GRB 991014

Giangiacomo Gandolfi, on behalf of BeppoSAX Mission Scientist, reports:

On Oct.14, 21:52:34 UT  a GRB (GRB991014) was detected
simultaneously by the GRBM and WFC of BeppoSAX (also BATSE trigger 7803).

Preliminary coordinates from WFC are:
R.A.(2000)=102.777
DEC(2000)= 11.594

with an error radius of about 6'.

K. Hurley, on behalf of the Ulysses GRB team, and M. Feroci, on behalf
of the BeppoSAX GRB team, report:

We have obtained a preliminary IPN annulus for GRB991014 (GCN 417
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 ).  This
annulus is centered at RA=162.2315 deg., Decl.=-19.0726 deg. (J2000),
and has a radius of 66.1316 +/-  0.0275 deg. (3 sigma).  It intersects the
BeppoSAX NFI error circle (GCN 373
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 ) to form an ~36 arcmin.^2 error
box whose corners are:

RA(2000)	Decl.(2000)
6 h 50 m 47 s  +11 o  31' 53"
6 h 51 m 08 s  +11 o  41' 38"
6 h 50 m 59 s  +11 o  29' 58"
6 h 51 m 21 s  +11 o  40' 32"

A map may be found at ssl.berkeley.edu/ipn3/991014/.  Some
refinements to this annulus are expected.

The previous GCN circular incorrectly referenced an NFI error circle;
it should have read:

K. Hurley, on behalf of the Ulysses GRB team, and M. Feroci, on behalf
of the BeppoSAX GRB team, report:

We have obtained a preliminary IPN annulus for GRB991014 (GCN 417
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 ).
This annulus is centered at RA=162.2315 deg., Decl.=-19.0726 deg.
(J2000), and has a radius of 66.1316 +/-  0.0275 deg. (3 sigma).  It
intersects the BeppoSAX WFC error circle to form an ~36 arcmin.^2 error
box whose corners are:

RA(2000)	Decl.(2000)
6 h 50 m 47 s  +11 o  31' 53"
6 h 51 m 08 s  +11 o  41' 38"
6 h 50 m 59 s  +11 o  29' 58"
6 h 51 m 21 s  +11 o  40' 32"

A map may be found at ssl.berkeley.edu/ipn3/991014/.  Some
refinements to this annulus are expected.

K. Hurley, on behalf of the Ulysses GRB team, and M. Feroci, on behalf
of the BeppoSAX GRB team, report:

The recently reported NFI error circle for GRB991014 (BeppoSAX MAIL
99/28) is within the IPN annulus for this burst (GCN 419
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 ).  The error
circle is slightly reduced in size by the annulus.  The corners of the
IPN/NFI error box are:

   RA(2000)          DEC(2000)
6 h 50 m 55 s    +11 o 35 ' 34 "
6 h 50 m 57 s    +11 o 36 ' 43 "
6 h 51 m 06 s    +11 o 33 ' 23 "
6 h 51 m 11 s    +11 o 35 ' 54 "

This makes it quite likely that the NFI source is indeed the X-ray
counterpart to GRB991014.  The map at ssl.berkeley.edu/ipn3/991014/ has
been updated to show the NFI source position.

H. S. Park, R. Porrata (LLNL), G. Williams (Clemson Univ.)
report on behalf of the LOTIS collaboration:
  
The Super-LOTIS telescope (0.6 m reflector; 0.8 deg fov) responded to the   
BeppoSAX alert (GCN 417
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 ) automatically on Oct 15.528 UT (14.8 hours after
the GRB: 5:40 AM local time). The original BATSE trigger 7803 came 
at 2:21 PM local time and another BATSE trigger 7805 occuring the same 
evening prevented us from covering the GRB991014 location at earlier times.  
At the time of this trigger, our camera was not running the TEs because of 
recent replacement of the CCD (Super-LOTIS is in the integration phase 
at LLNL.) No astronomical filter was used for these imaging.
  
We obtained 9 images (40 s integration time each) before dawn. We have 
visually compared these individual images and the summed image with the 
Digital Sky Survey. No new source was identified within the BeppoSAX/WFC 
error box brighter than R = 16.8 +/- 0.3 from the summed image.
 
The LOTIS (17.6 x 17.6 deg fov) telescope was also running and covered 
trigger 7805; so its sky patrol did not obtain early coverage of the 
GRB991014 location. The Super-LOTIS limit supercedes the LOTIS limit 
for the BeppoSAX triggered images.
 
Further analysis is in progress and associated data will be placed
on our web page.

