GRB 180407A

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.)

Alan M. Watson (UNAM), Nat Butler (ASU), Rosa L. Becerra (UNAM), William
H. Lee (UNAM), Carlos Rom��n-Z����iga (UNAM), Alexander Kutyrev (GSFC), and
Eleonora Troja (GSFC), report:

We observed the field of GRB 180407A (Deich et al., GCN 22612
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 ) with the
COATLI 50-cm telescope and interim imager
(http://coatli.astroscu.unam.mx) at the Observatorio Astron��mico
Nacional on the Sierra de San Pedro M��rtir 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 ��ngeles, Oscar Chapa,
Salvador Cuevas, Alejandro Farah, Jorge Fuentes, Rosal��a Langarica,
Fernando Quir��s, and Carlos Tejada) and the staff of the Observatorio
Astron��mico Nacional.


-- 
Dr. Alan M. Watson
Instituto de Astronom��a
Universidad Nacional Aut��noma de M��xico

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
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 ). 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/