| Summary table |
|---|
| Variable |
Value |
Source |
| GRB_name_Fermi |
GRB181027076 |
|
| T0 |
1:48:46.893 UTC |
Fermi_GBM |
| ra |
225.3610° |
Swift |
| decl |
30.9370° |
Swift |
| pos_error |
8.54e-03° |
Swift |
| T90 |
89.856 s |
Fermi_GBM |
| T90_error |
5.278 s |
Fermi_GBM |
| T90_start |
1:48:46.893 UTC |
Fermi_GBM |
| fluence |
4.62e-06 erg/cm² |
Fermi_GBM |
| fluence_error |
5.50e-08 erg/cm² |
Fermi_GBM |
| T100 |
93.267 s |
|
| GBM_located |
False |
|
| mjd |
58418.075542743056 |
Fermi_GBM |
| Fermi GBM table |
|---|
| GRB_name_Fermi |
GRB181027076 |
| trigger_name |
bn181027076 |
| ra |
225.3829° |
| decl |
30.8911° |
| pos_error |
4.63e+00° |
| datum |
2018-10-27 |
| t_trigger |
1:49:47.309 UTC |
| T90 |
89.856 s |
| T90_error |
5.278 s |
| T90_start |
1:48:46.893 UTC |
| fluence |
4.62e-06 erg/cm² |
| fluence_error |
5.50e-08 erg/cm² |
| flux_1024 |
2.48e+00 erg/cm²/s |
| flux_1024_error |
2.16e-01 erg/cm²/s |
| flux_1024_time |
-6.40e-01 erg/cm²/s |
| flux_64 |
3.99e+00 erg/cm²/s |
| flux_64_error |
9.77e-01 erg/cm²/s |
| IPN table |
|---|
| GRB_name |
GRB181027A |
| ra |
225.3833° |
| decl |
30.8833° |
| pos_error |
5.00e-02° |
| Swift table |
|---|
| GRB_name |
GRB181027A |
| t_trigger |
1:48:59 UTC |
| ra |
225.3610° |
| decl |
30.9370° |
| pos_error |
8.54e-03° |
| T90 |
81.16 s |
| fluence |
2.80e-06 erg/cm² |
| GCN 23383 table |
|---|
| GRB_name |
GRB181027A |
| GCN_number |
23383 |
| Detection_method |
Swift Det |
| t_trigger |
1:48:59 UTC |
| ra |
225.3830° |
| decl |
30.8910° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 23383
SUBJECT: GRB 181027A: Swift detection of a burst
DATE: 18/10/27 01:57:37 GMT
FROM: David Palmer at LANL
A. Y. Lien (GSFC/UMBC), K. L. Page (U Leicester), D. M. Palmer (LANL)
and A. Tohuvavohu (PSU) report on behalf of the Neil Gehrels Swift
Observatory Team:
At 01:48:59 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 181027A (trigger=868984). Swift could not slew to the
burst due to an observing constraint.
The BAT on-board calculated location is
RA, Dec 225.383, +30.891 which is
RA(J2000) = 15h 01m 32s
Dec(J2000) = +30d 53' 28"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a multi-peaked
structure with a duration of about 80 sec. The peak count rate
was ~1200 counts/sec (15-350 keV), at ~49 sec after the trigger.
Due to a Sun observing constraint, Swift cannot slew to the BAT
position until 03:50 UT on 2018 November 06. There will thus be no XRT
or UVOT data for this trigger before this time.
Burst Advocate for this burst is A. Y. Lien (amy.y.lien AT nasa.gov).
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.)
|
| GCN 23384 table |
|---|
| GRB_name |
GRB181027A |
| GCN_number |
23384 |
| Detection_method |
Swift-BAT Det |
| ra |
225.3610° |
| decl |
30.9370° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 23384
SUBJECT: GRB 181027A: Swift-BAT refined analysis
DATE: 18/10/27 13:06:40 GMT
FROM: Takanori Sakamoto at AGU
S. D. Barthelmy (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF/USRA),
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-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 181027A (trigger #868984)
(Lien, et al., GCN Circ. 23383). The BAT ground-calculated position is
RA, Dec = 225.361, 30.937 deg which is
RA(J2000) = 15h 01m 26.7s
Dec(J2000) = +30d 56' 12.6"
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 96%.
The mask-weighted light curve shows a weak emission followed by a bright peak.
The emission starts at T-18.4 sec, peaks at T+47.5 sec and ends at T+85.4 sec.
T90 (15-350 keV) is 81.16 +- 10.55 sec (estimated error including systematics).
The time-averaged spectrum from T-18.45 to T+85.44 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.42 +- 0.09. The fluence in the 15-150 keV band is 2.8 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+47.81 sec in the 15-150 keV band
is 1.2 +- 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/868984/BA/
|
| GCN 23385 table |
|---|
| GRB_name |
GRB181027A |
| GCN_number |
23385 |
| Detection_method |
Fermi GBM Det |
| t_trigger |
1:49:47.310 UTC |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 23385
SUBJECT: GRB 181027A: Fermi GBM detection
DATE: 18/10/27 19:12:34 GMT
FROM: Peter Veres at UAH
P. Veres (UAH) and E. Bissaldi (Politecnico & INFN Bari)
report on behalf of the Fermi GBM Team:
"At 01:49:47.31 UT on 27 October 2018, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 181027A (trigger 56229779 / 181027076),
which was also detected by the Swift/BAT (Lien et al. 2018, GCN 23383).
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight at the GBM trigger time is 61
degrees.
The GBM light curve consists of two pulses
with a duration (T90) of about 90 s (50-300 keV).
The time-averaged spectrum from T0-84.5 s to T0+44.5 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.10 +/- 0.09 and
the cutoff energy, parameterized as Epeak, is 183 +/- 27 keV.
The event fluence (10-1000 keV) in this time interval is
(7.76 +/- 0.57)E-6 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-0.64 s in the 10-1000 keV band
is 2.48 +/- 0.22 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
|