December 2024 - vsnet-grb-info - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-grb-info 36528] GRB 241129A: Fermi GBM Observation
by GCN Circulars 10 Dec '24

10 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38529 SUBJECT: GRB 241129A: Fermi GBM Observation DATE: 24/12/10 18:23:02 GMT FROM: rhamburg(a)usra.edu R. Hamburg (USRA) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 01:31:33.42 UT on 29 November 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 241129A (trigger 754536698/241129064), which was also detected by Swift/BAT-NITRATES (DeLaunay et al. 2024, GCN 38419). The Fermi GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight is 75 degrees. The GBM light curve consists of a multi-peaked emission episode with a duration (T90) of about 52 s (50-300 keV). The time-averaged spectrum from T0-2.0 to T0+22.5 s is best fit by a simple power law function with index -2.00 +/- 0.04. The event fluence (10-1000 keV) in this time interval is (2.6 +/- 0.1)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+0.26 s in the 10-1000 keV band is 2.1 +/- 0.2 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/" View this GCN Circular online at https://gcn.nasa.gov/circulars/38529. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36527] GRB 241209B: Swift/BAT-GUANO localization skymap of a burst
by GCN Circulars 10 Dec '24

10 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38528 SUBJECT: GRB 241209B: Swift/BAT-GUANO localization skymap of a burst DATE: 24/12/10 18:07:37 GMT FROM: Jimmy DeLaunay at Penn State <delauj2(a)gmail.com> James DeLaunay (PSU), Samuele Ronchini (PSU), Aaron Tohuvavohu (Caltech), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report: Swift/BAT did not localize GRB 241209B onboard (T0: 2024-12-09T03:56:20 UTC, SVOM/ECLAIRs and SVOM/GRM trig sb24120901 GCN 38478) The Fermi notice, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1). Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground. The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu 2022, ApJ, 941, 169), performed on the temporal window [T0-20 s, T0+20 s], detects the burst with a sqrt(TS) of 12.3 in a 0.512 s analysis time bin, starting at T0 - 0.0 s. Using the NITRATES analysis, parameter estimation was performed to obtain the localization of this burst in the form of a HEALPIX Multi-Order Coverage (MOC) skymap. This localization accounts for both statistical and systematic errors. More details in the creation and calibration of these maps will soon be published (DeLaunay et al. 2024. in prep) The 90% credible area is 9,116 deg2 and the 50% credible area is 1881 deg2. The integrated probability inside the coded field of view is 7%. The NITRATES skymap is consistent with the position from SVOM/ECLAIRs (GCN 38478) and the afterglow (SVOM/VT GCN 38516, Swift-XRT GCN 38525), with the position lying on the 20% credible region contour of the NITRATES skymap. A plot of the probability skymap can be viewed here: [skymap_plot](https://guano.swift.psu.edu/trigger_report?id=755409414/#:~:te… The probability skymap file can be downloaded from the link here [skymap_fits_file](https://guano.swift.psu.edu/files/755409414/0_n_PROBMAP) Instructions on how to read and manipulate this map can be found here: https://guano.swift.psu.edu/documentation More details about this burst can be found on the trigger report page here: https://guano.swift.psu.edu/trigger_report?id=755409414 GUANO is a fully autonomous, extremely low latency, spacecraft commanding pipeline designed for targeted recovery of BAT event mode data around the times of compelling astrophysical events to enable more sensitive GRB searches. A live reporting of Swift/BAT event data recovered by GUANO can be found at: https://www.swift.psu.edu/guano/ View this GCN Circular online at https://gcn.nasa.gov/circulars/38528. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36526] GRB 241209D: REM optical/NIR upper limits
by GCN Circulars 10 Dec '24

10 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38527 SUBJECT: GRB 241209D: REM optical/NIR upper limits DATE: 24/12/10 16:46:08 GMT FROM: Riccardo Brivio at INAF-OAB <riccardo.brivio(a)inaf.it> R.Brivio, M. Ferro, P. D’Avanzo, Y.-D. Hu, S. Covino, D. Fugazza (INAF-OAB) report on behalf of the REM team: We observed the field of GRB 241209D detected by Swift/BAT (Parsotan et al., GCN 38489) and Fermi/GBM (Fermi GBM team, GCN 38488) with the REM 60cm robotic telescope located at the ESO observatory of La Silla (Chile). The observations were carried in the g, r, i, z, J, H, K bands, starting on 2024 December 10 at 06:54:39 UT (i.e. 19.9 hours after the Swift trigger), and lasting for about 1 hour. From preliminary photometry we do not detect the optical counterpart (Ducoin et al., GCN 38505) in the optical and NIR images at the Swift-XRT enhanced position (Goad et al., GCN 38491) down to the following 3sigma magnitude upper limits: r > 20.3 (AB; calibrated against the PanSTARRS catalogue) at a mid-time of t - t0 = 20.4 hr after the trigger, J > 18.1 (Vega; calibrated against the 2MASS catalogue) at a mid-time of t - t0 = 20.5 hr after the trigger. View this GCN Circular online at https://gcn.nasa.gov/circulars/38527. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36525] Konus-Wind detection of GRB 241209D
by GCN Circulars 10 Dec '24

