Swift Observations of GRB 221009A

J.A. Kennea (PSU) and N.P.M. Kuin (UCL-MSSL) for the Swift team

1. Introduction

Kennea and Williams (GCN Circ. 32635) reported the initial Swift results. We provide an update on the BAT trigger 1126853, AKA Swift J1913.1+1946 (GCN Circ. 32632). At the time of the trigger, the initial BAT position was 95° from the Sun (6.2 hours East) and 84° from the 100%-illuminated Moon. Table 1 contains the best reported positions from Swift, and the latest XRT position can be viewed at http://www.swift.ac.uk/xrt_positions.

Lipunov et al. (GCN Circ. 32634) reported the position from MASTER for the optical afterglow of this GRB. Kuin and Dichiara (GCN Circ. 32656) reported the detection with UVOT of an optical afterglow. de Ugarte Postigo et al. (GCN Circ. 32648) determined a redshift of 0.151 from VLT, Castro-Tirado et al. (GCN Circ. 32686) determined a redshift of 0.1505 from GTC, and Izzo et al. (GCN Circ. 32765) determined a redshift of 0.151 from VLT. Table 2 is a summary of GCN Circulars about this GRB from observatories other than Swift.

Standard analysis products for this burst are available at https://gcn.gsfc.nasa.gov/swift_gnd_ana.html.

2. BAT Observations and Analysis

As reported by Krimm et al. (GCN Circ. 32688), the BAT ground-calculated position is RA, Dec = 288.254, 19.809 deg which is RA(J2000) = 19^h13^m00.9^s Dec(J2000) = +19°48'34.1" with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 9%.

The mask-weighted light curve (Figure 1) shows a flat and long-lasting emission that may have started before the burst came into the BAT FOV at T-26 s. The burst emission seems to end at ~T+1320 s, however, we cannot rule out the possibility that the emission extends beyond the available event data that end at T+1371 s. The lower limit of T₉₀ (15-350 keV) is 1068.40 ± 13.34 s (estimated error including systematics).

The time-averaged spectrum from T+103.3 s to T+1338.7 s s is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.08 ± 0.03. The fluence in the 15-150 keV band is 7.4 ± 0.1 x 10^-5 erg cm^-2. This fluence is larger than that of 99.5% of the long GRBs in the Second BAT GRB Catalog (Sakamoto et al. 2011). The 1-s peak photon flux measured from T+776.47 s in the 15-150 keV band is 1.9 ± 0.3 ph cm^-2 s^-1. All the quoted errors are at the 90% confidence level.

The results of the batgrbproduct analysis are available at https://gcn.gsfc.nasa.gov/notices_s/1126853/BA/.

3. XRT Observations and Analysis

Analysis of the initial XRT data was reported by Kennea et al. (GCN Circ. 32651). We have analysed 277 ks of XRT data for GRB 221009A (E Bissaldi et al. GCN Circ. 32637), from 174 s to 5176.4 ks after the BAT trigger. The data comprise 16 ks in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode.

The late-time light curve (Figure 2) (from T0+18.4 ks) can be modelled with a series of power-law decays. The initial decay index is α=1.519 ± 0.004. At T+42.0 ks the decay flattens to an α of 0.9 (+0.5, -0.8). The light curve breaks again at T+45.4 ks to a decay with α=1.730 ± 0.015, again at T+441 ks s to α=-0.2 (+1.1, -1.3), and again at T+512 ks s to α=1.90 (+0.10, -0.07), before a final break at T+1745 ks s after which the decay index is 1.10 ± 0.16.

A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.806 ± 0.011. The best-fitting absorption column is 6.70 (+0.16, -0.15) x 10²¹ cm^-2, at a redshift of 0.151, in addition to the Galactic value of 5.4 x 10²¹ cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.79 (+0.20, -0.19) and a best-fitting absorption column of 7.6 (+2.9, -2.6) x 10²¹ cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 6.2 x 10^-11 (1.1 x 10^-10) erg cm^-2 count^-1.

A summary of the PC-mode spectrum is thus:
Galactic foreground: 5.4 x 10²¹ cm^-2
Intrinsic column: 7.6 (+2.9, -2.6) x 10²¹ cm^-2 at z=0.151
Photon index: 1.79 (+0.20, -0.19)

The results of the XRT team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01126853.

