//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22612 SUBJECT: GRB 180407A: Swift detection of a burst DATE: 18/04/07 02:04:34 GMT FROM: David Palmer at LANL A. Deich (PSU), C. Gronwall (PSU), S. J. LaPorte (PSU), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL) and A. Tohuvavohu (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 01:54:49 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 180407A (trigger=823001). Swift could not slew to the location due to an observing constraint. The BAT on-board calculated location is RA, Dec 35.241, +33.499 which is RA(J2000) = 02h 20m 58s Dec(J2000) = +33d 29' 56" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure structure with a duration of about 70 sec. The peak count rate was ~1600 counts/sec (15-350 keV), at ~0 sec after the trigger. Due to a Sun observing constraint, Swift cannot slew to the BAT position until 12:55 UT on 2018 June 19. There will thus be no XRT or UVOT data for this trigger before this time. Burst Advocate for this burst is A. Deich (aud375 AT psu.edu). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22614 SUBJECT: GRB 180407A: COATLI Upper Limits DATE: 18/04/07 04:37:08 GMT FROM: Alan M. Watson at Instituto de Astronomia UNAM Alan M. Watson (UNAM), Nat Butler (ASU), Rosa L. Becerra (UNAM), William H. Lee (UNAM), Carlos Román-Zúñiga (UNAM), Alexander Kutyrev (GSFC), and Eleonora Troja (GSFC), report: We observed the field of GRB 180407A (Deich et al., GCN 22612) with the COATLI 50-cm telescope and interim imager (http://coatli.astroscu.unam.mx) at the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir from 2018-04-07 02:26:12 to 03:01:38 (0.52 to 1.12 hours after trigger) obtaining a total of 510 seconds of exposure in the w filter. The images were obtained at high airmass (above 3.1) and during twilight. For a source within the Swift/BAT error circle, in comparison with the USNO-B1 catalog, we obtain the following 10-sigma upper limit: w > 16.53 This magnitude is in the USNO system and is not corrected for Galactic extinction in the direction of the GRB. We thank the COATLI technical team (Fernando Ángeles, Oscar Chapa, Salvador Cuevas, Alejandro Farah, Jorge Fuentes, Rosalía Langarica, Fernando Quirós, and Carlos Tejada) and the staff of the Observatorio Astronómico Nacional. -- Dr. Alan M. Watson Instituto de Astronomía Universidad Nacional Autónoma de México //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22616 SUBJECT: GRB 180407A: Swift-BAT refined analysis DATE: 18/04/07 19:09:11 GMT FROM: Amy Lien at GSFC H. A. Krimm (NSF/USRA), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), A. Deich (PSU), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-240 to T+144 sec from the recent telemetry downlink, we report further analysis of BAT GRB 180407A (trigger #823001) (Deich et al., GCN Circ. 22612). Note that due to the Sun constraint, Swift could not slew to the burst location, and no data were collected for the burst after ~ T+144 s. The BAT ground-calculated position is RA, Dec = 35.236, 33.513 deg which is RA(J2000) = 02h 20m 56.6s Dec(J2000) = +33d 30' 48.4" with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 52%. The mask-weighted light curve shows a weak pulse that starts at ~ T-20 s and ends at ~ T+110 s. The pulse consists of several overlapping peaks. The largest peak occurs at ~ T+2 s. T90 (15-350 keV) is 95.9 +- 29.8 sec (estimated error including systematics). Note that because the burst went out of the BAT field of view at T+144 s, T90 reported here might not capture the entire burst duration. The time-averaged spectrum from T-20.58 to T+107.48 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.94 +- 0.20. The fluence in the 15-150 keV band is 1.4 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+2.18 sec in the 15-150 keV band is 0.9 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/823001/BA/