = +12d 49' 09.7"
with an uncertainty of 4.3 arcseconds (radius, 90% containment). This
location is 51 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. We
cannot determine whether the source is fading at the present time.
A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (3.14 x
10^21 cm^-2, Willingale et al. 2013), with an excess column of 5.3
(+5.50/-4.31) x 10^21 cm^-2 (90% confidence).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 64 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 05:06:56.14 = 76.73391
DEC(J2000) = +12:49:11.3 = 12.81981
with a 90%-confidence error radius of about 0.61 arc sec. This position is 2.3
arc sec. from the center of the XRT error circle. The estimated magnitude is
17.39 with a 1-sigma error of about 0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.32.
Burst Advocate for this burst is V. D'Elia (delia AT asdc.asi.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.)
GCN Circular 16879
Subject
GRB 141004A: a long GRB detected by INTEGRAL
Date
2014-10-05T00:20:44Z (11 years ago)
From
Sandro Mereghetti at IASF/CNR <sandro@iasf-milano.inaf.it>
S.Mereghetti (IASF-Milano), D.Gotz (CEA, Saclay), E.Bozzo, C.Ferrigno
(ISDC, Versoix), 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 23:21:02 of October 4, 2014
The refined coordinates (J2000) are:
R.A.= 76.7496 deg
DEC.= +12.8235 deg
with an uncertainty of 2 arcmin (90% c.l.).
THis burst has also been detected by Swift (D'Elia et al. GCN 16878)
A plot of the light curve will be posted at
http://ibas.iasf-milano.inaf.it/IBAS_Results.html
GCN Circular 16880
Subject
GRB 141004A: 1.23m CAHA optical observations
Date
2014-10-05T01:02:09Z (11 years ago)
From
Javier Gorosabel at IAA-CSIC <jgu@iaa.es>
J. Gorosabel (IAA-CSIC/UPV-EHU), S. Hellmich (DLR), S. Mottola (DLR), on
behalf of a larger collaboration report:
We observed the GRB 141004A (D'Elia et al. GCN 16878) field with the 1.23m
CAHA telescope. The observations were done in the Ic-band starting on Oct
4.9969 UT (34.6 minutes post GRB). A preliminary analysis detects a faint
optical object located at (RA, DEC)=05:06:56.17, 12:49:10.8 (+/-0.7"), so
consistent with the UVOT position. We estimate a preliminary Vega
magnitude of Ic~19.2, calibrated against the USNO B1.0 catalog.
GCN Circular 16881
Subject
GRB 141004A: TNG photometric and spectroscopic observations
Date
2014-10-05T02:49:18Z (11 years ago)
From
Valerio D'Elia at ASDC <delia@asdc.asi.it>
V. D'Elia (INAF/OAR & ASI/ASDC), S. Covino (INAF/OAB), M. Cecconi and
Carmen Padilla (INAF/TNG) report on behalf of the CIBO collaboration:
We observed the optical afterglow of GRB 141004A (D'Elia et al., GCN
16878; Mereghetti et al. GCN 16879) on 2014 October 5 with the 3.6m
TNG telescope located in the Canary Islands, equipped with the DOLORES
operated in both imaging and spectroscopic mode. The observations were
carried out under good weather conditions (seeing about 1.5) at high
airmass.
In a 180 s image started at 01:41 UT (~2.3 hr after the GRB), the
afterglow has a magnitude r = 20.9 +/- 0.1 (AB), calibrated against
the APASS catalog. No correction has been applied for the Galactic
extinction. The position of the afterglow is
RA: 05:06:56.17
Dec: 12:49:10.54,
consistent with the UVOT detection (D'Elia et al. GCN 16878) and with
the CAHA observation (Gorosabel et al., GCN 16880). We also detect a
fainter object (possibly extended) 5" eastward to the afterglow.