4. UVOT Observations and Analysis

Analysis of the UVOT data was reported by Kuin and Dichiara (GCN Circ. 32656). Table 3 gives preliminary magnitudes using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc., 1358, 373). No correction has been made for the expected extinction in the Milky Way corresponding to a reddening of E_B-V of 1.563 mag. in the direction of the GRB (Schlegel et al. 1998).

BAT light curve

Figure 1. The BAT mask-weighted light curve in the four individual and total energy bands. The units are counts s^-1 illuminated-detector^-1. The vertical green dash-dotted lines show the T₅₀ interval, the vertical black dashed lines show the T₉₀ interval, and vertical blue (orange) solid lines show the start (stop) of slews.

XRT light curve

Figure 2. The XRT light curve. Any data from a crosshatched region are not included in the fit.

RA (J2000) Dec (J2000) Error Note Reference

19^h13^m03.48^s +19°46'24.6" 0.61" UVOT GCN Circ. 32632

19^h13^m03.43^s +19°46'16.3" 5.6" XRT ?

19^h13^m00.9^s +19°48'34.1" 2.4' BAT-refined Krimm et al. GCN Circ. 32688

Table 1. Positions from the Swift instruments.

Band Authors GCN Circ. Subject Observatory Notes

Optical Lipunov et al. 32634 Swift GRB221009.59: Global MASTER-Net
OT detection MASTER detection

Optical Hu et al. 32644 BOOTES-2/TELMA and OSN optical
detections BOOTES-2 detection

Optical Belkin et al. 32645 (Swift J1913.1+1946): Mondy optical
observations Mondy detection

Optical de Wet and Groot 32646 (Swift J1913.1+1946): MeerLICHT
observations MeerLICHT

Optical Xu et al. 32647 Nanshan/NEXT photometry and
Xinglong-2.16m spectroscopy Xinjiang Astro. Obs. spectroscopy

Optical de Ugarte Postigo et al. 32648 Redshift from X-shooter/VLT VLT redshift

Optical Brivio et al. 32652 REM optical and NIR detection of the
afterglow REM detection

Optical Durbak et al. 32654 or Swift J1913.1+1946: PRIME
near-infrared detection detection

Optical Paek et al. 32659 GRB 221009A: Multi-color detection
of the optical LOAO detection

Optical Kumar et al. 32662 Swift J1913.1+1946: GIT detection of
the optical afterglow GROWTH-India Tel. detection

Optical F. Romanov 32664 (Swift J1913.1+1946): Burke-Gaffney
Observatory optical observations Burke-Gaffney Obs.

Optical Chen et al. 32667 Lulin SLT-40cm optical observations Lulin

Optical Vidal et al. 32669 Swift J1913.1+1946: Lick/Nickel
telescope optical observations KAIT detection

Optical Kim et al. 32670 Swift J1913.1+1946: Assy optical
afterglow observation Assy-Turgen Obs. detection

Optical Groot et al. 32678 BlackGEM optical observations detection

Optical F. Romanov 32679 (Swift J1913.1+1946): iTelescope
optical observation iTelescope

Optical Belkin et al. 32684 Sintez-Newton/CrAO optical observations CrAO detection

Optical Castro-Tirado et al. 32686 10.4m GTC spectroscopic redshift
confirmation GTC redshift

Optical Watson et al. 32692 COATLI Detection of the Afterglow COATLI detection

Optical Strausbaugh and Cucchiara 32693 LCOGT Optical Afterglow Detection Las Cumbres Obs. Global Tele.Network detection

Optical Butler et al. 32705 COATLI Continued Monitoring of the
Afterglow COATLI

Optical Vinko et al. 32709 optical afterglow measurements from
Konkoly Observatory Konkoly detection

Optical Mao et al. 32727 GMG observation Gao-Mei-Gu

Optical Zaznobin et al. 32729 Sayan observatory 1.6-m telescope
observations Sayan Obs.

