Gamma-ray Burst 020410

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN/BACODINE POSITION NOTICE
  

  
  TITLE:           GCN/SAX_WFC BURST POSITION NOTICE
  NOTICE_DATE:     Wed 10 Apr 02 14:48:23 UT
  NOTICE_TYPE:     SAX-WFC Final
  GRB_DATE:        12374 TJD;   100 DOY;   02/04/10
  GRB_TIME:        38480.00 SOD {10:41:20.00} UT
  GRB_SAX_RA:      331.768d {+22h 07m 04s} (J2000),
                   331.852d {+22h 07m 25s} (current),
                   329.849d {+21h 59m 24s} (1950)
  GRB_SAX_DEC:     -83.821d {-83d 49' 14"} (J2000),
                   -83.810d {-83d 48' 34"} (current),
                   -84.064d {-84d 03' 50"} (1950)
  GRB_SAX_ERROR:   0.030 [deg radius (stat+sys), 1-sigma]
  GRB_SAX_INTEN:   unknown
  SUN_POSTN:        18.84d {+01h 15m 21s}   +7.97d {+07d 58' 05"}
  SUN_DIST:         93.72 [deg]
  MOON_POSTN:      356.91d {+23h 47m 39s}   -6.81d {-06d 48' 25"}
  MOON_DIST:        77.59 [deg]
  COMMENTS:        SAX-WFC GRB Coordinates.  
  COMMENTS:        Possible GRB or X-Ray Flash. GRBM was not available during burst.  
   
  
  

• GCN notice #1349 = BeppoSAX mail n. 02/07
  On Apr. 10, 10:41:20 UT a possible GRB has been detected in BeppoSAX WFC2. Unfortunately GRBM was switched off at that time and the nature of the transient is still under examination. A GRB or X-ray flash classification is however very probable.
  Refined coordinates are:

   R.A.(2000)= 331.768
   DEC.(2000)= -83.821
  

  The error radius is 2'.
  G. Gandolfi on behalf of BeppoSAX Mission Scientist
• GCN notice #1350
  P. Kilmartin (p.kilmartin@phys.canterbury.ac.nz) and A. Gilmore, Mount John Observatory, on behalf of the AAVSO International GRB Network, report:
  We have imaged the entire BeppoSAX error circle of the possible GRB020410 (Gandolfi GCN1349), using the MJO 0.6m telescope and ST-9E CCD. Fifteen unfiltered 60-second exposures, centered on UT 020410.691 (6hrs after the burst), were taken and median combined. Comparing against the POSS-II red plate, we see nothing new down to approximately R=19.
  The AAVSO would like to thank the Curry Foundation for supporting the AAVSO International GRB Network.
• GCN notice #1355
  GRB 020410, optical observations
  A. J. Castro-Tirado, J. Gorosabel, J. M. Castro Cerón (Instituto de Astrofísica de Andalucía, IAA-CSIC,Granada) B. Nelson, P. Tristram (Univ. of Canterbury) and Ph. Yock (Univ. of Auckland),
  report:
  We have obtained several R-band exposures centred at the GRB 020410 error box (Giandolfi et al. GCN#1349) starting on 10 Apr 2002 at 16:58 UT, i.e. 6.28 hr after the trigger, with the 0.6 m MOA telescope at the Mt. John University Observatory in New Zealand. A visual inspection of the images does not reveal any transient objects down to the DSS-2 limiting magnitude within the 2' BSAX error box.
  This message is quotable.
• GCN notice #1358 = BeppoSAX Mail n. 02/10
  GRB020410: BeppoSAX NFI observation
  A BeppoSAX TOO observation of GB020410 has started about 20 hours after the GRB. A preliminary analysis of MECS (1.6-10 keV) image of the first orbits shows a bright unknown source in the WFC error circle.
  The position is:

    RA(2000) = 331.603
    Delta(2000) = -83.82
  

  The error radius is 1 arcminute.
  G. Gandolfi
  on behalf of BeppoSAX Mission Scientist
• GCN notice #1366 =
  GRB020410: second BeppoSAX NFI observation
  On Apr. 12 at 17:00 U.T. a second BeppoSAX NFI observation has been started, 54.3 hours after the burst. The unknown source previously reported is detected again and its flux is decreased about a factor 2. This fact makes more probable the connection with the WFC transient of April the 10th whose nature is however still to be understood. Further analysis are in progress.
  Giangiacomo Gandolfi on behalf of BeppoSAX Mission Scientist
• GCN notice #1374
  L. Nicastro, Istituto di Astrofisica Spaziale e Fisica Cosmica (IASF-CNR), Palermo; L. Piro, G. Gandolfi, M. Feroci, (IASF-CNR), Rome; M. Capalbi, M. Perri, ASI Science Data Center, Rome; J. Heise, J. in't Zand, Space Research Organization Netherlands, Utrecht, report:
  "BeppoSAX performed two NFI observations of the candidate GRB 020410. Start times were Apr. 11, 06:53 UT (20.2 hrs after the burst) and Apr. 12 16:49 UT (54.3 hrs after the burst). We detect a single unknown slowly fading source in both observations whose refined coordinates (J2000) are:

