GRB 140226A
GCN Circular 16037
Subject
GRB 140226A/iPTF14yb: Mondy optical observations
Date
2014-03-25T15:11:32Z (11 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A.Volnova (IKI), A. Pozanenko (IKI), I. Korobtsev (ISTP), E. Klunko
(ISTP), M. Eselevich (ISTP), report on behalf of larger GRB follow-up
collaboration:
We observed the field of transient iPTF14yb (Cenko et al., GCN 15883,
Beardmore et al., GCN 15884, 15891) a possible counterpart of GRB
140226A (Hurley et al., GCN 15888) with AZT-33IK telescope of Mondy
observatory on Feb. 28 between (UT) 19:22:46 - 21:52:52 R-filter. On a
stacked image of 75 x 120 s we clearly detected iPTF14yb source with a
magnitude of R = 22.86 �� 0.17 at Feb. 28.85959 (mid) or 2.44087 days
after GRB 140226A trigger (Hurley et al., GCN 15888).
The photometry is based on SDSS J144600.66+145826.2 star assuming
R(Lupton transformation)= 17.624 +/- 0.018.
GCN Circular 15895
Subject
GRB 140226A/iPTF14yb: 1.23m CAHA observations
Date
2014-03-01T07:09:10Z (12 years ago)
From
Javier Gorosabel at IAA-CSIC <jgu@iaa.es>
J. Gorosabel (IAA-CSIC/UPV-EHU), A. Sanchez-Lavega, I. Ordonez, S. Perez-Hoyos, R. Hueso (UPV/EHU), J.J. Salamero, D. Cebrian, P. Martorell, R. Pidal (Obs. Guirguillano), report on behalf of the BEGIRA project:
"We carried out optical observations of the GRB140226A/iPTF14yb transient field (Cenko et al., GCN 15883, Beardmore et al., GCN 15884, 15891) with the 1.23m CAHA telescope. The observations were performed in the R-band on Feb 28.14668-28.19763 UT. The object is detected with a Vega magnitude of R~23 calibrated against the USNO-B1.0 catalog."
[GCN OPS NOTE(04mar14): Per author's request, A.S-L was added to the author list.]
GCN Circular 15894
Subject
GRB 140226A/iPTF14yb: Swift/UVOT Observations
Date
2014-02-28T16:39:17Z (12 years ago)
From
Mike Siegel at PSU/Swift MOC <siegel@swift.psu.edu>
M. H. Siegel (PSU), F. E. Marshall (NASA/GSFC) and A. P. Beardmore (U. Leicester)
report on behalf of the Swift/UVOT team:
Swift/UVOT started observations of GRB140226A/iPTF14yb (Cenko et al., GCN Circ.
15833) 25718 s after the IPN trigger (Hurley et al., GCN Circ. 15888).
No optical counterpart is detected at the position of the iPTF or
XRT positions (Beardmore et al., GCN Circ 15884) in summed
exposures.
Preliminary 3-sigma upper limit using the UVOT photometric system
(Breeveld et al al. 2011, AIP Conf. Proc. 1358, 373) is:
Filter T_start (s) T_stop (s) Exp(s) Mag
uvm2 25718 43672 2180 >21.24
v 124093 136265 4877 >20.96
v 147705 154552 1822 >20.54
No correction has been made for the expected Galactic extinction
corresponding to E(B-V) = 0.02 in the direction of the burst (Schlegel et al. 1998).
GCN Circular 15893
Subject
GRB 140226A/iPTF14yb: Mondy optical observations
Date
2014-02-28T16:22:51Z (12 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A.Volnova (IKI), A. Pozanenko (IKI), I. Korobtsev (ISTP), E. Klunko
(ISTP), M. Eselevich (ISTP), report on behalf of larger GRB follow-up
collaboration:
We observed the field of transient iPTF14yb (Cenko et al., GCN 15883,
Beardmore et al., GCN 15884, 15891) of possible GRB 140226A (Hurley et
al., GCN 15888) with AZT-33IK telescope of Mondy observatory on Feb. 27
between (UT) 18:59:34 - 19:59:36. On a stacked R-filter image of 30 x
120 s we marginally detected iPTF14yb source with S/N ~2, and
photometry of the source R = 23.0 at Feb. 27.81221 (mid).
The photometry is based on SDSS J144600.66+145826.2 star assuming
R(Lupton transformation)= 17.624 +/- 0.018
GCN Circular 15892
Subject
GRB 140226A/iPTF14yb: RATIR Optical and NIR Observations
Date
2014-02-28T15:47:46Z (12 years ago)
Edited On
2024-11-07T19:49:32Z (10 months ago)
From
Antonino Cucchiara at NASA/GSFC <antonino.cucchiara@nasa.gov>
Edited By
Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@nasa.gov> on behalf of Leo P. Singer at NASA/GSFC <leo.p.singer@nasa.gov>
Antonino Cucchiara (ORAU/GSFC),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),
Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC),
José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM),
Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report:
We observed again the field of the GRB-like transient iPTF14yb (Cenko et al., GCN 15883,
Beardmore et al., GCN 15884, 15891) with the Reionization and Transients Infrared Camera
(RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico
Nacional on Sierra San Pedro Mártir from 2014/02 28.34 to 2014/02 28.53 UTC (roughly 46
to 50 hours after the reported time of discovery), obtaining a total of 2.63 hours exposure
in the r and i bands and 1.12 hours exposure in the Z and J bands.
