GRB081215A

This page lists all entries on GRB081215A in GRBweb

Summary Fermi GBM GCN 8671 GCN 8673 GCN 8678 GCN 8679 GCN 8684 GCN 8702 GCN 8706 GCN 11574

Summary table
Variable Value Source
GRB_name_Fermi GRB081215784
T0 18:48:36.846 UTC Fermi_GBM
ra 78.2010° GCN_circulars,IPN Triangulation
decl 17.5750° GCN_circulars,IPN Triangulation
T90 5.568 s Fermi_GBM
T90_error 0.143 s Fermi_GBM
T90_start 18:48:38.062 UTC Fermi_GBM
fluence 5.47e-05 erg/cm² Fermi_GBM
fluence_error 5.87e-08 erg/cm² Fermi_GBM
T100 6.784 s
GBM_located False
mjd 54815.783759791666 Fermi_GBM
Fermi GBM table
GRB_name_Fermi GRB081215784
trigger_name bn081215784
ra 125.6000°
decl 54.0000°
pos_error 2.47e+00°
datum 2008-12-15
t_trigger 18:48:36.846 UTC
T90 5.568 s
T90_error 0.143 s
T90_start 18:48:38.062 UTC
fluence 5.47e-05 erg/cm²
fluence_error 5.87e-08 erg/cm²
flux_1024 6.49e+01 erg/cm²/s
flux_1024_error 3.88e-01 erg/cm²/s
flux_1024_time 1.15e+00 erg/cm²/s
flux_64 1.48e+02 erg/cm²/s
flux_64_error 2.13e+00 erg/cm²/s
GCN 8671 table
GRB_name GRB081215A
GCN_number 8671
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 8671 SUBJECT: GRB 081215A: Andromeda inside Fermi error box: MASTER observations DATE: 08/12/15 19:27:12 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs E. Gorbovskoy, V. Lipunov, V.Kornilov, A.Belinski, N.Shatskiy, N.Tyurina, D.Kuvshinov, P.Balanutsa Sternberg Astronomical Institute, Moscow State University A. Tlatov, A.V. Parhomenko Kislovodsk Solar Station of the Pulkovo Observatory V.Krushinski, I.Zalognikh Ural State University, Kourovka S.Yazev, K.Ivanov Irkutsk State University One of the four MASTER Very Wide Field Cameras located at Kislovodsk (http://apollo.sai.msu.ru/, D=50 mm, 4x1000 square degrees, 35'' per pix) has observed Fermi error box (Trig Num 251059717) with 5s exposures during all night without time gap between images. The M31 (ANdromeda) is inside Fermi error box. The message may be cited. mailto: lipunov@sai.msu.ru
GCN 8673 table
GRB_name GRB081215A
GCN_number 8673
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 8673 SUBJECT: GRB 081215A: Gamma Repeater? DATE: 08/12/15 20:32:18 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, If the GRB 081215A really connected with M31 (Gorbovskoy et al, GCN Circ 8671, 8672) it must be Soft Gamma Repeater or Andromeda X-ray binary source. The message may be cited. mailto: lipunov@sai.msu.ru
GCN 8678 table
GRB_name GRB081215A
GCN_number 8678
Detection_method Fermi GBM Det
t_trigger 18:48:36.850 UTC
ra 135.0000°
decl 53.8000°
Circular_text TITLE: GCN CIRCULAR NUMBER: 8678 SUBJECT: GRB 081215A: Fermi GBM detection DATE: 08/12/17 22:42:55 GMT FROM: Rob Preece at UAH Robert Preece (UAH) reports on behalf of the Fermi GBM Team: "At 18:48:36.85 UT on 15 December 2008, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 081215 (trigger 251059717 / 081215784). The on-ground calculated location, using the GBM trigger data, is RA = 135.0, DEC = +53.8 (J2000 degrees, equivalent to 09 h 00 m 00.00, 53 d 48 '), with an uncertainty of 1.0 degrees (radius, 1-sigma containment, statistical only; there is additionally a systematic error which is currently estimated to be 2 to 3 degrees). The angle from the Fermi LAT boresight is 86 degrees. The on-board GBM Flight Software localization for this very bright burst, as reported in the GCN Notices, was consistent with a position on the Earth's surface, likely due to a large scattered flux from the Earth. This resulted in an autonomous and erroneous "100% Below horizon" classification for this event which prevented an automated ground localization from being sent through the GCN notice system. The GBM light curve consists of a very hard narrow pulse on top of a broader emission episode, with a duration (T90) of about 7.7 s (8-1000 keV). The time-averaged spectrum from T0-1.79 s to T0+13.57 s is best fit by a Band function with Epeak = 304 +/- 11 keV, alpha = -0.585 +/- 0.022, and beta = -2.066 +/- 0.038. The event fluence (8-1000 keV) in this time interval is (3.54 +/- 0.05)E-6 erg/cm^2. The 1-sec photon flux measured starting from T0+1.28 s in the 8-1000 keV band is 68.9 +/- 1.0 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN 8679 table
GRB_name GRB081215A
GCN_number 8679
Detection_method correction
Circular_text TITLE: GCN CIRCULAR NUMBER: 8679 SUBJECT: GRB 081215A: Fermi GBM detection (correction to event fluence) DATE: 08/12/18 17:05:04 GMT FROM: Rob Preece at UAH Robert Preece (UAH) reports on behalf of the Fermi GBM Team: "The correct event fluence for the GRB detection reported in Circular Number 8678 should be: (5.44 +/- 0.07)E-5 erg/cm^2 in the energy interval 8-1000 kev for times -T0-1.79 s to T0+13.57 s. Thanks to Alexander Kann at TLS Tautenburg for spotting the error."
