J/ApJ/678/1127 Optical photometry of GRB 070610 (Kasliwal+, 2008)
GRB 070610: a curious galactic transient.
Kasliwal M.M., Cenko S.B., Kulkarni S.R., Cameron P.B., Nakar E.,
Ofek E.O., Rau A., Soderberg A.M., Campana S., Bloom J.S., Perley D.A.,
Pollack L.K., Barthelmy S., Cummings J., Gehrels N., Krimm H.A.,
Markwardt C.B., Sato G., Chandra P., Frail D., Fox D.B., Price P.A.,
Berger E., Grebenev S.A., Krivonos R.A., Sunyaev R.A.
<Astrophys. J., 678, 1127-1135 (2008)>
=2008ApJ...678.1127K 2008ApJ...678.1127K
ADC_Keywords: Gamma rays ; Magnitudes ; X-ray sources
Keywords: gamma rays: bursts - stars: flare - X-rays: binaries -
X-rays: bursts - X-rays: individual (Swift J195509.6+261406)
Abstract:
GRB 070610 is a typical high-energy event with a duration of 5s. Yet
within the burst localization we detect a highly unusual X-ray and
optical transient, Swift J195509.6+261406. We see high-amplitude X-ray
and optical variability on very short timescales even at late times.
Using near-infrared imaging assisted by a laser guide star and
adaptive optics, we identified the counterpart of Swift
J195509.6+261406. Late-time optical and near-infrared imaging
constrain the spectral type of the counterpart to be fainter than a
K-dwarf, assuming it is of Galactic origin. It is possible that GRB
070610 and Swift J195509.6+261406 are unrelated sources. However, the
absence of a typical X-ray afterglow from GRB 070610 in conjunction
with the spatial and temporal coincidence of the two motivate us to
suggest that the sources are related. The closest (imperfect) analog
to Swift J195509.6+261406 is V4641 Sgr, an unusual black hole binary.
We suggest that Swift J195509.6+261406 along with V4641 Sgr define a
subclass of stellar black hole binaries-the fast X-ray novae. We
further suggest that fast X-ray novae are associated with bursts of
gamma rays. If so, GRB 070610 defines a new class of celestial
gamma-ray bursts and these bursts dominate the long-duration GRB
demographics.
Description:
We monitored the field of Swift J195509.6+261406 in the i' filter with
the automated Palomar 60 inch telescope starting at 5:47 UT 2007 June
12 and continued over the next several nights.
Objects:
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RA (2000) DE Designation(s)
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19 55 09.6 +26 14 07 SWIFT J195509.6+261406 = GRB 070610
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 47 301 Optical observations of Swift J195509.6+261406
with Palomar 60-inch telescope
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 A4 month ObsMonth Month of observation start; 2007 UT
6- 12 F7.4 d ObsDay Day of observation start; 2007 UT
14- 16 A3 --- Tel Telescope used: P60 = Palomar 60-inch
18- 19 A2 --- Filter [i'] Filter used = i' band
21- 26 F6.2 h Time Time since burst detection
28- 35 A8 s Exp Exposure time (x number of exposures)
37 A1 --- l_i'mag Upper 3σ limit flag on mag
39- 42 F4.1 mag i'mag Observed AB magnitude in Filter (1)
44- 47 F4.2 mag e_i'mag ? The 1σ error in mag (2)
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Note (1): Zeropoint computed in the AB system. No correction has been made for
the large line-of-sight extinction.
Note (2): Photometric and instrumental errors summed in quadrature. Note that
the uncertainty in the zeropoint estimate (relative to USNO-B stars)
dominates but is an overestimate for variability studies using
relative magnitude.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 21-Sep-2010