{
  "subject": "Swift triggered on the HMXB 1A 1118-61",
  "submitter": "K.L. Page at U Leicester <klp5@leicester.ac.uk>",
  "bibcode": "2026GCN.43435....1G",
  "body": "R. Gupta (NASA GSFC) and K. L. Page (U Leicester) report on behalf of\nthe Neil Gehrels Swift Observatory Team:\n\nAt 06:28:58 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated the HMXB 1A 1118-61 (trigger 1441823). Swift slewed soon after \nthe event. The BAT on-board calculated location is \nRA, Dec 170.183, -61.905 which is \n   RA(J2000) = 11h 20m 44s\n   Dec(J2000) = -61d 54' 17\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve showed a complex\nstructure.  This is an image-triggered event.\n\nThe XRT began observing the field at 06:35:17.6 UT, 378.7 seconds after\nthe BAT trigger. XRT found a bright X-ray source located at RA, Dec\n170.2403, -61.9170 which is equivalent to:\n   RA(J2000)  = 11h 20m 57.67s\n   Dec(J2000) = -61d 55' 01.2\"\nwith an uncertainty of 5.5 arcseconds (radius, 90% containment). This\nlocation is 106 arcseconds from the BAT onboard position, within the\nBAT error circle. This position is 4.3 arcseconds from a known X-ray\nsource: LSXPS J112057.1-615459. This source is in the Swift XRT LSXPS \ncatalogue with a mean 0.3-10 keV count-rate of 0.2537 +/- 0.0012\nct/sec; see https://www.swift.ac.uk/LSXPS/LSXPS%20J112057.1-615459 for\ndetails of these previous observations. No event data are yet available\nto determine the column density using X-ray spectroscopy.\n\nThis trigger occurred just as Swift was exiting the SAA, so it is not\nclear at this time whether the source has actually brightened, or if\nthe trigger was caused by the enhanced particle background.\n\n",
  "createdOn": 1768633158842,
  "submittedHow": "email",
  "circularId": 43435
}