GCN 8684 table
GRB_name GRB081215A
GCN_number 8684
Detection_method Fermi LAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 8684 SUBJECT: GRB081215A: Fermi-LAT observations DATE: 08/12/19 17:34:59 GMT FROM: Julie McEnery at UMBC/GSFC Julie McEnery (NASA/GSFC) reports on behalf of the Fermi LAT team We report a detection by the Fermi Large Area Telescope (LAT) of emission from GRB081215A (Preece et al, GCN8678). This burst was at an angle of 86 degrees to the LAT boresight, which means that neither directional nor energy information can be obtained with the standard analysis procedures. Using a non-standard data selection, over 100 counts above background were detected within a 0.5 s interval in coincidence with the main GBM peak. The significance of this excess was greater than 8 sigma. A preliminary study of the instrument performance at such a large inclination suggests that these events are likely to be low energy gamma-rays, with energies less than 200 MeV. Further analysis is ongoing. The Fermi LAT point of contact for this burst is Julie McEnery (julie.mcenery@nasa.gov). The Fermi LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden. This message can be cited.
GCN 8702 table
GRB_name GRB081215A
GCN_number 8702
Detection_method IPN Triangulation
ra 78.2010°
decl 17.5750°
Circular_text TITLE: GCN CIRCULAR NUMBER: 8702 SUBJECT: IPN triangulation of bright GRB 081215A DATE: 08/12/22 14:41:25 GMT FROM: Valentin Pal'shin at Ioffe Inst S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, T. Cline, and K. Hurley on behalf of the Konus-Wind team, M. Marisaldi, F. Fuschino, I. Donnarumma, E. Del Monte and M. Feroci on behalf of the AGILE Team, J. Cummings, S. Barthelmy, N. Gehrels, and H. Krimm, on behalf of the Swift-BAT team, report: AGILE-MCAL and Konus-Wind observed the very bright GRB 081215A at about 18:48:38 UT (corresponds to the Fermi/GBM trigger 251059717 / 081215784: Preece, GCN 8678, 8679). The burst was outside the coded field of view of the SuperAGILE. The burst light curve shows a multipeaked structure with a total duration of ~10 sec. The Swift-BAT saw nothing at this time. Hence, taking in account the high intensity of this GRB, that means the source of the burst was below the horizon for Swift. Triangulation gives an annulus centered at RA(2000)=78.201 (05h 12m 48s) Dec(2000)=+17.575 (+17d 34' 32"), whose radius is 51.547 0.508 deg (3sigma). The Fermi/GBM ground position (Preece, GCN 8678) is 5 deg away from the center line of the annulus. The Konus ecliptic latitude response constrains the arrival direction to a band between ecliptic latitudes +30 and +53 degrees. Combining all these data, we have triangulated this burst to a single error box, whose corners are: ----------------------------------------------------- RA(2000), deg Dec(2000), deg ----------------------------------------------------- 1: 129.016 (08h 36m 04s) +50.756 (+50d 45' 22") 2: 122.577 (08h 10m 18s) +58.308 (+58d 18' 28") 3: 121.670 (08h 06m 41s) +57.174 (+57d 10' 27") 4: 127.051 (08h 28m 12s) +51.125 (+51d 07' 32") ----------------------------------------------------- Preliminary analysis of the Konus-Wind data yields a burst fluence of ~7x10^-5 erg/cm2 (in the 20 keV - 5 MeV range), and an Epeak of the time-integrated spectrum of ~450 keV. Detailed spectral parameters will be reported later. The K-W light curve of this GRB and IPN triangulation map is available at http://www.ioffe.ru/LEA/GRBs/GRB081215_T67721/
GCN 8706 table
GRB_name GRB081215A
GCN_number 8706
Detection_method Konus-Wind Det
t_trigger 18:48:41.281 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 8706 SUBJECT: Konus-Wind observation of very bright GRB 081215A DATE: 08/12/22 16:19:07 GMT FROM: Valentin Pal'shin at Ioffe Inst S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report: The very bright GRB 081215A (Fermi/GBM trigger 251059717 / 081215784: Preece, GCN 8678, 8679) localized by IPN (Golenetskii et al., GCN 8702) triggered Konus-Wind at T0=67721.281 s UT (18:48:41.281). As observed by Konus-Wind the burst had a fluence of (7.99 +/- 0.68)x10^-5 erg/cm2, and a 16-ms peak flux measured from T0+0.448 s of (1.24 +/- 0.17)x10^-4 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum