GRB 240624A

N. J. Klingler (GSFC/UMBC/CRESSTII), K. L. Page (U Leicester) and
D. M. Palmer (LANL) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 06:01:09 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 240624A (trigger=1238732).  Swift did not slew to the location
due to an observing constraint.  The BAT on-board calculated location is 
RA, Dec 102.444, -6.543 which is 
   RA(J2000) = 06h 49m 47s
   Dec(J2000) = -06d 32' 36"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of about 5 sec.  The peak count rate
was ~2200 counts/sec (15-350 keV), at ~1 sec after the trigger. 

Due to a Sun observing constraint, Swift cannot slew to the BAT
position until 10:01 UT on 2024 August 15. There will thus be no XRT or
UVOT data for this trigger before this time. 

Burst Advocate for this burst is N. J. Klingler (noelklin AT umbc.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/)

The Fermi GBM team reports the detection of a likely LONG GRB

At 06:01:11.37 UT on 24 June 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 240624A (trigger 740901676/240624251).

The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 114.37, Dec = -11.05 (J2000 degrees, equivalent to J2000 7h 37m, -11d 3'),
with a statistical uncertainty of 12.59 degrees.

The angle from the Fermi LAT boresight is 91 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240624251/quicklook/glg_skymap_all_bn240624251.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240624251/quicklook/glg_healpix_all_bn240624251.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240624251/quicklook/glg_lc_medres34_bn240624251.gif"

V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),

D. Buckley
(South African Astronomical Observatory),

O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)

MASTER-SAAO robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 240624A ( Fermi GBM team, GCN 36745
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 ) errorbox  39761 sec after notice time and 39801 sec after trigger time at 2024-06-24 17:04:33 UT, with upper limit up to  15.4 mag. Observations started at twilight.  The observations began at zenith distance = 84 deg. The sun  altitude  is -16.8 deg. 

The galactic latitude b =  5 deg., longitude l = 228 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2505441

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

   39892 | 2024-06-24 17:04:33 |         MASTER-SAAO | (06h 49m 40.87s , -06d 32m 06.9s) |   C |   180 | 15.4 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.

V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),

D. Buckley
(South African Astronomical Observatory),

O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),

V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)

MASTER-SAAO robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in South Africa (South African Astronomical Observatory) was pointed to the Swift GRB 240624A ( N. J. Klingler et al., GCN 36743
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 ) errorbox  39782 sec after notice time and 39803 sec after trigger time at 2024-06-24 17:04:33 UT, with upper limit up to  15.4 mag. Observations started at twilight.  The observations began at zenith distance = 84 deg. The sun  altitude  is -16.8 deg. 

The galactic latitude b = -3 deg., longitude l = 219 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2505317

We obtain a following upper limits.  

Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

   39893 |         MASTER-SAAO |   C |   180 | 15.4 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.

C. de Barra (UCD) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team:

"At 06:01:11.37 UT on 24 June 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 240624A (trigger 740901676/240624251).
which was also detected by Swift BAT (N. J. Klingler et al. 2024, GCN 36743
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 ).
The Fermi GBM on-ground location is consistent with the Swift BAT position.

The angle from the Fermi LAT boresight is 83 degrees.

The GBM light curve consists of a single emission episode with a duration (T90)
of about 2 s (50-300 keV). The time-averaged spectrum
from T0-3.1 to T0+2.0 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -0.45 +/- 0.39 and the cutoff energy,
parameterized as Epeak, is 90 +/- 13 keV.

The event fluence (10-1000 keV) in this time interval is
(7.0 +/- 0.8)E-07 erg/cm^2. The 64-ms peak photon flux measured
starting from T0+0.38 s in the 10-1000 keV band is 6 +/- 1 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"

D. M. Palmer (LANL), S. D. Barthelmy (GSFC), R. Gupta (GSFC), H. A. Krimm
(NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC),
M. J. Moss (GSFC), T. Parsotan (GSFC), D. Sadaula (GSFC/UMBC), T. Sakamoto
(AGU) (i.e. the Swift-BAT team):

Using the data set from T-240 to T+962 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 240624A (trigger #1238732)
(Klingler et al., GCN Circ. 36743
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 ).
The BAT ground-calculated position is
RA, Dec = 102.473, -6.534 deg which is
   RA(J2000)  =  06h 49m 53.6s
   Dec(J2000) = -06d 32' 02.8"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 49%.

The mask-weighted light curve shows a main structure with some overlapping
pulses that starts at ~T-2 s and ends at ~T+6 s. The main peak occurs at
~T+1.5 s. T90 (15-350 keV) is 5.89 +- 2.25 sec (estimated error including
systematics).

The time-averaged spectrum from T-0.06 to T+7.04 sec is best fit by a power
law with an exponential cutoff.  This fit gives a photon index 0.07 +-
0.94, and Epeak of 78.3 +- 36.0 keV (chi squared 45.64 for 56 d.o.f.).  For
this model the total fluence in the 15-150 keV band is 4.5 +- 0.6 x 10^-7
erg/cm2 and the 1-sec peak flux measured from T+0.88 sec in the 15-150 keV
band is 2.2 +- 0.3 ph/cm2/sec.  A fit to a simple power law gives a photon
index of 1.33 +- 0.18 (chi squared 52.69 for 57 d.o.f.).  All the quoted
errors are at the 90% confidence level.

The results of the batgrbproduct analysis are available at
https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1238732