Optical Sasada et al. 32730 MITSuME Okayama optical observation MITSuME Okayama

Optical Strausbaugh and Cucchiara 32738 LCOGT Continued Observations - Optical
Upper Limits Las Cumbres Obs. Global Tele.Network upper limits

Optical O'Connor et al. 32739 Lowell Discovery Telescope Afterglow
Detection Lowell Discovery Telescope detection

Optical Bikmaev et al. 32743 RTT-150 optical observations

Optical Rastinejad and Fong 32749 Gemini-South Optical Afterglow Detection Gemini detection

Optical O'Connor et al. 32750 Gemini-South Infrared Afterglow
Detection Gemini detection

Optical Bikmaev et al. 32752 RTT-150 optical observations light curve

Optical Schneider et al. 32753 OHP optical observations

Optical D’Avanzo et al. 32755 continued REM optical/NIR observations
and evidence for an achromatic
steepening in the afterglow light curve REM light curve

Optical Huber et al. 32758 Pan-STARRS optical photometry Pan-STARRS

Optical Shrestha et al. 32759 Large Binocular Telescope Observatory
optical afterglow detection Gemini detection

Optical Izzo et al. 32765 VLT spectroscopic detection of the host
galaxy VLT

Optical Belkin et al. 32769 continued Assy optical afterglow
observations, possible SN evidence Assy-Turgen Obs. light curve

Optical Shrestha et al. 32771 Faulkes Telescope North continued
optical afterglow follow-up FTN detection

Optical Rajabov et al. 32795 GRANDMA observations GRANDMA

Optical O'Connor et al. 32799 Continued LDT Afterglow Monitoring Lowell Discovery Telescope detection

Optical Im et al. 32803 BOAO NIR detections BOAO detection

Optical Ferro et al. 32804 TNG NIR detection TNG detection

Optical Rossi et al. 32809 LBT optical imaging LBT detection

Optical Gupta et al. 32811 1.3m DFOT Optical Observations DFOT detection

Optical Belkin et al. 32818 optical observations, SN photometric
evidence Assy-Turgen Obs. detection

Optical Levan et al. 32821 James Webb Space Telescope Observations James Webb detection

Optical Maiorano et al. 32850 spectroscopic confirmation of SN in LBT
spectra LBT

Optical Pellegrin and Rumstay 32852 SARA-RM 1m Optical Afterglow Detection SARA detection

Optical O'Connor et al. 32860 Further Gemini-South Infrared
Observations Gemini detection

Optical Pellegrin and Rumstay 32912 Correction to GCN Circ. 32852 (GRB 221009A:
SARA-RM 1m Optical Afterglow Detection) SARA detection

Optical Levan et al. 32921 Hubble Space Telescope observations Hubble Space Telescope detection

Optical Aguerre et al. 32934 GRANDMA/Kilonova-Catcher observations GRANDMA

Optical de Wet 32944 Correction to GCN Circ. 32646 (GRB 221009A
(Swift J1913.1+1946): MeerLICHT
observations) MeerLICHT

Optical Lindfors et al. 32995 Optical polarization observation NOT

Radio Bright et al. 32653 Swift J1913.1+1946: AMI-LA observations AMI

Radio de Ugarte Postigo et al. 32676 NOEMA mm detection NOEMA detection

Radio Rhodes et al. 32707 Swift J1913.1+1946: SMA observations SMA

Radio Laskar et al. 32740 MeerKAT detection MeerKAT detection

Radio Laskar et al. 32757 VLA detection VLA detection

Radio Urata et al. 32761 ALMA and ACA detections ALMA detection

Radio Bhandari et al. 32763 ATCA detection ATCA detection

Radio Leung et al. 32766 ATCA radio spectrum ATCA detection

Radio Marongiu et al. 32791 Medicina Radio Telescope observations Medicina Radio

Radio Atri et al. 32907 High-precision position of the compact
radio counterpart to GRB221009A VLBA detection

Radio Niinuma et al. 32949 Japanese VLBI Network observation VLBI

X-ray Negro 32690 planned observation with the Imaging
X-ray Polarimetry Explorer (IXPE) plans

X-ray Brethauer et al. 32695 NuSTAR Detection NuSTAR detection

X-ray Manfreda 32754 IXPE preliminary upper limits of X-ray
polarization upper limits

X-ray Kobayashi et al. 32756 MAXI/GSC refined analysis of the
bright X-ray afterglow of GRB
221009A/Swift J1913.1+1946 MAXI

X-ray Liu et al. 32767 LEIA X-ray Afterglow Detection detection

X-ray Brethauer et al. 32788 Second epoch of NuSTAR data NuSTAR

X-ray Aimuratov et al. 32802 X-ray light-curve and the indication of
TeV light-curve