10 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38526 SUBJECT: Konus-Wind detection of GRB 241209D DATE: 24/12/10 14:55:58 GMT FROM: Anna Ridnaia at Ioffe Institute <ridnaia(a)mail.ioffe.ru> A. Ridnaia, D. Frederiks, A. Lysenko, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report: The long-duration GRB 241209D (Fermi-GBM detection: Fermi GBM team, GCN 38488; Malacaria & Meegan, GCN 38507; Swift-BAT detection: Parsotan et al., GCN 38489; AstroSat CZTI detection: Tembhurnikar et al., GCN 38518) was detected by Konus-Wind (KW) in the waiting mode. A Bayesian block analysis of the KW waiting mode data in the 20-300 keV band reveals a >13 sigma count rate increase in the interval from T0-2.0 s to T0+42.160 s where T0 = T0(BAT) = 10:59:45.649 UT. The KW light curve of this burst is available at http://www.ioffe.ru/LEA/GRBs/GRB241209D/ Modeling a time-integrated spectrum of the burst (from T0-2.0 s to T0+42.160 s) by a power law with exponential cutoff (CPL) model dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep): yields alpha = -1.16 (-0.37, +4.03) and Ep = 90(-12,+14) keV. The total burst fluence is 8.79(-0.87,+1.74)x10^-6 erg/cm^2, and the 2.944 s peak energy flux, measured from T0-2.0 s, is 5.86(-0.75,+1.25)x10^-7 erg/cm^2. (both in the 20 keV - 10 MeV energy range). All the quoted errors are estimated at the 68% confidence level. All the presented results are preliminary. View this GCN Circular online at https://gcn.nasa.gov/circulars/38526. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36524] GRB 241209B: Swift-XRT afterglow detection
by GCN Circulars 10 Dec '24

10 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38525 SUBJECT: GRB 241209B: Swift-XRT afterglow detection DATE: 24/12/10 14:36:15 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> M. A. Williams (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), M.G. Bernardini (INAF-OAB), E. Ambrosi (INAF-IASFPA) , M. Capalbi (INAF-IASFPA), S. Dichiara (PSU), J.A. Kennea (PSU) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the SVOM/ECLAIRs-detected burst GRB 241209B. We searched for X-ray sources in 3.1 ks of Photon Counting (PC) mode data. The total exposure at the position of the afterglow (see below) is 3.1 ks, obtained between T0+50.8 ks and T0+57.9 ks. An uncatalogued X-ray source is detected within the estimated 3-sigma SVOM/ECLAIRs error region (459 arcsec) and is believed to be the afterglow, given its positional coincidence with the SVOM/VT optical transient (GCN 38516). Using 1725 s of PC mode data and 1 UVOT image, we find an enhanced XRT position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 194.63185, +76.17637 which is equivalent to: RA (J2000): 12h 58m 31.64s Dec(J2000): +76d 10' 34.9" with an uncertainty of 4.5 arcsec (radius, 90% confidence). This position is 5.7 arcmin from the SVOM/ECLAIRs position. We cannot determine at the present time whether the source is fading. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00021739. The results of the full analysis of the XRT observations are available at https://www.swift.ac.uk/ToO_GRBs/00021739. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/38525. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36523] GRB 241209C: Fermi GBM Observation
by GCN Circulars 10 Dec '24

10 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38524 SUBJECT: GRB 241209C: Fermi GBM Observation DATE: 24/12/10 14:15:29 GMT FROM: Christian Malacaria at INAF-OAR <cmalacaria.astro(a)gmail.com> C. Malacaria (INAF-OAR) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 07:22:54.60 UT on 09 December 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 241209C (trigger 755421779/241209308), which was also detected by AstroSat (J. Joshi et al. 2024, GCN 38490) and Swift/BAT-GUANO (J. DeLaunay et al. 2024, GCN 38501). The GBM Final Real-time Localization is reported in GCN 38482. The angle from the Fermi LAT boresight is 36 degrees. The GBM light curve consists of a single emission episode with a duration (T90) of about 11 s (50-300 keV). The time-averaged spectrum from T0-4.1 to T0+9.2 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.4 +/- 0.1 and the cutoff energy, parameterized as Epeak, is 270 +/- 20 keV. The event fluence (10-1000 keV) in this time interval is (4 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+4.8 s in the 10-1000 keV band is 3.3 +/- 0.2 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/" View this GCN Circular online at https://gcn.nasa.gov/circulars/38524. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36522] GRB 241209A: Swift-XRT refined Analysis
by GCN Circulars 10 Dec '24

