GRB 080229A, GRB 080229

Aquib Moin (Curtin Institute of Radio Astronomy / Australia Telescope
National Facility), Steven Tingay (Curtin Institute of Radio Astronomy),
Chris Phillips (Australia Telescope National Facility), Gregory Taylor
(University of New Mexico), Mark Wieringa (Australia Telescope National
Facility) and Ralph Martin (Perth Observatory) report:

We observed the BAT refined position of the GRB 080229a (GCN 7338
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 ) at
4.8 and 8.456 GHz with the Australia Telescope Compact Array (ATCA) on
May 31, 2008 between 08:18:55 UT and 13:38:25 UT.

We did not detect a radio source at the BAT position of the GRB 080229a
(GCN 7338
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 ). The radio flux density at the GRB position is -0.053 +/-
0.175 mJy at 4.8 GHz, and -0.383 +/- 0.356 mJy at 8.6 GHz (1-sigma).

The Australia Telescope Compact Array (/ Parkes telescope / Mopra
telescope / Long Baseline Array) is part of the Australia Telescope
which is funded by the Commonwealth of Australia for operation as a
National Facility managed by CSIRO.

See field image at:

http://cira.ivec.org/dokuwiki/doku.php/grb/grb_080229a_field_image 

Please note: http://astronomy.ivec.org is now http://cira.ivec.org

K. Kinugasa (Gunma Astronomical Observatory)  report:

 The field of GRB 080229A (Cannizzo et al. GCN 7335
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 ) was observed
with the 150 cm telescope of the Gunma Astronomical Observatory.
Starting at 18:19 UT (1.25 hours after the burst), Rc, and Ic frames
were acquired for 5 x 3-min exposures  under a poor seeing (~3.5arcsec)
condition.

 The enhaunced XRT position (Beardmore et al. GCN 7343
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 ) is close to 
a bright star, so the field are strongly contaminated  with the light 
from this star. We do not identify the optical counterpart reported
by Yoshida et al. (GCN 7341
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 ) to 3-sigma limiting magnitudes of Rc=19.3
and Ic=18.7 relative to USNO-B1.0 magnitudes.

T. Minezaki (IoA, Tokyo), P.A. Price (IfA, Hawaii), Y. Yoshii (IoA,
Tokyo), L. Cowie (IfA, Hawaii) and Y. Kakazu (IfA, Hawaii) report:

We observed the localisation of GRB 080229 with the MAGNUM telescope +
MIP dual-beam imager. We do not find any afterglow in the RIYJHK images
within the XRT error circle (GCN #7343
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 ). We estimated the upper limits
in JHK based on flux calibration with a nearby 2MASS star as follows:

  Filter   t - t_GRB (hour)    Limit (mag)
  J        +19.8               20.5
  H        +20.7               20.0
  K        +20.4               19.4

This message may be cited.

R.Hara notes:

I stated in GCN7337
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 $B!!(Bas
"The observation was started 17:05:03 UT, ~225 min
after the Swift trigger time."

but the correct one is
"The observation was started 19:30:40 UT, about 146 min
after the Swift trigger time."

We apologize for any inconvenience this may have caused.

R. Hara, H.hayasi, N.Ohmori, K.Kono H. Tanaka, M.Yamauchi, E.Sonoda,
(University of Miyazaki)

We have observed the field covering the error circle of
GRB080229 (GCN 7338
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 , C. Markwardt et al.) with
the unfiltered CCD camera on the 30-cm telescope at
University of Miyazaki.
The observation was started 17:05:03 UT, ~225 min
after the Swift trigger time.