Gamma-ray Veres et al. 32636 Fermi GBM detection of an
extraordinarily bright GRB Fermi GBM

Gamma-ray Bissaldi et al. 32637 or Swift J1913.1+1946: Fermi-LAT
detection Fermi LAT E_max=7.8 GeV

Gamma-ray Svinkin et al. 32641 IPN triangulation of extremely bright
GRB 221009A IPN

Gamma-ray Lesage et al. 32642 Fermi GBM observation Fermi GBM E_peak=375±87 keV
T₉₀=327 seconds
Fluence=2.12±0.05x10^-5erg cm^-2
(brighter than 88% of long GRBs)

Gamma-ray Ursi et al. 32650 (Swift J1913.1+1946): AGILE/MCAL
detection AGILE

Gamma-ray Piano et al. 32657 (Swift J1913.1+1946): AGILE/GRID
detection AGILE

Gamma-ray Pillera et al. 32658 Fermi-LAT refined analysis Fermi LAT

Gamma-ray Gotz et al. 32660 Swift J1913.1+1946: INTEGRAL SPI/ACS
observations INTEGRAL

Gamma-ray Lapshov et al. 32663 Swift J1913.1+1946: SRG/ART-XC
observation SRG/ART

Gamma-ray Frederiks et al. 32668 Konus-Wind detection Konus-Wind E_peak=975 (-332,+712) keV

Gamma-ray Huang et al. 32677 LHAASO observed GRB 221009A with more
than 5000 VHE photons up to around 18
TeV LHAASO

Gamma-ray Ayala et al. 32683 Upper limits from HAWC 8 hours after
trigger HAWC

Gamma-ray Ripa et al. 32685 Detection by GRBAlpha GRBAlpha

Gamma-ray Savchenko et al. 32691 INTEGRAL detection of Hard X-ray
emission up to 38 hours after trigger INTEGRAL

Gamma-ray Mitchell et al. 32746 Gamma-ray Detection by SIRI-2 SIRI-2

Gamma-ray Xia et al. 32748 a 397.7 GeV photon observed by
Fermi-LAT at 0.4 day after the GBM
trigger Fermi GBM

Gamma-ray Liu et al. 32751 HEBS detection HEBS

Gamma-ray Omodei et al. 32760 Fermi LAT data rate effects due to
extremely high flux Fermi LAT

Gamma-ray Kozyrev et al. 32805 Improved IPN localization for GRB
221009A (BepiColombo-MGNS light curve) IPN

Gamma-ray Minaev et al. 32819 Analysis of the initial episode using
data of GBM/Fermi and SPI-ACS/INTEGRAL Fermi GBM E_peak=375±87 keV

Gamma-ray Omodei et al. 32916 Extended Bad Time Intervals for Fermi
LAT data Fermi LAT

Gamma-ray Laboratory 32973 ：DAMPE observed a 34.7 GeV p DAMPE

Neutrino Collaboration 32665 Upper limits from a neutrino search
with IceCube IceCube upper limits

Neutrino Collaboration 32741 search for neutrinos with KM3NeT

Other Schnoor et al. 32744 Detection as sudden ionospheric
disturbances (SID) detection

Other Guha and Nicholson 32745 Ionospheric disturbance observed in
India

Other Kann and Fernandez 32762 Armchair Energetics light curve

Other Aimuratov et al. 32780 A type I BdHN of exceptional energetics

Other J. Atteia 32793 The probability of observing GRB
221009A at z = 0.151 redshift

Other de Ugarte Postigo et al. 32800 Spectroscopic detection of emerging SN
features

Other Aimuratov et al. 32808 Peak luminosity of the supernova vs.
synchrotron afterglow

Other Aimuratov et al. 32828 Determination of the black holes mass
and spin

Other of the LIGO and Virgo 32877 LIGO-Virgo-KAGRA and GEO600 statement
on GRB 221009A

Other Kimura et al. 33038 MuSCAT3 observations light curve

Table 2. Summary of GCN Circulars from other observatories sorted by band and then circular number.