10 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38523 SUBJECT: GRB 241209A: Swift-XRT refined Analysis DATE: 24/12/10 13:03:21 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: We have analysed 4.9 ks of XRT data for GRB 241209A, from 91 s to 40.8 ks after the BAT trigger. The data comprise 42 s in Windowed Timing (WT) mode (the first 9 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The light curve can be modelled with an initial power-law decay with an index of alpha=1.16 (+0.17, -0.16), followed by a break at T+485 s to an alpha of 8.0 (+0.0, -1.2). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.8 (+/-0.3). The best-fitting absorption column is 3.0 (+1.7, -1.4) x 10^21 cm^-2, in excess of the Galactic value of 2.1 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.7 x 10^-11 (5.0 x 10^-11) erg cm^-2 count^-1. A summary of the WT-mode spectrum is thus: Total column: 3.0 (+1.7, -1.4) x 10^21 cm^-2 Galactic foreground: 2.1 x 10^20 cm^-2 Excess significance: 3.4 sigma Photon index: 1.8 (+/-0.3) If the light curve continues to decay with a power-law decay index of 8.0, the count rate at T+24 hours will be 1.3 x 10^-18 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.0 x 10^-29 (6.8 x 10^-29) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01273071. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/38523. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36521] Fermi Gamma-ray Burst Monitor trigger 755485387 / 241210044 is not a GRB
by GCN Circulars 10 Dec '24

10 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38522 SUBJECT: Fermi Gamma-ray Burst Monitor trigger 755485387 / 241210044 is not a GRB DATE: 24/12/10 12:55:43 GMT FROM: Jacob Smith at Fermi-GBM Team <jrs0118(a)uah.edu> J. Smith (UAH) reports on behalf of the Fermi Gamma-ray Burst Monitor Team: The Fermi Gamma-ray Burst Monitor (GBM) trigger 755485387 / 241210044 at 01:03:02.44 UT on 10 December 2024, tentatively classified as a GRB, is in fact not due to a GRB. This trigger is likely due to recent SFL (C1.9) activity. View this GCN Circular online at https://gcn.nasa.gov/circulars/38522. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36520] LIGO/Virgo/KAGRA S241210fu: Identification of a GW compact binary merger candidate
by GCN Circulars 10 Dec '24

10 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38521 SUBJECT: LIGO/Virgo/KAGRA S241210fu: Identification of a GW compact binary merger candidate DATE: 24/12/10 12:52:37 GMT FROM: Matthieu Gosselin at European Gravitational Observatory <gosselin(a)ego-gw.it> The LIGO Scientific Collaboration, the Virgo Collaboration, and the KAGRA Collaboration report: We identified the compact binary merger candidate S241210fu during real-time processing of data from LIGO Hanford Observatory (H1) and LIGO Livingston Observatory (L1) at 2024-12-10 12:09:00.632 UTC (GPS time: 1417867758.632). The candidate was found by the cWB BBH [1], GstLAL [2], MBTA [3], and PyCBC Live [4] analysis pipelines. S241210fu is an event of interest because its false alarm rate, as estimated by the online analysis, is 2.7e-08 Hz, or about one in 1 year, 1 month. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S241210fu After parameter estimation by RapidPE-RIFT [5], the classification of the GW signal, in order of descending probability, is BBH (98%), Terrestrial (2%), NSBH (<1%), or BNS (<1%). Assuming the candidate is astrophysical in origin, the probability that the lighter compact object is consistent with a neutron star mass (HasNS) is <1%. [6] Using the masses and spins inferred from the signal, the probability of matter outside the final compact object (HasRemnant) is <1%. [6] Both HasNS and HasRemnant consider the support of several neutron star equations of state for maximum neutron star mass. The probability that either of the binary components lies between 3 and 5 solar masses (HasMassGap) is <1%. Two sky maps are available at this time and can be retrieved from the GraceDB event page: * bayestar.multiorder.fits,1, an initial localization generated by BAYESTAR [7], distributed via GCN notice about 30 seconds after the candidate event time. * bayestar.multiorder.fits,2, an initial localization generated by BAYESTAR [7], distributed via GCN notice about 5 minutes after the candidate event time. The preferred sky map at this time is bayestar.multiorder.fits,2. For the bayestar.multiorder.fits,2 sky map, the 90% credible region is 3101 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 4856 +/- 1595 Mpc (a posteriori mean +/- standard deviation). For further information about analysis methodology and the contents of this alert, refer to the LIGO/Virgo/KAGRA Public Alerts User Guide https://emfollow.docs.ligo.org/. [1] T. Mishra et al. PRD 105, 083018 (2022) doi:10.1103/PhysRevD.105.083018 [2] Tsukada et al. PRD 108, 043004 (2023) doi:10.1103/PhysRevD.108.043004 and Ewing et al. (2023) arXiv:2305.05625 [3] Aubin et al. CQG 38, 095004 (2021) doi:10.1088/1361-6382/abe913 [4] Dal Canton et al. ApJ 923, 254 (2021) doi:10.3847/1538-4357/ac2f9a [5] Rose et al. (2022) arXiv:2201.05263 and Pankow et al. PRD 92, 023002 (2015) doi:10.1103/PhysRevD.92.023002 [6] Chatterjee et al. ApJ 896, 54 (2020) doi:10.3847/1538-4357/ab8dbe [7] Singer & Price PRD 93, 024013 (2016) doi:10.1103/PhysRevD.93.024013 View this GCN Circular online at https://gcn.nasa.gov/circulars/38521. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36519] EP241208a: Optical upper limit with Kinder observations
by GCN Circulars 10 Dec '24