The U.S. Naval Observatory GRB team (A.A. Henden, F.J. Vrba, B.
Canzian, C.B. Luginbuhl, S.E. Levine, H.H. Guetter, J.A. Munn), D.H.
Hartmann (Clemson Univ.), M.C. Jennings (IGPP, UCR visitor)

report a BVRcIc photometry file for the northern half of
the WFI error box of GRB 991014.  This file can be found at:
  ftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/grb991014.dat
One marginal photometric night with a wide variety of
Landolt standards having large color and airmass differences was used.
Typical zero point errors are 0.02mag, to be added to the Poisson
errors reported in the file.  All stars brighter than V=14 are
saturated and should be ignored.  We intend to observe additional
nights in November to further calibrate this field, and will
update the file accordingly.
  The team also acquired I-band photometry with the 1.55-m
telescope of the NFI error box, and R-band photometry with
the 1.0-m telescope of the entire WFI error box, from about
991015 1030 UT until 1230 UT.  Due to the Huntsville GRB
meeting, this data is being slowly analyzed by a shrunken
staff.  It is clear again tonight (991016 UT) and additional
R-band photometry with the 1.0-m of the NFI error box is scheduled.

This GCN note can be cited.

J. Thorstensen (Dartmouth), R. Uglesich, J. Halpern, N. Mirabal
(Columbia U.), E. Costa, M. Feroci, L. Piro (IAS/CNR, Rome)
report on behalf of the MDM Observatory GRB follow-up team
and the BeppoSAX team:

"We imaged the field of GRB 991014 in the R band starting on
Oct. 15.38 UT, 11.2 hours after the burst, using the MDM 
Observatory's 1.3m and 2.4m telescopes.  The entire 6' radius 
error circle from the BeppoSAX WFC (Gandolfi, GCN #417
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 ) was covered
at the 1.3m, and the entire 2' radius NFI error circle of a possible
X-ray afterglow (BeppoSAX MAIL n. 99/28) was covered at the 2.4m.
There was no new object brighter than the digitized POSS-II limit in 
the WFC error circle.

We reobserved the NFI error circle on the 2.4m on Oct. 16.42 UT.
Seeing was 1.1-1.2 arcseconds on both nights, and the 5 sigma
limiting magnitude was R = 23.1.  No variable object was detected
in the NFI error circle.  This magnitude limit is referenced to a
USNO star at position (J2000) RA 06:51:03.17, Dec +11:36:42.6 which
has R = 17.61 +/- 0.02 according to the recent calibration of
Henden et al. (GCN #422
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 ).

This message may be cited."

T. Giblin, R. M. Kippen (UAH/MSFC), and M. Sahi (USRA/MSFC) report on
behalf of the BATSE Team:

On 1999 October 14.911512 UT, BATSE triggered on GRB991014 (trigger # 7803).
The burst time history shows a primary emission pulse comprised of several
sub-pulses lasting a few seconds followed by a weak and soft pulse. The T90 
and T50 measured durations are 4.67 (+/- 0.47) and 1.22 (+/- 0.14) seconds, 
respectively. Although short, this burst is still classified as a Class I 
burst in the BATSE GRB Hardness-Duration scatter plot. The burst is soft, 
with marginal emission above 300 keV and an energy fluence hardness ratio 
(100-300 keV / 50-100 keV) equal to 1.36 (+/- 0.13). The 50-300 keV peak 
flux of the burst measured on the 64 ms timescale is 2.58 (+/- 0.26) 
photons/s/cm^2 and 4.87 (+/- 0.53) ergs/s/cm^2, placing it in the upper
32% of the BATSE peak flux distribution. The fluence (> 25 keV) of the 
burst is 1.712 (+/- 0.471) x 10^-6 ergs/cm^2, ranking in the top 58% of
the fluence distribution. The BATSE location is consistent with the 
BeppoSAX WFC error circle and IPN annulus. The BATSE light curve will 
soon be available at:

	http://www.batse.msfc.nasa.gov/~kippen/batserbr/

G. B. Taylor (NRAO), D. A. Frail (NRAO), and S. R. Kulkarni (Caltech) 
report on behalf of a larger collaboration:

"We have imaged the field of GRB 991014, centered on the BeppoSAX NFI
source (BeppoSAX mail n 99/28) with the Very Large Array (VLA) at 1.4
GHz and 8.46 GHz beginning on Oct 16.59 UT. No sources are visible
within the region bounded by the NFI error circle above a 5-sigma
level of 125 microJy (8.46 GHz) and 220 microJy (1.4 GHz). Further
observations are planned."

This message is citeable.

S. Guziy, A. Shlyapnikov (Astro. Obs. Nikolaev Univ.),
R. Hudec (Astro. Inst. Ondrejov),
report:

"We obtained 2 images in the R band of the region for GRB991014
(GCN 417
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 ). The total integration time is 1200 s (2x600s).
These images were started  Oct. 15.96, after the 25.2 hours
after the burst on the 0.7 m telescope Astro. Obser. of
Nikolaev Univer. The limiting magnitude was about 19.2.
Comparison with the Digitized Sky Survey does not reveal
any new object brighter than about 19.5 in the intersection
of the error regions.