Filter T_start(s) T_stop(s) Exp(s) Mag

white 179 329 147 16.68 ± 0.03

v 668 688 20 15.55 ± 0.10

b 593 613 20 17.05 ± 0.11

u 337 587 246 17.68 ± 0.06

w1 718 1293 58 >18.2

w2 817 1219 39 >19.1

RA (J2000)	Dec (J2000)	Error	Note	Reference
19^h13^m03.48^s	+19°46'24.6"	0.61"	UVOT	GCN Circ. 32632
19^h13^m03.43^s	+19°46'16.3"	5.6"	XRT	?
19^h13^m00.9^s	+19°48'34.1"	2.4'	BAT-refined	Krimm et al. GCN Circ. 32688

Band	Authors	GCN Circ.	Subject	Observatory	Notes
Optical	Lipunov et al.	32634	Swift GRB221009.59: Global MASTER-Net OT detection	MASTER	detection
Optical	Hu et al.	32644	BOOTES-2/TELMA and OSN optical detections	BOOTES-2	detection
Optical	Belkin et al.	32645	(Swift J1913.1+1946): Mondy optical observations	Mondy	detection
Optical	de Wet and Groot	32646	(Swift J1913.1+1946): MeerLICHT observations	MeerLICHT
Optical	Xu et al.	32647	Nanshan/NEXT photometry and Xinglong-2.16m spectroscopy	Xinjiang Astro. Obs.	spectroscopy
Optical	de Ugarte Postigo et al.	32648	Redshift from X-shooter/VLT	VLT	redshift
Optical	Brivio et al.	32652	REM optical and NIR detection of the afterglow	REM	detection
Optical	Durbak et al.	32654	or Swift J1913.1+1946: PRIME near-infrared detection		detection
Optical	Paek et al.	32659	GRB 221009A: Multi-color detection of the optical	LOAO	detection
Optical	Kumar et al.	32662	Swift J1913.1+1946: GIT detection of the optical afterglow	GROWTH-India Tel.	detection
Optical	F. Romanov	32664	(Swift J1913.1+1946): Burke-Gaffney Observatory optical observations	Burke-Gaffney Obs.
Optical	Chen et al.	32667	Lulin SLT-40cm optical observations	Lulin
Optical	Vidal et al.	32669	Swift J1913.1+1946: Lick/Nickel telescope optical observations	KAIT	detection
Optical	Kim et al.	32670	Swift J1913.1+1946: Assy optical afterglow observation	Assy-Turgen Obs.	detection
Optical	Groot et al.	32678	BlackGEM optical observations		detection
Optical	F. Romanov	32679	(Swift J1913.1+1946): iTelescope optical observation	iTelescope
Optical	Belkin et al.	32684	Sintez-Newton/CrAO optical observations	CrAO	detection
Optical	Castro-Tirado et al.	32686	10.4m GTC spectroscopic redshift confirmation	GTC	redshift
Optical	Watson et al.	32692	COATLI Detection of the Afterglow	COATLI	detection
Optical	Strausbaugh and Cucchiara	32693	LCOGT Optical Afterglow Detection	Las Cumbres Obs. Global Tele.Network	detection
Optical	Butler et al.	32705	COATLI Continued Monitoring of the Afterglow	COATLI
Optical	Vinko et al.	32709	optical afterglow measurements from Konkoly Observatory	Konkoly	detection
Optical	Mao et al.	32727	GMG observation	Gao-Mei-Gu
Optical	Zaznobin et al.	32729	Sayan observatory 1.6-m telescope observations	Sayan Obs.
Optical	Sasada et al.	32730	MITSuME Okayama optical observation	MITSuME Okayama
Optical	Strausbaugh and Cucchiara	32738	LCOGT Continued Observations - Optical Upper Limits	Las Cumbres Obs. Global Tele.Network	upper limits
Optical	O'Connor et al.	32739	Lowell Discovery Telescope Afterglow Detection	Lowell Discovery Telescope	detection
Optical	Bikmaev et al.	32743	RTT-150 optical observations
Optical	Rastinejad and Fong	32749	Gemini-South Optical Afterglow Detection	Gemini	detection
Optical	O'Connor et al.	32750	Gemini-South Infrared Afterglow Detection	Gemini	detection
Optical	Bikmaev et al.	32752	RTT-150 optical observations		light curve
Optical	Schneider et al.	32753	OHP optical observations