We have compared our data of 30 sec exposures
with the USNO-A2.0 catalog,there is no new source
at the reported position.

the upper limits are as follows:
--------------------------------------------------------------
Start(UT) End(UT)	Num. of frames 	Limit (mag.)
--------------------------------------------------------------
19:33:57 19:34:27 	1 		~16.06
19:33:57 20:39:37 	20 		~16.79
---------------------------------------------------------------

Poonam Chandra (NRAO/UVA) and Dale A. Frail (NRAO) report on
behalf of the Caltech-NRAO-Carnegie GRB Collaboration:


"We used the Very Large Array to observe the field of view toward
GRB 080229 (GCN 7335
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 ) at a frequency of 8.46 GHz on 2008 March
01.50 UT. We detect a radio source of flux density of 635 +/- 44
uJy at a position of
RA(J2000) 15 12 52.21984, DEC(J2000) -14 42 15.3000.
This is 2.82" away from the X-ray afterglow position determined by
Swift-XRT (GCN 7343
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 ).

The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc."

A. de Ugarte Postigo (ESO, Chile), F. Aceituno,
A.J. Castro-Tirado (IAA-CSIC, Spain) on behalf
of a larger colaboration report,

We have observed the field of GRB 080229 (Cannizzo et al. GCN 7335
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 )
with the 1.5m telescope at Sierra Nevada Observatory (OSN, Granada).
The observations were obtained in I-band and range between March
1.1681 and March 1.2638 UT (mean exposure 0.5042 days after the burst).
We do not detect any new source in the error box of Swift/XRT
(Beardmore et al. GCN 7343
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 ) down to a 3-sigma limiting magnitude of
I~22.0.

This message can be cited.

P. D'Avanzo and G. Tagliaferri (INAF-OAB) on behalf of the MISTICI 
collaboration report:

We observed the field of the GRB 080229 (Cannizzo et al., GCN 7335
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 ) with 
the ESO-VLT on March 01.411 UT (about 16.8 hours after the burst). 
Observations have been carried out in J-band with the ISAAC NIR camera 
in imaging mode under very good (0.7") seeing conditions.

We do not detect any afterglow candidate inside the enhanced XRT error 
box (Beardmore et al., GCN 7343
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 ) down to J > 21.6 (3sigma c.l., 
calibrated against the 2MASS catalog).

We acknowledge support from the ESO staff, in particular Thomas Szeifert.

GRB080229: Swift XRT refined analysis

J.Mao, (INAF-OAB), A. Moretti (INAF-OAB), J. Canizzo (NASA/UMBC), C. 
Guidorzi
(Univ. Bicocca & INAF-OAB), A, Beardmore (U Leicester)
P. Evans (U Leicester) report on behalf of the Swift-XRT team:

We have analysed the first 2 orbits of Swift-XRT data obtained for
BAT GRB 080229 (trigger #304379, Cannizzo, et al., GCN Circ. 7335
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 ).

The data consist of 149 s in Windowed Timing (WT) mode, starting 90 s
after the BAT trigger and 8.34 ks in Photon Counting (PC) mode.
The astrometrically corrected X-ray position is given  in Beardomre et 
al. GCN 7324
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 .

The XRT light-curve shows a flare peaking few seconds after the beginning
of the observation (103+/-2 s). The descending part of the flare can be 
fit by a power law with
a slope of alpha1=4.45+/-0.09 up to a break at t1=192.4+/- 2.5 s, which is
followed by a flat decay with a slope of alpha2=0.18+/-0.01.
A second break is present at 2700+/-1000 s with alpha3=0.8+/-0.5

The spectrum formed from all the WT data can be modeled with a
power-law of photon index Gamma = 2.88 � 0.09, with an absorbing
column of NH = (3.1 � 0.2)e21 cm^-2 (in excess with respect to the
Galactic value of 8.97e20 cm^-2). The spectrum formed from the PC data
can be modeled with a power-law of photon index Gamma = 1.99 �
0.07, with an absorbing column of NH = (3.1 � 0.2)e21 cm^-2, which
is in agreement with the WT one.

If the light-curve continues to decay with a slope of 0.8, the
afterglow at 24 hour will be still bright with an expected count
rate of 0.3 count s^-1. This corresponds to an observed (unabsorbed) flux
of 1.41E-11(2.2e-11) erg cm-2 s-1.

This circular is an official product of the Swift-XRT team.