We also obtained two optical spectra, each one lasting 1200 s, using
the grism LR-B covering the wavelength range 3000 - 8000 AA. The
observations started at 01:00 UT (~1.7 hr after the GRB). Using a
preliminary wavelength calibration, in the co-added spectrum we detect
a faint continuum extending down to 4000 A. No obvious absorption or
emission features are detected in our preliminary analysis of the
afterglow spectrum.
GCN Circular 16883
Subject
GRB 141004A: Enhanced Swift-XRT position
Date
2014-10-05T06:33:18Z (11 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester)
report on behalf of the Swift-XRT team.
Using 2078 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 141004A, 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 = 76.73357, +12.81944 which is equivalent
to:
RA (J2000): 05h 06m 56.06s
Dec (J2000): +12d 49' 10.0"
with an uncertainty of 1.6 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 16886
Subject
GRB 141004A: Monte Agliale Observatory optical observations
Date
2014-10-05T08:55:29Z (11 years ago)
From
Fabrizio Ciabattari at Monte Agliale Obs <fabciaba@alice.it>
F. Ciabattari, S. Donati, E. Mazzoni, G. Petroni and M. Rossi (Monte Agliale Observatory, Borgo a
Mozzano, Italy) report:
We observed the field of GRB 141004A (D'Elia et al. GCN 16878) with the automatic
0.5m f/4.6 Newtonian telescope + FLI Proline PL4710 camera at
Monte Agliale Observatory (Borgo a Mozzano, Italy, MPC code 159).
The observations started at 2014-10-04 23:25:05 UT (~ 4 minutes after the
burst trigger) and we co-added 19 unfiltered CCD exposures of 30 seconds each.
We detect a new source of mag. R = 17.6 +/-0.2 (USNO-B1 catalogue, not corrected
for Galactic extinction in the direction of the GRB) at the following position:
R.A.(J2000) = 05h 06m 56.18s
Dec.(J2000) = +12d 49' 10.9"
FITS files are available on request from fabciaba@alice.it
The message may be cited.
GCN Circular 16887
Subject
GRB 141004A: RATIR Optical Observations
Date
2014-10-05T09:34:12Z (11 years ago)
From
Owen Littlejohns at Az State U <olittlej@asu.edu>
Owen Littlejohns (ASU), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer
(UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC),
Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja
(GSFC), Enrico Ramirez-Ruiz (UCSC), Jos�� A. de Diego (UNAM), Leonid
Georgiev (UNAM), Jes��s Gonz��lez (UNAM), Carlos Rom��n-Z����iga (UNAM),
Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report:
We observed the field of GRB 141004A (D'Elia, et al., GCN 16878) with
the Reionization and Transients Infrared Camera (RATIR; www.ratir.org)
on the 1.5m Harold Johnson Telescope at the Observatorio Astron��mico
Nacional on Sierra San Pedro M��rtir from 2014/10 5.30 to 2014/10 5.35
UTC (7.82 to 9.15 hours after the BAT trigger), obtaining a total of
1.07 hours exposure in the r and i bands.
We detect the source reported by Swift/UVOT (D'Elia, et al., GCN 16878)
and the 3.6m TNG telescope (D'Elia, et al., GCN 16881). We obtain the
following detections:
r 22.35 +/- 0.13
i 22.11 +/- 0.12
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB. In comparison to the earlier TNG
observations we note that the GRB has faded with an approximate
temporal power-law index of t^(-1.0).
We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
M��rtir.
GCN Circular 16890
Subject
GRB 141004A: Swift/UVOT Detection
Date
2014-10-05T16:07:41Z (11 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (UCL-MSSL) and V. D'Elia (ASDC) report on behalf of
the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 141004A
65 s after the BAT trigger (D'Elia et al., GCN Circ. 16878).The GRB was
also detected by Integral (Mereghetti et al, GCN Circ. 16879), and in the
optical by CAHA (Gorosabel et al, GCN Circ. 16880), TNG (D'Elia et al.,
GCN Circ. 16881), at Monte Agliale Observatory (Ciabatta et al. GCN Circ.