Optical	D’Avanzo et al.	32755	continued REM optical/NIR observations and evidence for an achromatic steepening in the afterglow light curve	REM	light curve
Optical	Huber et al.	32758	Pan-STARRS optical photometry	Pan-STARRS
Optical	Shrestha et al.	32759	Large Binocular Telescope Observatory optical afterglow detection	Gemini	detection
Optical	Izzo et al.	32765	VLT spectroscopic detection of the host galaxy	VLT
Optical	Belkin et al.	32769	continued Assy optical afterglow observations, possible SN evidence	Assy-Turgen Obs.	light curve
Optical	Shrestha et al.	32771	Faulkes Telescope North continued optical afterglow follow-up	FTN	detection
Optical	Rajabov et al.	32795	GRANDMA observations	GRANDMA
Optical	O'Connor et al.	32799	Continued LDT Afterglow Monitoring	Lowell Discovery Telescope	detection
Optical	Im et al.	32803	BOAO NIR detections	BOAO	detection
Optical	Ferro et al.	32804	TNG NIR detection	TNG	detection
Optical	Rossi et al.	32809	LBT optical imaging	LBT	detection
Optical	Gupta et al.	32811	1.3m DFOT Optical Observations	DFOT	detection
Optical	Belkin et al.	32818	optical observations, SN photometric evidence	Assy-Turgen Obs.	detection
Optical	Levan et al.	32821	James Webb Space Telescope Observations	James Webb	detection
Optical	Maiorano et al.	32850	spectroscopic confirmation of SN in LBT spectra	LBT
Optical	Pellegrin and Rumstay	32852	SARA-RM 1m Optical Afterglow Detection	SARA	detection
Optical	O'Connor et al.	32860	Further Gemini-South Infrared Observations	Gemini	detection
Optical	Pellegrin and Rumstay	32912	Correction to GCN Circ. 32852 (GRB 221009A: SARA-RM 1m Optical Afterglow Detection)	SARA	detection
Optical	Levan et al.	32921	Hubble Space Telescope observations	Hubble Space Telescope	detection
Optical	Aguerre et al.	32934	GRANDMA/Kilonova-Catcher observations	GRANDMA
Optical	de Wet	32944	Correction to GCN Circ. 32646 (GRB 221009A (Swift J1913.1+1946): MeerLICHT observations)	MeerLICHT
Optical	Lindfors et al.	32995	Optical polarization observation	NOT
Radio	Bright et al.	32653	Swift J1913.1+1946: AMI-LA observations	AMI
Radio	de Ugarte Postigo et al.	32676	NOEMA mm detection	NOEMA	detection
Radio	Rhodes et al.	32707	Swift J1913.1+1946: SMA observations	SMA
Radio	Laskar et al.	32740	MeerKAT detection	MeerKAT	detection
Radio	Laskar et al.	32757	VLA detection	VLA	detection
Radio	Urata et al.	32761	ALMA and ACA detections	ALMA	detection
Radio	Bhandari et al.	32763	ATCA detection	ATCA	detection
Radio	Leung et al.	32766	ATCA radio spectrum	ATCA	detection
Radio	Marongiu et al.	32791	Medicina Radio Telescope observations	Medicina Radio
Radio	Atri et al.	32907	High-precision position of the compact radio counterpart to GRB221009A	VLBA	detection
Radio	Niinuma et al.	32949	Japanese VLBI Network observation	VLBI
X-ray	Negro	32690	planned observation with the Imaging X-ray Polarimetry Explorer (IXPE)		plans
X-ray	Brethauer et al.	32695	NuSTAR Detection	NuSTAR	detection
X-ray	Manfreda	32754	IXPE preliminary upper limits of X-ray polarization		upper limits
X-ray	Kobayashi et al.	32756	MAXI/GSC refined analysis of the bright X-ray afterglow of GRB 221009A/Swift J1913.1+1946	MAXI
X-ray	Liu et al.	32767	LEIA X-ray Afterglow Detection		detection
X-ray	Brethauer et al.	32788	Second epoch of NuSTAR data	NuSTAR
X-ray	Aimuratov et al.	32802	X-ray light-curve and the indication of TeV light-curve
Gamma-ray	Veres et al.	32636	Fermi GBM detection of an extraordinarily bright GRB	Fermi GBM