10 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38520 SUBJECT: EP241208a: Optical upper limit with Kinder observations DATE: 24/12/10 10:31:06 GMT FROM: Janet Chen at National Central University <janetstars(a)gmail.com> Z. N. Wang, S. Yang (both HNAS), A. Aryan, T.-W. Chen (both NCU), A. K. H. Kong (NTHU), J. Gillanders (Oxford), S. J. Smartt (Oxford/QUB), A. Sankar.K, Y.-H. Lee, H.-Y. Miao, Y. J. Yang, M.-H. Lee, W.-J. Hou, C.-C. Ngeow, Y.-C. Pan, C.-H. Lai, H.-C. Lin, H.-Y. Hsiao, C.-S. Lin, J.-K. Guo (all NCU), L. L. Fan, G. H. Sun (both HNAS), H.-W. Lin (UMich), H. F. Stevance, S. Srivastav, L. Rhodes (all Oxford), M. Nicholl, M. Fulton, T. Moore, K. W. Smith, C. Angus, A. Aamer (all QUB), A. Schultz and M. Huber (both IfA, Hawaii) report: We observed the field of the fast X-ray transient EP241208a (Wang et al., GCN 38477, GCN 38513) using the 40cm SLT at the Lulin Observatory in Taiwan as part of the Kinder collaboration (Chen & Yang et al., 2024 arXiv:2406.09270). The first SLT epoch of observations started at 16:13 UTC on 9th November 2024 (MJD 60653.676), 23.62 hrs after the EP-WXT trigger. We utilize the astroalign (Beroiz et al., 2020, A&C, 32, 100384) and astropy (Astropy Collaboration et al., 2022, ApJ, 935, 167) packages to align and stack the individual frames. The plausible host galaxy J083120.19+490500.1, as quoted in Wang et al. (GCN 38513), is clearly seen in our images. Moreover, we used the Kinder pipeline (Yang et al. A&A 646, A22) to subtract the stacked image from the SDSS DR18 (Almeida et al., 2023) template image. We do not find any new source in the difference images within the 10 arcseconds error circle of EP-FXT. Finally, we utilized the Python-based package AutoPhOT (Brennan & Fraser, 2022, A&A, 667, A62) to perform aperture photometry on our stacked frames. The details of the observations and measured 3-sigma upper limit (in the AB system) are as follows: --------------------------------------------------------------------------------------------------- Telescope | Filter | MJD (start) | t-t0 (hr) | Exposure (s) | Magnitude | avg. Seeing | med. Airmass SLT | r | 60653.676 | 23.62| 300 * 24 | > 20.9 | 1".88 | 1.21 The presented magnitude was calibrated using the field stars from the Pan-STARRS1 catalog and was not corrected for the expected Galactic foreground extinction corresponding to a reddening of A_r = 0.09 mag in the direction of the transient (Schlafly & Finkbeiner 2011). View this GCN Circular online at https://gcn.nasa.gov/circulars/38520. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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