GRB 030501

S. Mereghetti, D. Gotz, J. Borkowski on behalf of the IBAS Localization
Team, S. Shaw and T. Courvoisier on behalf the INTEGRAL Science Data
Centre and the INTEGRAL Science Working Team

report the detection of a GRB at 03:10:18 UTC at coordinates
RA 19h 05m 30s DEC +06deg 18' 26'' (J2000)
with an uncertainty of 3 arcmin radius.

The burst lasted about 40 seconds.

K. Hurley, on behalf of the Ulysses GRB team, and

A. von Kienlin, G. Lichti, and A. Rau, on behalf of the
INTEGRAL SPI-ACS GRB team, report:

Ulysses and INTEGRAL (SPI-ACS) also observed this burst (GCN 2183
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 ).  As
observed by Ulysses, it had a duration of approximately 75 seconds, a
25-100 keV fluence of approximately  1.1E-06 erg/cm2, and a peak flux
of approximately  4.9E-07 erg/cm2 s over 0.25 seconds.  Because this
event was quite weak, these parameters are uncertain by a factor of
about 2.

We have triangulated it to a preliminary annulus centered  at RA,
Decl(2000)= 332.536, -37.604 degrees, whose radius is 61.259 +/-  0.294
degrees (3 sigma ).  This annulus is consistent with, but does not
constrain, the IBIS localization given in GCN 2183
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 .

This annulus may be improved.

Michel Boer and Alain Klotz (CESR/CNRS/UPS), on behalf of the TAROT team report:

We observed the localisation of GRB 030501 given by INTEGRAL (GCN Circ. 2183
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 ).
The observations started at 3h10m37.6s, less than 20 seconds after the burst 
trigger, while it was still active. 

We do detect an object in the INTEGRAL error box which is not present on the 
DSS. The position of the new source is
RA = 19h05m37.9s
DEC = +6d18'51"
with a preliminary uncertainty of 3 arcsec.
On our 14, 30s duration, images the flux seems constant in first approximation, 
at an R magnitude of 14.9 +- 0.2. Hence the new source may be a variable star, 
detected seremdipitously in high state.

Work is still in progress on our images to investigate the nature of this 
object. A preliminary report and finding chart are available at the following 
URL: http://www.cesr.fr/~klotz/grb030501/

This message is quotable

D. Fox (Caltech) reports:

"The candidate GRB030501 optical afterglow of Boer & Klotz (GCN 2188
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 )
is present in archival images of the Second Palomar Optical Sky Survey
(XDSS) and the Two-Micron All-Sky Survey (2MASS).  Although the
object, which appears to be a star, is undetected in the XDSS B-band
image, and faint in the XDSS R-band image, it is well-detected in the
XDSS I-band image and extremely bright (among the brightest stars in
the near field) in 2MASS J, H, and Ks images.  These archival images
may be viewed at the web page:

   http://www.astro.caltech.edu/~derekfox/grb030501/tarot.html

We conclude that the object is not the optical afterglow of GRB030501.
We also note in passing that the optical extinction in this field,
very near the Galactic disk, is extremely high, E(B-V) = 14.8 mag from
the dust maps of Schlegel, Finkbeiner, & Davis (1998).  Such
highly-reddened objects are thus to be expected."

S. Golenetskii, E. Mazets, V. Pal'shin, and D. Frederiks on behalf
of Konus-Wind and Helicon/Coronas-F teams report

Data reported in GCN 2194
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  were affected by error in time delay.

Correct Konus-Wind - Helicon annulus is:
RA(2000) = 224.210 deg,
Decl(2000) = -21.142 deg,
Radius = 73.23 +/- 0.70 degrees (3 sigma ).

This annulus intersects the IPN annulus (GCN 2186
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 ) to form two
error boxes, only one of which has the correct ecliptic latitude.
Preliminary 3 sigma error box has approximate area of 400 sq. arcmin :
                         RA(2000)    Dec(2000)
ERROR BOX CENTER:      283.581        23.875
ERROR BOX CORNER 1:    284.167        24.337
ERROR BOX CORNER 2:    284.212        24.275
ERROR BOX CORNER 3:    283.001        23.410
ERROR BOX CORNER 4:    282.956        23.472





-- 
Dmitry Frederiks
[aka Fred]
-------------------------------------------------------
Lab for High Energy Astrophysics, Space Research Dept,
A.F.Ioffe Phys.-Tech. Institute, St.Petersburg, Russia
-------------------------------------------------------

E. O. Ofek, Y.-J. Choi, A. Gal-Yam, Y. Lipkin
(Wise observatory, TAU) report:

We have observed the full error box of GRB030501 (Mereghetti et al. 2003, 
GCN 2183
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 ) using the Wise observatory 1m telescope + SITe CCD camera,
starting 2003, May 2nd, 00:05 UT (16.5 hours after the burst).
Two 600s R-band frames were obtained.

Comparison of the images with the POSS-II E plate
reveals no new optical sources, to a limiting magnitude
of R=20.0, within the INTEGRAL error circle.

V.Rumyantsev, E.Pavlenko (CrAO), A.Pozanenko (IKI) report:

We have imaged the error box of GRB030501 (Mereghetti et al. 2003, GCN 2183
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 )
with AT-64 telescope of CrAO. Several unfiltered images were taken  on May,
1 21:59-23:12 (18.8 hours after GRB)  and   May, 3 22:36-23:34 (2.8 days
after GRB). Visual comparison with DSS-2I and comparison of the combined
images in different epochs (May 1 and May 3) reveals no new or fading
objects within GRB error box.

Log of observations is following:

Mid time    exposure   limit (3 sigma)
01.93200    17x120     20.1
03.96599    21x120     20.0

The combined image of May, 1 can be found in http://grb.rssi.ru/GRB030501/

This message may be cited.

Alain Klotz and Michel Boer (CESR/CNRS/UPS), on behalf of the TAROT team 
report :

We co-added 25 unfiltered 30s duration frames, taken between 20s and 17min 
after GRB 030501 (Mereghetti et al., GCNC 2183). We do not detect any new 
source up to the limiting magnitude of R=18.0 .

The source reported in GCN Circ. 2188
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  is a bright infrared source as indicated 
by Fox et al (GCNC 2189). It was detected by TAROT because of its residual 
sensitivity to IR for the unfiltered images.

The data will be soon available on the TAROT site, and are already accessible 
through the following URL : http://www.cesr.fr/~klotz/grb030501

This message is citable.