This message may be cited."

J. in 't Zand and L. Kuiper, Space Research Organization Netherlands, 
Utrecht; L.A. Antonelli, Osservatorio Astronomico di Roma; A. Coletta, 
S. Rebecchi, M. Stornelli, M. Capalbi, BeppoSAX Science Operations Center, 
Telespazio, Rome; and G. Gandolfi, Istituto di Astrofisica Spaziale, CNR, 
Rome, report: "GRB 991014 was observed with the Narrow Field Instruments 
(NFI) on board BeppoSAX from Oct. 15.4 to 16.4 UT (starting 13.0 hrs 
after the burst trigger time). In the 2-10 keV image of all data from both
Medium-Energy Concentrator Spectrometer units 2 and 3, two point sources are 
apparent within the WFC/IPN combined error box (Tassone et al., IAUC 7281, 
Hurley et al. GCN 419
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 ). Their positions are R.A. = 6h51m03s, 
Decl. = +11d36'05" (S1) and R.A. = 6h50m59s, Decl. = +11d33'09" (S2, 
Eq. 2000.0). The error radius for both sources is 1'.5. Neither S1 nor S2 show 
conclusive evidence of decay, but this is a statistical issue rather than a 
meaningful statement about the decay index. To search for a decay and 
possibly identify the afterglow with S1 or S2, another NFI pointing is 
scheduled for Oct. 24.

R. Uglesich, J. Halpern (Columbia U.), & J. Thorstensen (Dartmouth)
report:

"In addition to the MDM observations reported in GCN #423
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 , we
reobserved the entire 6' radius error circle of the BeppoSAX WFC
(Gandolfi, GCN #417
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 ) with the 1.3m because it is not known if either
of the reported NFI X-ray sources (in 't Zand et al. GCN #427
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 ) is
associated with the GRB.  The 1.3m observations were centered on 
Oct. 15.45 UT and Oct. 16.48 UT, and reach a  5-sigma limiting
magnitude of R = 22.6 on the first night, and R = 22.8 on the second 
night.  We used a non-standard, broad R filter which nevertheless
calibrates very well with Landolt (1992) standards that we obtained.
We find R = 17.64 for the star mentioned in GCN #423
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 , which is consistent
with the USNO calibration (R = 17.61 +/- 0.02).  Although we have not yet 
carried out a detailed photometric analysis of the entire WFC circle,
careful visual inspection reveals no variable object to a limit of 
approximately R > 22.6 at 13 hours after the burst.  The images from
the MDM 2.4 reported in GCN #423
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  cover the error circles of both of 
the NFI sources, and our previously reported limit of R > 23.1 at
11.2 hours still applies.

We also note that Galactic extinction in this direction is estimated 
to be E(B-V) = 0.202 from IRAS dust maps (Schlegel et al. 1998),
so A_R is a modest 0.54 magnitudes.

A CCD image of the field of the NFI sources is posted at
http://www.astro.bio2.edu/grb/

This message may be cited."

J. in 't Zand, Space Research Organization Netherlands (SRON), 
Utrecht; L.A. Antonelli, Osservatorio Astronomico di Roma; L. Kuiper, SRON;
S. Rebecchi, M. Stornelli, D. Ricci, BeppoSAX Science Operations Center, 
Telespazio, Rome; and G. Gandolfi, Istituto di Astrofisica Spaziale, CNR, 
Rome, update the information given in GCN Circ. 427
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 .: "GRB 991014 was 
observed with the Narrow Field Instruments on board BeppoSAX on two 
occasions: Oct. 15.4-16.4 UT (0.5-1.5 d after the burst) and Oct. 
24.8-25.9 (9.9-11.0 d after the burst). In the 2-10 keV images from both 
Medium-Energy Concentrator Spectrometer units 2 and 3, two sources only 
3' apart are within the combined WFC/IPN error regions of the burst (IAUC 
7281, GCN 419
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 ). Their positions are R.A. = 6h51m03s, Decl. = +11d36'05" 
(SAX J0651.0+1136 = S1 in GCN 427
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 ; Eq. 2000.0; error radius 1.5') and 
R.A. = 6h50m57s, Decl. = +11d33'13" (SAX J0651.0+1133 = S2 in GCN 427
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 ; 
error radius 1'). The first source is not detected in the second 
observation. The 3 sigma upper limit translates to a decay by at least a 
factor of 2.2. The second source did not change significantly, the 
intensity change is 10+/-20%. Therefore, we identify SAX J0651.0+1136 as 
the X-ray afterglow of GRB 991014.