of the burst (from T0 to T0+12.544 s) is well be fitted (in the 20 keV - 5 MeV range) by GRB (Band) model for which: the low-energy photon index is alpha = -0.870(-0.064, +0.070), the high energy photon index beta = -2.20(-0.19, +0.13), the peak energy Ep = 447(-52, +60) keV (chi2 = 72.2/76 dof). The spectrum of the most intense peak (from T0+0.256 s to T0+0.512 s) is well fitted (in the 20 keV-10 MeV range) by GRB (Band) model for which: the low-energy photon index is alpha = -0.49(-0.10, +0.12), the high energy photon index beta = -2.38(-0.37, +0.23), the peak energy Ep = 1001(-174, +193) keV (chi2 = 57.5/58 dof). In this spectrum a statistically significant emission is clearly seen up to 10 MeV. All the quoted errors are at the 90% confidence level. [GCN OPS NOTE(23dec08): Per author's request, "2.38(-0.37, +0.23)" was changed to "-2.38(-0.37, +0.23)".]
GCN 11574 table
GRB_name GRB081215A
GCN_number 11574
Detection_method Fermi GBM Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 11574 SUBJECT: New feature in Fermi GBM GRB Ground Position Notices DATE: 11/01/17 04:19:13 GMT FROM: Valerie Connaughton at UAH/NSSTC Valerie Connaughton reports for the Fermi GBM Team: As of today, new information has been added to the GBM Ground Location GCN notices (GCN/FERMI_GBM_GND_POSITION) that will alert observers that a bright, hard burst has occurred in the LAT field-of-view. This additional information is derived from the limited real-time data extracted by the flight software, telemetered to the ground, and used to calculate the automated on-ground burst locations currently distributed in the notice within seconds - tens of seconds of the burst trigger. Background-subtracted count rates above 200 keV registered in the BGO detectors for events localized within 70 deg of the LAT boresight are used to flag the event. This is done for each of the localizations performed on the ground, so that it is possible that an event can be flagged as interesting in one notice and not in another, owing to brightness variations and spectral evolution in the burst. The background measure and integration time for the data provide less information than is available after the full data download hours later, so the method is not completely reliable, but it is fast and should permit observers to dedicate more effort to following up the sub-set of events that contains the LAT-detected burst population. The identification technique is susceptible to false positives in the case of short bursts, which can be mistakenly identified as bright owing to short integration times being more susceptible to statistical fluctuations above backgrounds measured in a fairly crude automated fashion. We have attempted to mitigate this by penalizing information obtained from integration times shorter than 64 ms, while still retaining the brighter short bursts. We have set a threshold which would have flagged 13 of the 18 high-confidence LAT detections between July 2008 and December 2010, with an additional 24 flagged events that are not high-confidence LAT detections (though some are low-confidence LAT detections). By lowering the threshold, we can identify all but two of the LAT high-confidence detections (GRB081215 was seen at 90 deg off-axis, and GRB100116 triggered on a precursor with the main, LAT-detected emission occurring 80 seconds later, beyond the time when the GBM FSW passes on the information for localization). Lowering the threshold this way comes at a cost of flagging 81 additional bursts (out of a total 575 GBM GRBs). Our thresholds can easily be altered upon feedback from the community. Statistical uncertainties on these types of localizations can be as low as 1 deg. An additional systematic error is associated with our localizations. Based on a study using 150 GRBs localized by other instruments (LAT, Swift BAT, SuperAGILE, INTEGRAL, MAXI, the InterPlanetary Network), this additional uncertainty is 3.2 deg for 70% of the automated ground locations distributed in these notices, and 9.5 deg for the remaining 30% (Briggs et al., in preparation). The GBM team is working to reduce these uncertainties. Please address feedback and questions tovalerie@nasa.gov