P. D'Avanzo, C. Guidorzi (INAF-OAB) on behalf of the CIBO collaboration 
and G. Andreuzzi and Noemi Pinilla Alonso (FGG-INAF, TNG) report:

We observed the field of the GRB 080229 (Cannizzo et al., GCN 7335
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 ) with 
the Italian 3.6m TNG telescope located at Canary Islands on March 01.259 
UT (about 13.1 hours after the burst). Observations have been carried 
out with the NICS NIR camera in imaging mode under good (1.1") seeing 
conditions.

We do not detect any afterglow candidate inside the enhanced XRT error 
box (Beardmore et al., GCN 7343
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 ) down to the following limiting 
magnitudes (3sigma c.l., calibrated against the 2MASS catalog):

J > 20.9
H > 20.1
K > 19.5

E. Berger (Princeton/Carnegie) reports on behalf of a larger 
collaboration:

"We observed the refined BAT error circle of GRB 080229 (GCN #7338
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 ) with 
GMOS on the Gemini-South telescope starting on 2008 Mar 1.26 UT (13.1 
hours after the burst).  We obtained a total of 5x120 sec in g,r,i,z is 
0.8" seeing.  We do not detect any sources within the XRT error circle 
(GCN #7343
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 ) to the following 3-sigma magnitude limits: g>26.0, r>25.9, 
i>25.6, z>25.3."

A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 1276 s of overlapping XRT Photon Counting mode and UVOT
V-band data for GRB 080229, 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 = 228.21828, -14.70467 which is equivalent
to:

RA (J2000): 15h 12m 52.39s
Dec (J2000): -14d 42' 16.8"

with an uncertainty of 1.4 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
http://www.swift.ac.uk/xrt_positions/Goad.pdf).

This circular was automatically generated, and is an official product of the
Swift-XRT team.

P. D'Avanzo, L.A. Antonelli, S. Covino, D. Fugazza, L.  Calzoletti, S. 
Campana, G.  Chincarini, M.L. Conciatore, S. Cutini, V. D'Elia, F. 
D'Alessio, F.  Fiore, P. Goldoni, D. Guetta,  C. Guidorzi, G.L. Israel, 
E. Maiorano, N. Masetti, A. Melandri, E. Meurs, L. Nicastro, E. Palazzi, 
E. Pian, S. Piranomonte, L.  Stella, G.  Stratta, G. Tagliaferri, G. 
Tosti, V.Testa, S.D. Vergani,  F. Vitali report on behalf of the REM team:

The robotic 60-cm REM telescope located at La Silla (Chile) observed 
automatically the field of the GRB 080229 (Cannizzo et al., GCN 7335
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 ) on 
March 01.154 UT (about 10.6 hours after the burst).

We do not detect any afterglow candidate inside the XRT error box down 
to the following limiting magnitudes (3sigma c.l., calibrated against 
the 2MASS catalog):

J > 16.3
H > 15.6
K > 14.4

Further analysis is in progress.

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

We performed optical imaging observations (g', Rc, and Ic) of the
field of GRB 080229 (Cannizzo et al. GCN 7335
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 ) with 50cm MITSuME
telescope at Okayama Astrophysical Observatory from UT 17:06:55
(117sec after the trigger) to UT 17:24:40 on Feb 29 2008.

We found a faint fading source in the XRT error circle (Cannizzo
et al: GCN 7335
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 ) only in the Ic band. There was no source in the
g' and the Rc bands. Together with the UVOT results (Kuin and
Cannizzo GCN7339
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 ), this may suggest that this GRB is a high-
redshift one. Follow-up observations in infrared bands are
encouraged.

The magnitude of the fading source and 3-sigma upper limits are
summarized below.

Observation date  2008-02-29 UT

mid-UT    exp-T      g'      Rc       Ic
---------------------------------------------
17:09:40   5 min   >17.5   >17.8    17.1+-0.3
17:18:58  11 min   >17.6   >18.2    >18.0
---------------------------------------------

The values quoted above are not corrected for the Galactic
extinction.