Gamma-ray	Bissaldi et al.	32637	or Swift J1913.1+1946: Fermi-LAT detection	Fermi LAT	E_max=7.8 GeV
Gamma-ray	Svinkin et al.	32641	IPN triangulation of extremely bright GRB 221009A	IPN
Gamma-ray	Lesage et al.	32642	Fermi GBM observation	Fermi GBM	E_peak=375±87 keV T₉₀=327 seconds Fluence=2.12±0.05x10^-5erg cm^-2 (brighter than 88% of long GRBs)
Gamma-ray	Ursi et al.	32650	(Swift J1913.1+1946): AGILE/MCAL detection	AGILE
Gamma-ray	Piano et al.	32657	(Swift J1913.1+1946): AGILE/GRID detection	AGILE
Gamma-ray	Pillera et al.	32658	Fermi-LAT refined analysis	Fermi LAT
Gamma-ray	Gotz et al.	32660	Swift J1913.1+1946: INTEGRAL SPI/ACS observations	INTEGRAL
Gamma-ray	Lapshov et al.	32663	Swift J1913.1+1946: SRG/ART-XC observation	SRG/ART
Gamma-ray	Frederiks et al.	32668	Konus-Wind detection	Konus-Wind	E_peak=975 (-332,+712) keV
Gamma-ray	Huang et al.	32677	LHAASO observed GRB 221009A with more than 5000 VHE photons up to around 18 TeV	LHAASO
Gamma-ray	Ayala et al.	32683	Upper limits from HAWC 8 hours after trigger	HAWC
Gamma-ray	Ripa et al.	32685	Detection by GRBAlpha	GRBAlpha
Gamma-ray	Savchenko et al.	32691	INTEGRAL detection of Hard X-ray emission up to 38 hours after trigger	INTEGRAL
Gamma-ray	Mitchell et al.	32746	Gamma-ray Detection by SIRI-2	SIRI-2
Gamma-ray	Xia et al.	32748	a 397.7 GeV photon observed by Fermi-LAT at 0.4 day after the GBM trigger	Fermi GBM
Gamma-ray	Liu et al.	32751	HEBS detection	HEBS
Gamma-ray	Omodei et al.	32760	Fermi LAT data rate effects due to extremely high flux	Fermi LAT
Gamma-ray	Kozyrev et al.	32805	Improved IPN localization for GRB 221009A (BepiColombo-MGNS light curve)	IPN
Gamma-ray	Minaev et al.	32819	Analysis of the initial episode using data of GBM/Fermi and SPI-ACS/INTEGRAL	Fermi GBM	E_peak=375±87 keV
Gamma-ray	Omodei et al.	32916	Extended Bad Time Intervals for Fermi LAT data	Fermi LAT
Gamma-ray	Laboratory	32973	：DAMPE observed a 34.7 GeV p	DAMPE
Neutrino	Collaboration	32665	Upper limits from a neutrino search with IceCube	IceCube	upper limits
Neutrino	Collaboration	32741	search for neutrinos with KM3NeT
Other	Schnoor et al.	32744	Detection as sudden ionospheric disturbances (SID)		detection
Other	Guha and Nicholson	32745	Ionospheric disturbance observed in India
Other	Kann and Fernandez	32762	Armchair Energetics		light curve
Other	Aimuratov et al.	32780	A type I BdHN of exceptional energetics
Other	J. Atteia	32793	The probability of observing GRB 221009A at z = 0.151		redshift
Other	de Ugarte Postigo et al.	32800	Spectroscopic detection of emerging SN features
Other	Aimuratov et al.	32808	Peak luminosity of the supernova vs. synchrotron afterglow
Other	Aimuratov et al.	32828	Determination of the black holes mass and spin
Other	of the LIGO and Virgo	32877	LIGO-Virgo-KAGRA and GEO600 statement on GRB 221009A
Other	Kimura et al.	33038	MuSCAT3 observations		light curve

Filter	T_start(s)	T_stop(s)	Exp(s)	Mag
white	179	329	147	16.68 ± 0.03
v	668	688	20	15.55 ± 0.10
b	593	613	20	17.05 ± 0.11
u	337	587	246	17.68 ± 0.06
w1	718	1293	58	>18.2
w2	817	1219	39	>19.1

Table 3. UVOT observations reported by Kuin and Dichiara (GCN Circ. 32656). The start and stop times of the exposures are given in seconds since the BAT trigger. The preliminary detections and 3-σ upper limits are given. No correction has been made for extinction in the Milky Way.

December 10, 2022