GRB 090817
GCN Circular 9842
Subject
GRB 090817 - TLS Observations
Date
2009-08-27T00:27:50Z (16 years ago)
From
Alexander Kann at TLS Tautenburg <kann@tls-tautenburg.de>
D. A. Kann, F. Cusano and F. Ludwig (TLS Tautenburg) report:
We observed the field of the INTEGRAL/Fermi GRB 090817 (Beckmann et al.,
GCN 9815, Wilson-Hodge, GCN 9823) with the 1.34m Tautenburg Schmidt
telescope under good conditions. We obtained 3 x 600 sec Rc images at a
mid-time of 8.015 days after the GRB.
At the position of the X-ray afterglow (Evans, Guidorzi & Baumgartner,
GCN 9819, GCN 9825), the USNO-B1.0 object 1341-0096763 is clearly
detected. Using the comparison star of Rumyantsev, Pozanenko & Andreev
(GCN 9828), we find Rc = 19.54 +/- 0.03 mag. This is in agreement
with the reports of non-variability (Rumyantsev, Pozanenko & Andreev,
GCN 9828, Halpern & Ruan, GCN 9837) of this proposed host galaxy/SN
candidate (Holland, Breeveld & Baumgartner, GCN 9831, GCN 9834), and a
stellar PSF is in full agreement with it being a foreground star (Halpern
& Ruan, GCN 9837, Cenko et al., GCN 9841).
No further observations are planned.
This message may be cited.
GCN Circular 9841
Subject
GRB090817: Keck/LRIS Spectroscopy
Date
2009-08-26T08:22:47Z (16 years ago)
From
S. Bradley Cenko at Caltech <cenko@srl.caltech.edu>
S. B. Cenko, L. M. Walkowicz (UC Berkeley), M. M. Kasliwal, V. Bhalero, S.
R. Kulkarni, F. A. Harrison (Caltech), I. Arcavi (Weizmann Institute) and
W. H. Baumgartner (GSFC/UMBC) report on behalf of a larger collaboration:
We have obtained a spectrum of the putative host galaxy of GRB09817
(Holland et al., GCNs 9831 and 9834) with the Low Resolution Imaging
Spectrometer mounted on the 10 m Keck I telescope. Our spectra were taken
in twilight conditions at Aug 25.55 UT and cover a wavelength range from
3500 - 9000 A.
After correcting for the large Galactic extinction, the source exhibits
a blue continuum with superposed absorption features from the H Balmer
series (H-alpha, -beta, -gamma, and -delta) and Ca (H+K and the NIR
triplet), all consistent with their rest wavelengths. As suggested by
Halpern and Ruan (GCN 9837), the object is therefore a foreground star
(likely a hot, ~ A-type) and likely unrelated to GRB090817.
GCN Circular 9837
Subject
GRB 090817: No host galaxy, no supernova
Date
2009-08-25T11:16:13Z (16 years ago)
From
Jules Halpern at Columbia U. <jules@astro.columbia.edu>
J. P. Halpern and J. Ruan (Columbia U.) report:
We obtained R-band photometry of the USNO-B1.0 object 341-0096763
on 2009 August 21 10:46 UT using the McGraw Hill 1.3m telescope.
In five 300 s exposures in seeing of 1.5"-1.8", there is no evidence
to support the hypothesis of Holland et al. (GCN Circ. 9831) that this
object is the host galaxy of GRB 090817. The image is consistent
with the stellar point spread function. Using the reference star of
Rumyantsev et al. (GCN Circ. 9828), we measure R = 19.39+/-0.04,
consistent with their photometry on Aug. 17.
On Aug. 25 09:56 UT, we again obtained five 300 s exposures in seeing
of 1.5". We measure R = 19.42+/-0.03, 8.4 days after the burst,
which is consistent with all previous measurements. Thus, there is
no evidence for brightening suggested by Holland et al. (GCN Circ. 9834)
from Swift UVOT observations between 6.5 and 7.1 days. The set of
consistent magnitudes from day zero in GCN Circ. 9828 to days 4 and 8
in this report are indicative of a chance coincidence with a normal star.
GCN Circular 9834
Subject
GRB 090817: Swift/UVOT Observations of a Possible Late-Time Brightening
Date
2009-08-24T18:58:29Z (16 years ago)
From
Stephen Holland at USRA/NASA/GSFC/SSC <Stephen.T.Holland@nasa.gov>
S. T. Holland (CRESST/GSFC/USRA), A. Breeveld (MSSL/UCL), and
W. Baumgartner (GSFC/UMBC) report on behalf of the Swift UVOT team:
Swift/UVOT observed the USNO-B1.0 source 1341-0096763 (Evans et
al. 2009, GCN Circ. 9819; Rumyantsev et al. 2009, GCN Circ. 9828;
Holland et al. 2009, GCN Circ. 9831), which is located inside the XRT
error circle (Evans et al., 2009, GCN Circ. 9819), at approximately 6
and 7 days after the INTEGRAL trigger (Beckman et al., 2009, GCN
Circ. 9815). A preliminary examination of the UVOT data yields weak
evidence that the source may have brightened by approximately 0.5 mag
in the UVOT v band between approximately 6.5 and 7.1 days. Our
observations are consistent with a supernova rising to maximum light.
However, we stress that further observations are needed to confirm
this. Follow-up photometric and spectroscopic observations of this
source are strongly encouraged.
GCN Circular 9831
Subject
GRB 090817: Swift/UVOT Observations of a Host Galaxy Candidate
Date
2009-08-20T19:17:42Z (16 years ago)
From
Stephen Holland at USRA/NASA/GSFC/SSC <Stephen.T.Holland@nasa.gov>
S. T. Holland (CRESST/GSFC/USRA), A. Breeveld (MSSL/UCL), and
W. Baumgartner (GSFC/UMBC) report on behalf of the Swift UVOT team:
The Swift/UVOT observed the field of GRB 090817 (Beckman et al.,
2009, GCN Circ. 9815) between 11 ks and 284 ks after the INTEGRAL
trigger. The USNO-B1.0 source 1341-0096763 (Evans et al. 2009, GCN
Circ. 9819