16886) and by RATIR (Littlejohns et al., GCN Circ. 16887). A source
consistent with the XRT position (Osborne et al. GCN Circ. 16883)
is detected in the initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 05:06:56.14 = 76.73393 (deg.)
Dec (J2000) = +12:49:11.3 = 12.81981 (deg.)
with an estimated uncertainty of 0.43 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 65 215 147 17.64 +/- 0.07
v 606 1922 156 18.94 +/- 0.24
b 532 1156 58 18.94 +/- 0.20
u 277 527 246 17.93 +/- 0.09
w1 656 1453 97 18.67 +/- 0.24
m2 806 7273 216 >20.5
w2 582 13683 582 20.69 +/- 0.35
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.32 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 16891
Subject
GRB141004A: NOT imaging and spectroscopy
Date
2014-10-05T16:28:34Z (11 years ago)
From
Steve Schulze at U of Iceland <sts30@hi.is>
S. Schulze (PUC, MAS), T. Kruehler (ESO Chile), D. Xu, J. P. U. Fynbo (DARK/NBI), N. R. Tanvir (U Leicester), P. Jakobsson (U. Iceland), S. Galleti (INAF-OAB) report on behalf a larger collaboration:
We observed the field of GRB 141004A (D'Elia et al. GCN 16878, Mereghetti et al. GCN 16879) with the 2.5-m Nordic Optical Telescope (NOT) equipped with ALFOSC. Observations started at 01:52:22 UT on October 5 (i.e., 2.52 hr after the burst). We obtained a 200-s image in the R band.
The afterglow reported in D'Elia et al. (GCN 16878) and Gorosabel et al. (GCN 16880) is clearly detected. It has an R-band magnitude of 20.6 mag (not corrected for foreground extinction), calibrated against several USNO stars. The mid-exposure time is 2.55 hr after the trigger. Compared to D�Elia et al (GCN 16881), the brightness of the afterglow did not decrease.
In addition, we obtained an optical spectrum, with a total exposure of 3 x 1800 s, using Grism #4 and covering the wavelength range 3750 - 9000 AA at a resolution of 17 AA. Observations started at 02:17:23 UT (i.e. 2.9 hr after the burst). The continuum is detected down to ~3750 AA. No absorption line is visible in the spectrum. A tentative emission line is detected at 5866.4 AA, which could be [OIII]-5007 at z=0.17 or [OII] at z=0.57. A higher S/N spectrum is needed to elucidate the nature of this feature.
GCN Circular 16892
Subject
GRB 141004A: Swift-BAT refined analysis
Date
2014-10-05T17:11:58Z (11 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
V. D'Elia (ASDC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), 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 141004A (trigger #614390)
(D'Elia, et al., GCN Circ. 16878). The BAT ground-calculated position is
RA, Dec = 76.721, 12.828 deg, which is
RA(J2000) = 05h 06m 53.0s
Dec(J2000) = +12d 49' 41.2"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
The mask-weighted light curve shows a single FRED peak starting with a weak
emission at T-1 sec, the FRED peak starting at T_0.0, peaking at T+0.1 sec,
and returning to baseline at ~T+20 sec. T90 (15-350 keV) is 3.92 +- 1.07 sec
(estimated error including systematics).
The time-averaged spectrum from T-0.84 to T+5.34 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.86 +- 0.08. The fluence in the 15-150 keV band is 6.7 +- 0.3 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T-0.06 sec in the 15-150 keV band
is 6.1 +- 0.3 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/614390/BA/
GCN Circular 16896
Subject
GRB 141004A: Swift-XRT refined Analysis
Date
2014-10-05T21:30:04Z (11 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), C. Pagani (U.
Leicester), A. Maselli (INAF-IASFPA), A. Melandri (INAF-OAB), B.
Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), J.A. Kennea (PSU), V.