N.P.M. Kuin (MSSL/UCL) and J. K. Cannizzo (NASA/UMBC) report on
behalf of the Swift-UVOT team:

The Swift/UVOT observed the field of GRB 080229 (trigger #304379),
Canizzo et al. GCN CIRC. 7335
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 ) starting 2008:02:29 at 17:06:22 UT
with a 9.4 s setling image followed at 17:06:41 UT with a finding
chart. No afterglow is detected at the position of the enhanced
XRT position in the finding chart, nor in the three subsequent
exposures.

The source is near a bright star and may be affected by it.
Therefore a small aperture was used and the background was determined
for a region at equal distance to the nearby star.

The following 3-sigma upper limits (in the UVOT photometric system,
Breeveld et al., GCN Circ. 6614
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 ) were determined at the XRT
position (RA=15:12:52.53, DEC= -14:42:19.3, J2000):

Filter  Tstart(s)  Tstop(s)  Exp(s)  Mag (3-sigma Upper Limits)

 wh      101       200        99.8   > 20.9
 v       208       608       400.0   > 19.9
 wh      856       956        99.8   > 20.9
 v       962      1362       400.0   > 19.9

The values quoted above are not corrected for the expected Galactic
extinction corresponding to a reddening of E_{B-V} = 0.15 mag in the
direction of the burst (Schlegel et al. 1998).

C. Markwardt (GSFC/UMD), S. D. Barthelmy (GSFC), J. K. Cannizzo (NASA/UMBC),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
H. Krimm (GSFC/USRA), K. McLean (GSFC/UMD), D. Palmer (LANL),
A. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (GSFC/ISAS),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+303 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 080229 (trigger #304379)
(Cannizzo, et al., GCN Circ. 7335
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 ).  The BAT ground-calculated position is
RA, Dec = 228.220, -14.697 deg, which is 
   RA(J2000)  =  15h 12m 52.7s 
   Dec(J2000) = -14d 41' 50" 
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 18%.
 
The mask-weighted light curve shows an initial small peak starting
at ~T-3 sec, peaking at T_zero, and ending at ~T+12 sec.  Then there are
two smaller peaks centered on T+18 and T+28 sec.  Then comes two overlapping
large peaks on T+35 and T+39 sec with the latter tailing out to ~T+85 sec.
T90 (15-350 keV) is 64 +- 16 sec (estimated error including systematics).
 
The time-averaged spectrum from T-15.1 to T+64.9 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.91 +- 0.06.  The fluence in the 15-150 keV band is 9.0 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+40.36 sec in the 15-150 keV band
is 5.7 +- 0.2 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/304379/BA/

R.J. Smith, D.F. Bersier, S. Kobayashi, A. Monfardini, C.G. Mundell,
I. A. Steele (Liverpool JMU), A. Gomboc (U. Ljubljana),
C. Guidorzi (U. Bicocca & INAF-OAB)
P. O'Brien, E. Rol, N. Bannister (Leicester) report:

The 2-m Faulkes Telescope South (Siding Spring) robotically followed  
up GRB080229 (SWIFT trigger 304379) starting 4.6 min after the GRB  
trigger time. The automatic "detection mode" procedure did not find  
any afterglow. In manual inspection of later observations we do not  
find any optical candidate  corresponding to the XRT X-ray afterglow  
(Cannizzo et al., GCN 7335
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 ) to the following limiting magnitudes.  
Magnitude zero points are relative to the USNO measure of R=13.3 for  
the adjacent bright star.

-----------------------------------------------
Mid Time      Filter  Tot.Exposure   Lim. Mag.
since GRB

10.95 min       R        60s          18.7
28.10 min       R        180s         21.9
-----------------------------------------------

[GCN OPS NOTE(29feb08): Per editor's choice, the Subject-line
was changed from "071021" to "080229".]

