{
  "bibcode": "2022GCN.32353....1I",
  "body": "W. Iwakiri (Chuo U.), M. Shidatsu (Ehime.U), M. Serino (AGU), K. C. Gendreau, Z. Arzoumanian (NASA/GSFC), \nT. Enoto, T. Mihara (RIKEN)\n\nWe report on initial NICER observations of GRB 220706A (GCN #32329) carried out on 2022 July 7. \nThe observations were carried out in two parts. The first epoch began at 01:36 UT, approximately a half-day \nafter the Swift/BAT trigger (GCN #32329), and ended at 03:34 UT, with ~1.5 ksec of exposure across two \nsuccessive orbits of the International Space Station (ISS). The lightcurve shows a slow decay: \nthe NICER-measured X-ray flux decreased from 8 x 10-13 to 6 x 10-13 erg/cm2/s in the 0.3-10 keV band. \nThe emission overall was soft, with hardness ratio of 0.1 between the 0.3-2.0 and 2.0-10.0 keV bands. \nThe second epoch was from 17:08 to 22:09 UT (~1 day after the Swift/BAT detection), with 3.4 ksec exposure \nin total. We found re-brightening of the afterglow: the NICER average flux during the second epoch \nwas 6.5 x 10-12 erg/cm2/s in 0.3-10 keV, with a hardness ratio of 0.6. The result suggests that the spectrum \nhas significantly hardened compared with the first-epoch results, unlike typical GRBs. \n\nNICER will continue to monitor this source. Multi-wavelength followup observations are strongly encouraged.\n\nNote: Because the nature of the source is unknown, this message is cross-posted to ATel and GCN.",
  "circularId": 32353,
  "createdOn": 1657325278000,
  "email": "serino@phys.aoyama.ac.jp",
  "subject": "GRB 220706A : NICER detection of re-brightening 1 day after the Swift trigger",
  "submitter": "Motoko Serino at Aoyama Gakuin U.  <serino@phys.aoyama.ac.jp>",
  "eventId": "GRB 220706A"
}