Mangano (PSU) and V. D'Elia report on behalf of the Swift-XRT team:
We have analysed 7.1 ks of XRT data for GRB 141004A (D'Elia et al. GCN
Circ. 16878), from 46 s to 54.0 ks after the BAT trigger. The data
comprise 5 s in Windowed Timing (WT) mode (taken while Swift was
slewing), with the remainder in Photon Counting (PC) mode. The enhanced
XRT position for this burst was given by Osborne et al. (GCN Circ.
16883).
The light curve can be modelled with an initial power-law decay with an
index of alpha=0.66 (+0.08, -0.11), followed by a break at T+3318 s to
an alpha of 1.9 (+0.7, -0.6).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.79 (+0.21, -0.12). The
best-fitting absorption column is consistent with 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 4.2 x 10^-11 (5.7 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 3.1 (+/-1.1) x 10^21 cm^-2
Galactic foreground: 3.1 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index: 1.79 (+0.21, -0.12)
If the light curve continues to decay with a power-law decay index of
1.9, the count rate at T+24 hours will be 4.5 x 10^-4 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.9 x
10^-14 (2.6 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/00614390.
This circular is an official product of the Swift-XRT team.
GCN Circular 16899
Subject
GRB 141004A: GROND observations
Date
2014-10-06T19:23:19Z (11 years ago)
From
Sebastian Schmidl at TLS Tautenburg <schmidl@tls-tautenburg.de>
S. Schmidl (TLS Tautenburg), J. F. Graham, and J. Greiner
(both MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 141004A (Swift trigger 614390; V. D'Elia et
al., GCN #16878) 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).
We detect the afterglow at the UVOT position reported by V. D'Elia et al.
(GCN #16878). From coadded observations, starting on October 06 and
spanning from 05:31 to 09:09 UT, we report the following preliminary AB
magnitudes of:
g' = 24.6 +/- 0.3,
r' = 24.0 +/- 0.2,
i' = 23.5 +/- 0.2, and
z' = 23.4 +/- 0.2.
Given magnitudes are calibrated against GROND zeropoints and
are not corrected for the expected Galactic foreground extinction
corresponding to a reddening of E_(B-V)=0.32 mag in the direction of the
burst (Schlegel et al. 1998).
GCN Circular 16900
Subject
GRB 141004A: Fermi GBM observation
Date
2014-10-06T19:47:12Z (11 years ago)
From
Veronique Pelassa at UAH <vero.pelassa@gmail.com>
V. Pelassa (UAH) reports on behalf of the Fermi GBM Team:
"At 23:20:54.42 UT on 4 October 2014, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 141004A (trigger 434157657 / 141004973),
which was also detected by the Swift/BAT (D'Elia et al. 2014, GCN 16878)
and the INTEGRAL/IBIS (Mereghetti et al 2014, GCN 16879).
The GBM on-ground location is consistent with the Integral position, which
lies at an angle of 100.4 degrees from the Fermi LAT boresight.
The GBM light curve consists of a short FRED peak followed by a faint tail
with a duration (T90) of about 3 s (50-300 keV).
The time-averaged spectrum from T0-0.320 s to T0+0.768 s (main peak) is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.3 +/- 0.1 and
the cutoff energy, parameterized as Epeak, is 147 +/- 28 keV
(Castor stat 398.59 for 365 d.o.f.).
