GCN Circulars
GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"3043 results found.
- LIGO/Virgo S190510g: Las Cumbres Observatory Galaxy Targeted Counterpart Search
- LIGO/Virgo S190510g: GRAWITA REM and Loiano optical observations
- LIGO/Virgo S190510g: GRAWITA VST-ESO PARANAL optical observations
- LIGO/Virgo S190510g: Xinglong/Schmidt Follow-Up Observations
- LIGO/Virgo S190510g: Lick/KAIT Follow-Up Observations
- LIGO/Virgo S190510g: Lulin Optical Follow-up Observations
- LIGO/Virgo S190510g: GRAWITA REM optical observations
- Fermi GRB190507.97 Global MASTER-Net observations report
- Fermi GRB190507.27 Global MASTER-Net observations report
- IceCube-190504A: MASTER optical monitoring analysis
- Fermi GRB190506.58 Global MASTER-Net observations report
- Fermi GRB190505.05 Global MASTER-Net observations report
- Fermi GRB190504.68 Global MASTER-Net observations report
- LIGO/Virgo S190503bf Global MASTER-Net observations report
- IceCube-190503A: Lick/KAIT Follow-Up Observations
- IPN Triangulation of GRB 190501A (long/bright)
- LIGO/Virgo S190426c: YAHPT Optical Observation
- LIGO/Virgo S190426c: MASTER analysys of GRAWITA transients
- LIGO/Virgo S190426c: GRAWITA transients from Asiago Schmidt wide field observations
- LIGO/Virgo S190426c: OAJ-GRANDMA observation report
- LIGO/Virgo S190425z: MASTER explanation of the nature of an optical flash detected by a Swift as a short flare on a fast-moving WISE brown
- LIGO/Virgo S190425z: SVOM/GWAC-F60A observations
- LIGO/Virgo S190426c: COATLI Optical Observations of Galaxies
- LIGO/Virgo S190426c: Lick/KAIT Follow-Up Observations
- LIGO/Virgo S190426c: CNEOST Optical Observations
- LIGO/Virgo S190425z: CNEOST Optical Observations
- LIGO/Virgo S190425z: BOOTES-5/JGT observations of galaxies
- LIGO/Virgo S190425z: Lijiang 2.4-m Telescope Follow-up Observations
- LIGO/Virgo S190425z: Additional Pan-STARRS transients in the skymap
- LIGO/Virgo S190425z: GRANDMA follow-up observations with Les Makes-T60, AZT-8 and Abastumani-T70
- LIGO/Virgo S190425z: Further MMT Follow-Up Observations
- Baksan Neutrino Observatory Alert 190405.62: Global MASTER-Net:LIGO/Virgo S190425z: PanSTARR OT AT2019ebq/PS19qp
- LIGO/Virgo S190425z: COATLI Observations of Galaxies
- LIGO/Virgo S190425z: TAROT-GRANDMA observation report
- LIGO/Virgo S190425z: Las Cumbres Observatory Galaxy Targeted Counterpart Search
- LIGO/Virgo S190425z: KMTNet Observation
- LIGO/Virgo S190425z: Las Cumbres Observatory Galaxy Targeted Counterpart Search
- LIGO/Virgo S190425z: STARE2 simultaneous L-band radio observations
- LIGO/Virgo S190425z: OVRO-LWA simultaneous low frequency radio observations of localization region
- LIGO/Virgo S190425z: Lulin Follow-Up Observations
- LIGO/Virgo S190425z: J-GEM optical follow-up observations with Subaru/FOCAS
- LIGO/Virgo S190425z: Xinglong/Schmidt follow-up observations
- LIGO/Virgo S190425z: SQUEAN Observation
- LIGO/Virgo S190425z: MMT Follow-Up Observations
- LIGO/Virgo S190425z: Lick/KAIT Follow-Up Observations
- LIGO/Virgo S190421ar: Lick/KAIT Follow-Up Observations
- Swift GRB190422.96 Global MASTER-Net observations report
- Fermi GRB190422.67 Global MASTER-Net observations report
- LIGO/Virgo S190421ar Global MASTER-Net observations report
- Konus-Wind observation of GRB 190415A
- Fermi GRB190420.98 Global MASTER-Net observations report
- Fermi GRB190419.41 Global MASTER-Net observations report
- Fermi GRB190417.46 Global MASTER-Net observations report
- LIGO/Virgo S190412m: TAROT-GRANDMA observation report.
- Fermi GRB190415.17 Global MASTER-Net observations report
- LIGO/Virgo S190408an: GRAWITA optical observations of MASTER OT J231043.63+470956.4
- GRB 190404C: MITSuME Akeno and Okayama optical upper limits
- GRB 140404C: MAXI/GSC detection
- GRB 190330A: MITSuME Akeno and Okayama optical upper limits
- Trigger 896552: Swift detection of PSR B1055-52
- Swift Trigger 895479: Detection of GRO J2058+42
- GRB 190326A: Swift-BAT refined analysis - a soft-short GRB or an SGR
- Swift Trigger 895257: Detection of GRO J2058+42 in outburst
- Fermi Trigger 575251142 / GRB 190325999 / GRB 190325A: BALROG localization
- SWIFT GRB190323.85 Global MASTER-Net observations report
- Swift Trigger 894268: Detection of GRO J2058+42 in outburst
- GRB 190220A: Swift-BAT refined analysis
- GRB 190219A: NEXT-0.6m optical upper limit
- GRB190219A: MASTER Global Robotic Net optical observation
- GRB 190211A: Swift detection of a burst
- GRB 190204A: COATLI Optical Detection of the Fading Afterglow
- GRB 190129B: MASTER Global Robotic Net optical observation
- GRB 190122B: AstroSat CZTI detection
- Trigger 884906: Swift detection of MAXI J1631-479
- Konus-Wind observation of GRB 190114C
- GRB 190114C: LSGT optical observation
- GRB 190114C:Insight-HXMT/HE detection
- GRB 190114C: SPI-ACS/INTEGRAL extended emission detection
- GRB 190114C: AGILE/MCAL detection
- GRB190109B: MITSuME Akeno optical upper limits
- GRB 190114C: Fermi-LAT detection
- GRB 190114C: Fermi GBM detection
- MAGIC detects the GRB 190114C in the TeV energy domain
- GRB 190114B: Mondy optical afterglow detection
- GRB 190114C: MASTER 4-polarizations filters OT detection
- GRB 190114C: MASTER afterglow Detection
- GRB 190114C: Swift detection of a very bright burst with a bright optical counterpart
- GRB 190106A: GMG continued observation
- GRB 190109B: COATLI Optical Observations
- GRB 190109A: Swift-BAT refined analysis
- GRB 190109B: Swift-XRT observations
- GRB 190109B: Swift detection of a burst
- GRB 190106A : continued TSHAO optical observations
- GRB 190106A: NEXT-0.6m and Xinglong-2.16m photometric single powerlaw decay
- GRB 190106A: Swift-BAT refined analysis
- IceCube-190104A: MASTER optical observation
- GRB 190103B: Swift-BAT refined analysis
- Swift Trigger 880127 is not a GRB
- GRB 181222B: Global MASTER Net observations of the short bright Fermi GRB error box.
- GRB 181213A: Mondy optical observations