GRB 090410

D. Grupe (PSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
M. M. Chester (PSU), J. R. Cummings (NASA/UMBC),
N. Gehrels (NASA/GSFC), S. T. Holland (CRESST/USRA/GSFC),
J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA),
N. P. M. Kuin (MSSL), K. L. Page (U Leicester), D. M. Palmer (LANL),
J. L. Racusin (PSU), M. H. Siegel (PSU), M. Stamatikos (NASA/ORAU),
M. C. Stroh (PSU) and T. N. Ukwatta (GSFC/GWU) report on behalf of
the Swift Team:

At 16:57:52 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 090410 (trigger=348929).  Swift could not slew to the GRB
due to a Sun constraint. The BAT on-board calculated location is 
RA, Dec 334.980, +15.471 which is 
   RA(J2000) = 22h 19m 55s
   Dec(J2000) = +15d 28' 16"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex peak
from T-10 to T+40, followed by another broad peak from T+80 to T+140. 
The peak count rate was ~6000 counts/sec (15-350 keV), at ~6 
sec after the trigger. 

Swift cannot slew to the BAT position.  The burst is  sun-constrained
until Tuesday, 2009 April 14.  There will thus be no XRT or UVOT 
data for this trigger. 

Burst Advocate for this burst is D. Grupe (grupe AT astro.psu.edu). 
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.)

S.D. Barthelmy (GSFC), W.H. Baumgartner (GSFC/UMBC), J.R. Cummings (GSFC/UMBC),
E.E. Fenimore (LANL), N. Gehrels (GSFC), D. Grupe (PSU),
H.A. Krimm (GSFC/USRA), C.B. Markwardt (GSFC/UMD), D.M. Palmer (LANL),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data sets from T-240 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 090410 (trigger #348929)
(Grupe, et al., GCN Circ. 9122
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 ).  The BAT ground-calculated position is
RA, Dec = 334.956, 15.419 deg, which is 
   RA(J2000)  =  22h 19m 49.4s 
   Dec(J2000) = +15d 25' 08.6" 
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
 
The mask-weighted light curve shows two main peaks with some precursor activity.
The precursor activity starts at ~T-55 sec.  And because the target location
only came into the BAT FOV at T-110 sec, there may have been even earlier activity.
The first main peak started at ~T-10 sec, peaked at ~T+7 sec, and ended 
around T+45 sec.  The second main peak started at ~T+80 sec, peaked at ~T+120 sec,
and returned to baseline T+170 sec.  The burst location left the BAT FOV
at ~T+390 sec.  T90 (15-350 keV) is 165 +- 8 sec (estimated error
including systematics).
 
The time-averaged spectrum from T-49.2 to T+139.4 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.19 +- 0.05.  The fluence in the 15-150 keV band is 5.6 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+8.90 sec in the 15-150 keV band
is 1.9 +- 0.1 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/348929/BA/

M. Yoshida, D. Kuroda, K. Yanagisawa, Y. Shimizu, S. Nagayama,
H. Toda (OAO, NAOJ) and N. Kawai (Tokyo Tech) report on behalf
of the MITSuME collaboration:

We observed the field of GRB 090410 (Grupe et al. GCN 9122
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 ;
Barthelmy et al. GCN 9123
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 ) with optical three color (g', Rc and
Ic) CCD camera attached to the MITSuME 50cm telescope of Okayama
Astrophysical Observatory. We started the observation at 18:12:59
UT, 4507s after the alert. We did not detect any new point source
within the BAT error circle (Barthelmy et al. GCN 9123
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 ). 3-sigma
upper limits to our observation are listed below. We used GSC2.3
catalog for flux calibration.

       Mid-UT           Td       EXP-T      g'     Rc    Ic
-------------------------------------------------------------
2009-04-10 18:57:15   7163sec   72x60sec  >17.9  >18.1  >18.5
-------------------------------------------------------------

P. Afonso, T. Kruehler, A. Rau and J. Greiner (MPE Garching), report on 
behalf of the GROND team:

GROND (Greiner et al. 2008, PASP 120, 405), the 7-channel imager mounted at 
the 2.2m ESO/MPI telescope at La Silla Observatory (Chile) started 
follow-up observations of GRB 090410 (Grupe et al. 2009, GCN #9122
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 ) on April 
11, at 10:17 UTC (17.3 h after the burst). In addition, a second epoch of 
imaging was obtained, which started on April 12, 10:10 UTC.

Observations were performed at high airmass (~2.5) and limited to a total 
of 4 min exposures in each J, H and K in both epochs because of Sun 
constraints.

We do not detect any new object with respect to 2MASS inside the enhanced 
BAT error circle (Barthelmy et al. 2009, GCN #9123
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 ), and image subtraction 
between the two epochs does not reveal any obvious variable source. Upper 
limits from the first observation are as follows (all in the AB system):

J > 19.1 mag
H > 19.0 mag
K > 18.1 mag

The upper limits have been obtained using 2MASS field stars as reference. 
The given magnitudes are not corrected for the expected Galactic foreground 
extinction of E(B-V) of 0.05 mag.

W. Iwakiri, M. Tashiro, Y. Terada, A. Endo, K. Onda,
T. Sugasahara (Saitama U.), Y. Urata (NCU),
M. Ohno, M. Suzuki, M. Kokubun, T. Takahashi (ISAS/JAXA),
T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo),
K. Yamaoka, S. Sugita (Aoyama Gakuin U.), Y. E. Nakagawa, T. Tamagawa
(RIKEN),
T. Uehara, T. Takahashi, Y. Fukazawa, Y. Hanabata (Hiroshima U.),
E. Sonoda, M. Yamauchi, N. Ohmori, K. Kono, H. Hayashi (Univ. of
Miyazaki),
S. Hong (Nihon U.), N. Vasquez (Tokyo Tech.),
on behalf of the Suzaku WAM team, report:


The long GRB 090410 (Swift/BATtrigger #348929 ; Grupe et al.,
GCN 9122
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 ) triggered the Suzaku Wide-band  All-sky Monitor (WAM)
 which covers an energy range of 50 keV - 5 MeV at 16:57:53.392 UT
(=T0).

The observed light curve shows  main peaks starting at T0-5s, ending
at T0+25s, followed by a long weak tail seen up to T0+150s. And the
precursor activity reported by Swift/BAT (Barthelmy et al., GCN 9123
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 )
is also seen at T0-55s. The total T90 duration including this precursor
is about 166 seconds. The fluence in 100 - 1000 keV was 1.2 +/- 0.3  x
10^-5 erg/cm^2. The 1-s scaled peak flux measured from T0+5s was 3.0
(-0.3, +0.2)
photons/cm^2/s in the same energy range.

Preliminary result shows that the time-averaged spectrum from T0-60s to
T0+150s is well fitted by a single power-law with a photon index
of 2.3 (-0.3, +0.3) (chi^2/d.o.f = 4.9/8), and the spectrum of the main
bright peak from T0-5s to T0+25s is well fitted by a power-law with
exponential cutoff model:
 dN/dE ~  E^{-alpha} * exp(-(2-alpha)*E/Epeak) with
 alpha       1.3 +/-0.5, and
 Epeak       304 (-79, +60) keV (chi^2/d.o.f. = 7.9/7).

All the quoted errors are at statistical 90% confidence level,
in which the systematic uncertainties are not included.

The light curves for this burst are available at:

 http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html

K.Kinugasa et al. (Gunma Astronomical Observatory);

I also made a typo in GCN 9189
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 . We observed "GRB 090410 (Grupe et al.
GCN 9122
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 )" instead of "GRB 080410" in subject.
I apologize for my carelessness.