The event fluence (10-1000 keV) in this time interval is
(2.2 +/- 0.2)E-06 erg/cm^2. The 64-msec peak photon flux measured
starting from T0+0.000 s in the 10-1000 keV band
is 18 +/- 2 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
GCN Circular 16902
Subject
GRB141004A: Host galaxy redshift form GTC
Date
2014-10-07T10:39:48Z (11 years ago)
From
Antonio de Ugarte Postigo at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), C.C. Thoene (IAA-CSIC),
D. Malesani (DARK/NBI), S. Schulze (PUC, MAS), R. Sanchez-Ramirez
(UPV/EHU, IAA-CSIC), J. Gorosabel (UPV/EHU, IAA-CSIC),
C.A. Alvarez Iglesias (GTC, IAC), J. Molgo (GTC), and M. Rivero (GTC)
report on behalf of a larger collaboration:
We obtained spectroscopy of the optical counterpart of GRB 141004A
(D'Elia et al., GCN 16878, Mereghetti et al., GCN 16879) with OSIRIS at
the 10.4m GTC telescope on October 7, starting at 5:10 UT (~30 hr after
the GRB). In a preliminary reduction of a 2x600 s exposure with the
R1000R grism (covering from 5100 to 10000 A with a resolution of ~1000),
we detected several emission lines corresponding to [O II], H-beta and
[O III] at a common redshift of 0.573. This confirms that the tentative
emission line detection reported by Schulze et al. (GCN 16891) was
indeed real and that it corresponds to the [O II] 3727/3729 doublet.
We also detect emission from another galaxy within the slit at a similar
redshift of 0.571, with a projected distance of 22" to the East, which
corresponds to ~150 kpc at that redshift, probably belonging to the same
galaxy group. The nearby galaxy reported by D'Elia et al. (GCN 16881)
shows multiple emission features at a redshift of 0.279, and it is therefore
unrelated to the GRB.
GCN Circular 16936
Subject
GRB 141004A: La Palma late-time observations and possible brightening
Date
2014-10-20T21:09:31Z (11 years ago)
From
Steve Schulze at U of Iceland <sts30@hi.is>
S. Schulze (PUC, MAS), A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), K. Wiersema (U. Leicester), D. Xu (DARK/NBI), N. R. Tanvir (U. Leicester), D. Malesani, J. P. U. Fynbo (DARK/NBI), P. Jakobsson (U. Iceland), V. Nascimbeni (INAF/OAPd), J. Harmanen (NOT), and O. Vaduvescu (ING) report on behalf of a larger collaboration:
We monitored the optical counterpart of GRB 141004A (D'Elia et al., GCN 16878; Mereghetti et al., GCN 16879) with the 2.5-m Nordic Optical Telescope (NOT), the 4.2-m William Herschel Telescope (WHT), and the 10.4-m Gran Telescopio Canarias (GTC). The latest NOT observation was secured with ALFOSC on October 14.17 (9.19 days after the burst) and consisted of 9x240-s in i' band. In the same night we obtained a deep 8x300-s image with ACAM mounted at the WHT in r' band starting at October 14.17. A GTC observation was secured on October 18.24 (13.27 days after the burst) and consisted of 3x180 s in r' band and 4x120 s in i' band.
We applied differential photometry to check for variability using six unsaturated nearby stars. The transient did not change its brightness in r� band by more than ~0.10 mag, but in the i' band our photometry indicates a tentative brightening by 0.46 +/- 0.27 mag.
While the detected variability is only marginally significant, this behaviour is consistent with the emergence of a SN similar to SN 1998bw, both in terms of brightness and color evolution. We encourage further follow-up to test for the presence of an emerging SN.
GCN Circular 16937
Subject
GRB 141004A: RATIR Late Time Optical and NIR Observations
Date
2014-10-21T21:58:12Z (11 years ago)
From
Owen Littlejohns at Az State U <olittlej@asu.edu>
Owen Littlejohns (ASU), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer
(UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC),
Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja
(GSFC), Enrico Ramirez-Ruiz (UCSC), Jos�� A. de Diego (UNAM), Leonid
Georgiev (UNAM), Jes��s Gonz��lez (UNAM), Carlos Rom��n-Z����iga (UNAM),
Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report:
We observed the field of GRB 141004A (D'Elia, et al., GCN 16878) with
the Reionization and Transients Infrared Camera (RATIR; www.ratir.org)
on the 1.5m Harold Johnson Telescope at the Observatorio Astron��mico
Nacional on Sierra San Pedro M��rtir from 2014/10 21.31 to 2014/10 21.51
UTC (392.08 to 396.95 hours after the BAT trigger), obtaining a total
of 3.89 hours exposure in the r, i and z bands.