     RA: 22 06 25.8, Dec: -83 49 27
  

  This is 1.3 arcmin from the WFC derived position (GCN 1349) and 15 arcsec from the quick-look analysis derived one (GCN 1366). The error circle radius is 20 arcsec (90% confidence). This is the smallest ever reported for a BSAX-NFI detected GRB. For more information about NFI source coordinates accuracy see the BeppoSAX-ASDC report at the URL: http://www.asdc.asi.it/bepposax/coord_correction.html
  Images of the two observations and the decay behavior are posted at the URL: http://www.ifcai.pa.cnr.it/~nicastro/saxtoo-grb020410
  We note that no gamma-ray detection was reported so far (the BSAX-GRBM was not operative). This fact, the X-ray properties of the WFC (2-28 keV) prompt event and the spectral/temporal behavior of the afterglow strongly support the hypothesis of a XRF or anomalous GRB.
  (Sub-)arcsec position accuracies obtainable with Chandra or XMM-Newton would greatly facilitate deeper studies at other wavelengths."
  This message may be cited.

  ToO #1 - MECS 1.6-10 keV image:

  

  ToO #2 - MECS 1.6-10 keV image (scaled to ToO #1):

  

  Temporal behavior (1.6-10 keV):

  
• GCN notice #1380
  D. A. Frail (Caltech/NRAO), M. H. Wieringa (ATNF), E. Berger (Caltech), and R. Wark (ATNF) report on behalf of a larger collaboration:
  "Beginning on 2002 April 23 at 8:00 UT we observed a region centered on the position of the fading X-ray source reported by Nicastro et al. (GCN #1374) with the Australia Telescope Compact Array (ATCA) at 8.7 GHz. An image made of the entire error circle (20-arcsec radius) shows no radio sources above a 4-sigma level of 200 microJy.
  This message may be cited."
• GCN notice #1453
  A.S. Fruchter, A.J. Levan, I. Burud (STScI), P.E. Nugent (LBNL) report for the larger GOSH Collaboration:
  We observed the field of GRB 020410 (GCN 1349) with HST using the STIS CCD in open (50CCD) mode on the 8 May and 14 June 2002. The 50" field of STIS was centered on the refined NFI BeppoSax postion of Nicastro et al. (GCN 1374), which has a 90% confidence error-circle radius of 20".
  We find a variable source located at RA=22h 06m 31.87s, DEC=-83d 49m 28.3" where the astrometry has been derived from the headers of the two HST images (which agree to approximately 0."5). This position is offset from the center of the NFI error circle by approximately 6".
  Using a zeropoint of V=26.3 for the wide-band STIS 50CCD image, we find the source had a magnitude of V=25.35 on 8 May and 26.90 on 14 June, where the uncertainty in the photometry is dominated by the color correction (which one might expect to be of order 0.1 mags). The source is largely point-like, though it lies near a 25th magnitude galaxy, and shows possible evidence of a faint underlying object.
  The decline of ~1.55 magnitudes between the two observation dates is equivalent to an effective power-law decay of -1.65. While this value is completely consistent with the late-time decay of the optical afterglow of a GRB, we cannot rule out the possibility that a supernova, unrelated to the GRB, occurred in our search region. Given the rates of discovery by HST of supernovae in deep images of random fields (c.f. Gilliland, Nugent and Phillips 1999) we conservatively estimate a ~5% chance that this could be such a chance superposition. Further observations, which we expect will give us both a late-time magnitude and color, should allow us to distinguish between these possibilities.
  Were the source to have faded consistently as a power law of exponent -1.65 from early after the burst, then its magnitude would have been ~17 at 6 hours after burst when observations by Castro-Tirado et al. (GCN 1355), which reached the DSS-2 limit, failed to detect a counterpart. BeppoSAX observations (GCN 1358, 1366) taken 20 and 54 hours after burst indicated that the x-ray afterglow associated with the GRB fell by only a factor of two, consistent with an effective power law decline of -0.9. Therefore a break may be the most likely explanation for the non-detection of this transient in early optical observations.
  If, as expected, this is indeed the OT of GRB 020410, this would be the first time that HST (or any orbiting observatory) has discovered the OT of a GRB.
  The HST images of the field of GRB 020410 can be found at http://www.stsci.edu/~fruchter/GRB/020410.
• Full paper in Nicastro et al. 2004, A&A, 427, 445