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.
Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
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"- GRB 240118C: GECAM-B detection of a long burst
- GRB 240119A: AstroSat CZTI detection of a short burst
- GRB 240118A: Mondy optical observations
- GRB 240118A: Swift-XRT afterglow detection
- GRB 240118C: Fermi GBM Observation
- Fermi GRB 240119A: Global MASTER-Net observations report
- IceCube-240105A: Detection of NIR flare of PKS 0446+11 with WINTER
- GRB 240119A: Fermi GBM Final Localization
- GRB 240117A: CALET Gamma-Ray Burst Monitor detection
- GRB 240118C: Swift/BAT-GUANO detection of a burst
- GRB 240118A: GRBAlpha detection
- AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-240118A: correction on the localization
- GRB 240115A: Fermi GBM Observation
- Swift triggers 1209631, 1209632, 1209635 and 1209644 are not interesting astrophysical events
- GRB 240118C: Fermi GBM Final Localization
- GRB 240118D: AstroSat CZTI detection
- GRB 240117A: AstroSat CZTI detection
- GRB 240118A: Swift ToO observations
- GRB 240118A: AbAO optical upper limit
- Fermi GRB 240118B: Global MASTER-Net observations report
- GRB 240118A: NuSTAR Offline Analysis of the GRB
- GRB 240117A: Glowbug gamma-ray detection
- GRB 240118A: Swift/BAT-GUANO detection of a burst outside the coded FOV
- Konus-Wind detection of GRB 240118A
- AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEm-240118A
- GRB 240118C: BALROG localization (Fermi Trigger 727291408 / GRB 240118725)
- GRB 240118A: NuSTAR Detection of a Long GRB
- GRB 240118A: Fermi GBM Observation
- GRB 240118B: Fermi GBM Final Real-time Localization
- LAT GRB240118.08: Global MASTER-Net observations report
- GRB 240118A: Fermi-LAT detection
- GRID detection of GRB 231230A
- GRB 240118A: Fermi GBM Final Real-time Localization
- GRB 240115A: Swift/BAT-GUANO detection of a short burst
- Swift Trigger 1209406 is not an astrophysical event
- Swift Triggers 1209401 and 1209403 are not astrophysical events
- IPN triangulation of GRB 240112A (long)
- Swift Triggers 1209371 through 1209374 are not astrophysical events
- Swift Triggers 1209369 and 1209370 are not astrophysical events
- GRB 240115B: AstroSat CZTI detection
- LIGO/Virgo/KAGRA S240109a: Upper limits from Swift/BAT-GUANO
- GRB 240115B: Fermi GBM Detection
- IceCube-240105A: ZTF optical observation of blazar PKS 0446+11
- GRB 240112D: Glowbug gamma-ray detection
- GRB 240112C: Glowbug gamma-ray detection
- GRB 240112C: VZLUSAT-2 detection
- GRB 240107A: VZLUSAT-2 detection
- Integral GRB240115.70: Global MASTER-Net observations report
- Fermi GRB 240115B: Global MASTER-Net observations report
- GRB 240115B: A long GRB detected by INTEGRAL
- GRB 240115B: Fermi GBM Final Real-time Localization
- Konus-Wind detection of GRB 240112C
- Fermi GRB 240115A: Global MASTER-Net observations report
- GRB 240115A: Fermi GBM Final Real-time Localization
- GRB 240112C: GRBAlpha detection
- GRB 240114A: MAXI/GSC detection
- GRB 240112C: Swift/UVOT Detection
- GRB 240112C: Fermi GBM Detection
- Fermi trigger No 726773850: Global MASTER-Net observations report
- GRB 240112C: Swift-XRT refined Analysis
- GRB 240112C: SAO RAS optical observations
- GRB 240112E: Fermi GBM Final Localization
- Fermi GRB 240112D: Global MASTER-Net observations report
- GRB 240112D: Fermi GBM Final Real-time Localization
- Fermi trigger No 726774492: Global MASTER-Net observations report
- Swift GRB 240112C: Global MASTER-Net observations report
- Fermi GRB 240112B: Global MASTER-Net observations report
- GRB 240109A: Swift-BAT refined analysis
- GRB 240112C: Swift detection of a burst with an optical counterpart
- GRB 240112B: Fermi GBM Final Real-time Localization
- GRB 240112A: GECAM detection of a burst
- GRB 240109A: Fermi GBM Observation
- GRB 240110A: AstroSat CZTI detection
- Fermi-LAT detection of increased gamma-ray activity of blazar PKS 0446+11, located inside the IceCube-240105A error region
- GRB 240108A: Glowbug gamma-ray detection
- GRB 231214A: ATCA Radio Upper Limits
- GRB 240106B: Glowbug gamma-ray detection
- GRB 240106A: Glowbug gamma-ray detection
- IceCube-240105A: Upper limits from a search for additional neutrino events in IceCube
- GRB 240109B: Fermi GBM Final Real-time Localization
- IceCube-240105A: Three candidates from the Zwicky Transient Facility
- LIGO/Virgo/KAGRA S240109a: Updated Sky localization
- Konus-Wind detection of GRB 240101C
- GRB 231215A: radio detection with the VLA
- GRB 230818A: further radio observations with the VLA
- GRB 230812B: further radio observations with the VLA
- Swift GRB240109.17: Global MASTER-Net observations report
- GRB 240107A: AstroSat CZTI detection
- LIGO/Virgo/KAGRA S240109a: Identification of a GW compact binary merger candidate
- GRB 240109A: Swift detection of a short burst
- LIGO/Virgo/KAGRA S240104bl: Upper limits from Swift/BAT-GUANO
- IceCube-240105A: JCMT SCUBA2 Detection of Two Bright Submillimeter Sources
- Update of IceCube-240105A - Corrected errors
- GRB 240106A: GRBAlpha detection
- LIGO/Virgo/KAGRA S240107b: Updated Sky localization and Source Classification
- GRB 240107A: MAXI/GSC detection
- Fermi trigger No 726347794: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S240107b: Identification of a GW compact binary merger candidate
- GRB 240106B: Fermi GBM Final Real-time Localization
- Fermi trigger No 726194053: Global MASTER-Net observations report