We continue to detect the source reported from the previous epoch of
RATIR observations (Littlejohns, et al., GCN 16887). We obtain the
following detections and upper limit (3-sigma):
r 24.21 +/- 0.24
i 23.24 +/- 0.14
z > 21.47
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.
These magnitudes suggest the source to remain brighter than expected if
determined purely from a typical GRB power-law decay. This may
corroborate the claim of re-brightening (Schulze, et al., GCN 16936),
however, it may also indicate the detection of the host galaxy (de Ugarte
Postigo, et al., GCN 16902). We also note that these magnitudes are
broadly consistent with those observed by GROND at an approximate epoch
of 32 hours after the initial Swift/BAT trigger (Schmidl, et al., GCN
16899).
We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
M��rtir.
GCN Circular 16963
Subject
GRB 141004A: Continued RATIR Late Time Optical and NIR Observations
Date
2014-10-26T19:23:33Z (11 years ago)
From
Owen Littlejohns at Az State U <olittlej@asu.edu>
Owen Littlejohns (ASU), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer
(UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska
(UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora
Troja (GSFC), Enrico Ramirez-Ruiz (UCSC), Jos�� A. de Diego (UNAM),
Leonid Georgiev (UNAM), Jes��s Gonz��lez (UNAM), Carlos Rom��n-Z����iga
(UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report:
We again observed the field of GRB 141004A (D'Elia, et al., GCN 16878)
with the Reionization and Transients Infrared Camera (RATIR;
www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio
Astron��mico Nacional on Sierra San Pedro M��rtir from 2014/10 26.26 to
2014/10 26.52 UTC (21.27 to 21.55 days after the BAT trigger),
obtaining a total of 4.98 hours exposure in the r, i and z bands.
We continue to detect the source reported in previous epochs of RATIR
observations (Littlejohns, et al., GCN 16937, Littlejohns, et al., GCN
16887), with the following detections and upper limit:
r 23.94 +/- 0.20
i 23.38 +/- 0.15
z > 20.97
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB. These magnitudes are broadly
consistent with our previous epoch of observations (Littlejohns, et al.,
GCN 16937). Further observations are planned.
We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
M��rtir.
GCN Circular 17003
Subject
GRB 141004A: Continued Late Time RATIR Optical and NIR Observations
Date
2014-10-31T18:59:43Z (11 years ago)
From
Owen Littlejohns at Az State U <olittlej@asu.edu>
Owen Littlejohns (ASU), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer
(UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC),
Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja
(GSFC), Enrico Ramirez-Ruiz (UCSC), Jos�� A. de Diego (UNAM), Leonid
Georgiev (UNAM), Jes��s Gonz��lez (UNAM), Carlos Rom��n-Z����iga (UNAM),
Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report:
We again observed the field of GRB 141004A (D'Elia, et al., GCN 16878)
with the Reionization and Transients Infrared Camera (RATIR;
www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio
Astron��mico Nacional on Sierra San Pedro M��rtir from 2014/10 31.31 to
2014/10 31.46 UTC (26.34 to 26.48 days after the BAT trigger), obtaining
a total of 2.84 hours exposure in the r, i and z bands.
We continue to detect the source reported from previous epochs of RATIR
observations (Littlejohns, et al., GCN 16963; GCN 16937; GCN 16887). We
obtain the following detections and upper limit (3 sigma):
r 23.62 +/- 0.19
i 23.17 +/- 0.15
z > 21.09
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB. In comparison to our previous
epochs of observations, the source appears to have brightened in the r
and i bands, consistent with an emerging supernova similar to SN 1998bw
(Schulze, et al., GCN 16936).
We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
M��rtir.