For the source within the Cenko et al. (GCN 15883) error circle, in comparison with the
SDSS DR9 and 2MASS, we obtain the following detections and upper limits:
r 23.28 +/- 0.32
i 22.51 +/- 0.20
Z > 22.11
J > 21.73
The detections are at the 2-sigma level and the upper limits at the 3-sigma level.
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.
Our photometry indicates that the transient is still fading in r band with a similar
decay index (within the systematic errors) as reported by Cucchiara et al. (GCN
15886).
We thank the staff of the Observatorio Astronómico Nacional in San Pedro
Mártir.
[GCN OPS NOTE(28feb14): Per author's reuqest, the Y & H bands were removed
from the last sentence in the first paragraph.]
GCN Circular 15891
Subject
GRB 140226A / iPTF14yb: Swift-XRT confirms a fading X-ray source
Date
2014-02-28T15:11:10Z (12 years ago)
From
Andy Beardmore at U Leicester <ab271@leicester.ac.uk>
A.P. Beardmore (U. Leicester) reports on behalf of the Swift-XRT team:
The Swift-XRT has continued to observe the source GRB 140226A /
iPTF14yb (Cenko et al., GCN Circ. 15883; Cucchiara et al., GCN
Circ. 15886; Varela et al., GCN Circ. 15887; Hurley et al., GCN
Circ. 15888) and has now accumulated 9.1ks of data in Photon Counting
(PC) mode. The X-ray light curve shows that the source announced by
Beardmore et al. (GCN Circ. 15884) has faded, with a powerlaw decay
index of 1.47 +0.29 -0.25 (with respect to the Konus-Wind T0;
Golenetskii et al., GCN Circ. 15889).
Taken together with the fading optical source and IPN localisation,
the decaying X-ray source confirms the GRB origin of the object.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00033157.
GCN Circular 15889
Subject
Konus-Wind observation of GRB 140226A
Date
2014-02-28T08:16:29Z (12 years ago)
From
Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>
S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin,
P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf
of the Konus-Wind team, report:
The long-duration GRB 140226A
(IPN trangulation: Hurley et al., GCN 15888),
which is a possible counterpart to the optical
transient source iPTF14yb (Cenko et al. GCN 15883),
was detected by Konus-Wind in the waiting mode
against the high solar particle background.
The light curve shows a single pulse, which peaked
at T0=36177 s UT (10:02:57) and had a duration of ~15 s.
As observed by Konus-Wind, the burst had a fluence of
(5.6 � 1.1)x10^-6 erg/cm2 and a 2.944-s peak energy flux,
measured from T0 of (8.6 � 1.7)x10^-7 erg/cm2
(both in the 20 - 10000 keV energy range).
Modeling the KW 3-channel time-integrated spectrum
(from T0-6.263 s to T0+5.513 s) by a power law
with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = -1.1 � 0.1, and Ep = 414 � 79 keV.
All the quoted errors are estimated at 1 sigma confidence level.
All the presented results are preliminary.
The K-W light curve of this burst is available at
http://www.ioffe.rssi.ru/LEA/GRBs/GRB140226A/
GCN Circular 15888
Subject
IPN triangulation of GRB 140226A, a possible GRB counterpart to iPTF14yb
Date
2014-02-28T00:25:44Z (12 years ago)
From
Kevin Hurley at UCBerkeley/SSL <khurley@ssl.berkeley.edu>
K. Hurley, on behalf of the Interplanetary Network,
S. Golenetskii, R. Aptekar, V. Pal'shin, D. Frederiks,
D. Svinkin, and T. Cline on behalf of the Konus-Wind team,
I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin,
on behalf of the HEND-Odyssey GRB team,
W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr, on
behalf of the GRS-Odyssey GRB team,
A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C.
Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,
S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer, on behalf of
the Swift-BAT team, and
V. Connaughton, M. S. Briggs, C. Meegan, and V. Pelassa, on behalf of the Fermi
GBM team, report:
We have examined IPN data for the period 2014-02-26T09:05:00 to
2014-02-26T10:18:00, when the optical transient source iPTF14yb was
discovered (Cenko et al. GCN 15883). During this time, Konus, Swift,
INTEGRAL, RHESSI, Odyssey, and MESSENGER were operating and returning
data, although in the presence of increased solar activity. Suzaku was
off. We have identified one event, at 2014-02-26T10:02:57 (36177 s),
observed by Odyssey, INTEGRAL (SPI-ACS) and Konus (in the waiting
mode), whose duration is ~15 s, and whose localization is consistent
with iPTF14yb. Specifically, the Odyssey-INTEGRAL triangulation
annulus is centered at RA, Dec = 206.305 degrees (13 h 45 m 13.2 s),
-7.925 degrees (-7 o 55 ' 29 "), with radius 27.577 +/- 0.607 degrees
(3 sigma). iPTF14yb lies 0.157 degrees from the center line of the
annulus. The probability that the transient lies within the annulus by
chance is roughly 0.005. At the time of this event, the optical
transient was below the horizon for Swift, and no emission consistent
with a GRB was seen in the data. Fermi was in the SAA. The RHESSI and
MESSENGER backgrounds were high and variable due to solar activity,
making the identification of this burst uncertain in their data.
If this is indeed the GRB counterpart to iPTF14yb, this would appear to
be the first GRB to be discovered on the basis of its optical
counterpart.
This triangulation can be improved. Detailed spectral and temporal
information on this burst will be presented in a forthcoming GCN
Circular.