B. E. Schaefer (Louisiana State) and E.S. Rykoff (UCSB), report on behalf
of the ROTSE collaboration:

ROTSE-IIIa, located at Siding Spring Observatory, Australia, responded to
GRB 080229A (Swift trigger 304379; Cannizzo et al. 2008, GCN 7335
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 ),
producing images beginning 9.8 s after the GCN notice time. An automated
response took the first image at 17:05:31.8 UT, 32.3 s after the burst,
and during the gamma-ray emission, under excellent conditions. We took 10
5-sec, 10 20-sec and 20 60-sec exposures, with continuing exposures now
ongoing. These unfiltered images are calibrated relative to USNO A2.0 (R).

Comparison to the DSS (second epoch) reveals no new sources within the
3-sigma Swift/BAT error circle; the field is not crowded.  Unfortunately,
the XRT position is close to a star of moderate brightness, so the optical
transient could possibly be hidden by the light from this star.  We do not
see any indication that the image of the star is not that of the PSF, and
preliminary image subtractions do not reveal any extra sources.  
Individual images have limiting magnitudes ranging from 14.7-16.1; we set
the following specific limits.

start UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd?
--------------------------------------------------------------------
17:05:31.8   17:05:36.8         5     14.7           32.3       N

J. K. Cannizzo (NASA/UMBC), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), J. R. Cummings (NASA/UMBC),
P. A. Evans (U Leicester), O. Godet (U Leicester), C. Gronwall (PSU),
S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU),
S. Immler (CRESST/GSFC/UMD), J. A. Kennea (PSU),
V. Mangano (INAF-IASFPA), C. B. Markwardt (CRESST/GSFC/UMD),
K. M. McLean (GSFC/UMD), A. Moretti (INAF-OAB),
P. T. O'Brien (U Leicester), J. P. Osborne (U Leicester),
C. Pagani (PSU), K. L. Page (U Leicester), D. M. Palmer (LANL),
A. M. Parsons (GSFC), T. Sakamoto (NASA/UMBC), G. Sato (GSFC/ISAS),
B. Sbarufatti (INAF-IASFPA), M. Stamatikos (NASA/ORAU),
R. L. C. Starling (U Leicester), G. Stratta (ASDC) and
E. Troja (U Leicester/INAF-IASFPa) report on behalf of the Swift
Team:

At 17:04:59 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 080229 (trigger=304379).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 228.217, -14.712 which is 
   RA(J2000)  =  15h 12m 52s
   Dec(J2000) = -14d 42' 43"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed three or four bright 
peaks with the brightest at ~T+40 sec with a duration of about 60 sec. 
The peak count rate was ~7000 counts/sec (15-350 keV), at ~40 sec
after the trigger. 

The XRT began observing the field at 17:06:29.9 UT, 90.3 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source with an enhanced position: RA, Dec 228.21888,
-14.70536 which is equivalent to:
   RA(J2000)  = 15h 12m 52.53s
   Dec(J2000) = -14d 42' 19.3"
with an uncertainty of 2.7 arcseconds (radius, 90% containment). This
location is 24 arcseconds from the BAT onboard position, within the BAT
error circle. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
8.97e+20 cm^-2 (Kalberla et al. 2005), so we cannot constrain the
redshift at this time using the relation from Grupe et al. (2007). A
summary of the promptly downlinked data is given at
http://www.swift.ac.uk/sper/304379/. 

The initial flux in the 2.5 s image was 5.98e-09 erg cm^-2 s^-2 (0.2-10
keV). 

UVOT took a finding chart exposure of 100 seconds with the White
(160-650 nm) filter starting 100 seconds after the BAT trigger. A 400
second image in V band was also taken 207 seconds after the trigger. 
No afterglow candidate has been found in the either image. The
2.7'x2.7' sub-image covers 100% of the XRT error circle. The typical
3-sigma upper limit has been about 18.5 mag in white and 18.0 in V. 
The 8'x8' region for the list of sources generated on-board covers
100% of the XRT error circle. The list of sources is typically
complete to about 18 mag. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.15. There is a F0
star with R1~13.3 in the USNO catalog nearby the XRT position which
appears in DSS images. 

Burst Advocate for this burst is J. K. Cannizzo (cannizzo AT milkyway.gsfc.nasa.gov). 
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.)