GCN Circulars
GCN Circulars are rapid bulletins submitted by and distributed to the community. See the documentation for help with subscribing to or submitting Circulars.
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search
To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.
Advanced Search Examples (click to copy):
subject:"Swift"body:"GRB"submitter:"Judith Racusin"11848 results found.
- GRB 200101A: BALROG localization (Fermi Trigger 599603971 / GRB 200101861)
- GRB 200101A: Fermi GBM Final Real-time Localization
- IceCube-191231A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
- GRB 191221B: CALET Gamma-Ray Burst Monitor detection
- Konus-Wind observation of GRB 191227A
- Konus-Wind observation of GRB 191227B
- IPN triangulation of GRB 191227B (short)
- GRB 191228A: Swift-XRT refined Analysis
- LIGO/Virgo S191216ap: Two candidate counterparts from UKIRT/WFCAM z-band observations
- GRB 191228A: Swift detection of a burst
- Swift GRB191228.00: Global MASTER-Net observations report
- GRB 191227A: Marginal detection by Fermi-LAT
- Swift GRB191227.07: Global MASTER-Net observations report
- LIGO/Virgo S191213g: AT2019wxt 10.4m GTC further spectroscopy
- Swift GRB191226.25: Global MASTER-Net observations report
- Swift GRB191226.02: Global MASTER-Net observations report
- Konus-Wind observation of GRB 191221B
- LIGO/Virgo S191222n : No significant candidates in FRAM-TAROT-GRANDMA observations
- GRB 191221B: Swift/UVOT Detection
- LIGO/Virgo S191222n: no counterpart candidate in SVOM/GWAC observations
- GRB 191220.59: AstroSat CZTI detection
- GRB 191221B: AstroSat CZTI detection
- GRB 191221B: Swift-XRT refined Analysis
- LIGO/Virgo S191213g : No significant candidates found in GRANDMA citizen science observations
- LIGO/Virgo S191222n: No counterpart candidates in Fermi-LAT observations
- GRB 191221B: MASTER VWFC OT yearly detection
- GRB 191221B: Correction to GCN26551 - VIRT OT observation
- GRB 191221B: VIRT Optical Upper Limits
- GRB 191221B: AGILE/MCAL observations
- LIGO/Virgo S191222n: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S191222n: No counterpart candidates in HAWC observations
- Baksan Neutrino Observatory Alert 191222.09: Global MASTER-Net observations report
- GRB 191221B: Swift detection of a burst and a very bright optical candidate
- Fermi trigger No 598648473: Global MASTER-Net observations report
- LIGO/Virgo S191216ap: No radio candidates so far in the VLA/JAGWAR galaxy targeted search
- LIGO/Virgo S191216ap: MASTER optical observation
- LIGO/Virgo S191216ap : No significant candidates in FRAM-TAROT-GRANDMA observations
- LIGO/Virgo S191213g: VLA follow-up of AT2019wxt/PS19hg
- GRB 191220A: AbAO optical observations
- Fermi trigger No 598543714: Global MASTER-Net observations report
- LIGO/Virgo S191213g: DCT observation of AT2019wxt
- GRB 191220A: Swift detection of a burst
- Swift GRB191220.56: Global MASTER-Net observations report
- LIGO/Virgo S191220af: Global MASTER-Net observations report
- LIGO/Virgo S191216ap: AstroSat CZTI upper limits
- LIGO/Virgo S191216ap: Subaru/Hyper Suprime-Cam observations of GW+IceCube+HAWC error region
- Konus-Wind observation of GRB 191218A
- LIGO/Virgo S191216ap, Swift XRT observations: 16 X-ray sources in the HAWC error region search
- LIGO/Virgo S191213g: No counterpart candidate in the NOWT observations
- LIGO/Virgo S191216ap: No candidates found in CHES observations of HAWC error region
- Konus-Wind observation of GRB 191213A (ulong)
- LIGO/Virgo S191216ap: GRAWITA Loiano observations of HAWC error region
- LIGO/Virgo S191216ap and IceCube neutrino: Swift XRT sources
- LIGO/Virgo S191215w : No significant candidates in TAROT - FRAM - GRANDMA observations.
- LIGO/Virgo G191216ap: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S191216ap: Coverage and upper limits from MAXI/GSC observations
- Fermi-LAT Gamma-ray Observations of IceCube-191215A
- LIGO/Virgo S191216ap: Global MASTER-Net observations report
- LIGO/Virgo S191216ap: No counterpart candidates in HAWC observations
- LIGO/Virgo S191215w: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S191215w: AstroSat CZTI upper limits
- LIGO/Virgo S191215w: No counterpart candidates in HAWC observations
- LIGO/Virgo S191215w: Coverage and upper limits from MAXI/GSC observations
- IceCube Alert 191215.47: Global MASTER-Net observations report
- LIGO/Virgo S191213g: Lulin Follow-up Observations of ZTF19acykzsk/AT2019wqj
- LIGO/Virgo S191213g: GRAWITA TNG classification of ZTF19acykzsk
- LIGO/Virgo S191213g: AstroSat CZTI upper limits
- LIGO/Virgo S191213g: No counterpart candidates in Fermi-LAT observations
- Fermi trigger No 597909938: Global MASTER-Net observations report
- LIGO/Virgo S191213g: Coverage and upper limits from MAXI/GSC observations
- Baksan Neutrino Observatory Alert 191211.1: Global MASTER-Net observations report
- Possible HAWC-detected GRB 191210A: Fermi-LAT Upper Limits
- Possible HAWC-detected GRB 191210A: Swift-XRT observations
- LIGO/Virgo S191205ah: no counterpart candidate in SVOM/GWAC observations
- GRB 191207A: Possible GRB detected in Fermi-LAT blind search
- LIGO/Virgo S191205ah : No significant candidates in FRAM - TAROT – GRANDMA observations
- LIGO/Virgo S191205ah: MASTER OT 1.5m OSN imaging and 10.4m GTC spectroscopy
- LIGO/Virgo S191204r: GRAWITA VST-ESO PARANAL observations.
- LIGO/Virgo S191205ah: AstroSat CZTI upper limits
- Fermi-LAT Gamma-ray Observations of IceCube-191204A
- LIGO/Virgo S191205ah: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S191129u : No significant candidates in FRAM-TAROT-GRANDMA observations.
- LIGO/Virgo S191204r: No significant candidates in FRAM-TAROT-GRANDMA observations.
- LIGO/Virgo S191204r: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S191205ah: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S191205ah: No counterpart candidates in HAWC observations
- LIGO/Virgo S191205ah: Global MASTER-Net observations report
- LIGO/Virgo S191204r: no counterpart candidates in the Swift/BAT observations
- GRB 191205A: Fermi GBM Final Real-time Localization
- IceCube-191204A: Upper limits from Fermi-GBM Observations
- Konus-Wind observation of GRB191202A
- LIGO/Virgo S191204r: Coverage and upper limits from MAXI/GSC observations
- GRB 191202A: Fermi-LAT detection
- GRB 191202A: Fermi GBM observation
- GRB 191202A: AstroSat CZTI detection
- GRB 191202A: Fermi GBM Final Real-time Localization
- LIGO/Virgo S191129u: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S191129u: No counterpart candidates in HAWC observations
- LIGO/Virgo S191129u: Coverage and upper limits from MAXI/GSC observations
- GRB 191125B: MASTER-VWFC synchronous observation