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 200608A: Swift detection of a burst
- GRB 200607B: AstroSat CZTI detection
- GRB 200522A: Further HST F125W Observations
- Fermi GRB 200607B: Global MASTER-Net observations report
- GRB 200607B: Fermi GBM Final Real-time Localization
- Fermi GRB 200607A: Global MASTER-Net observations report
- IPN triangulation of GRB 200605A (short)
- GRB 200607A: Fermi GBM Final Localization
- GRB 200607A: BALROG localization (Fermi Trigger 613212114 / GRB 200607362)
- GRB 200530A: Fermi GBM detection
- GRB 200530A: CALET Gamma-Ray Burst Monitor detection
- Correction to the GCN 27886: Previous bursts of 1RXS J1708-4009 (Swift trigger 975998)
- 1RXS J1708−4009: Swift-BAT refined analysis
- Fermi GRB 200605A: Global MASTER-Net observations report
- GRB 200605A: Fermi GBM Final Real-time Localization
- GRB 200530A: Fermi-LAT detection
- GRB 200604A: AstroSat CZTI detection
- Fermi trigger No 612988790: Global MASTER-Net observations report
- Fermi GRB 200604A: Global MASTER-Net observations report
- GRB 200604A: Fermi GBM Final Real-time Localization
- Swift detection of an SGR-like burst from 1RXS J1708−4009
- Baksan Neutrino Observatory Alert 200603.12: Global MASTER-Net observations report
- GRB 200529A: Swift/UVOT Upper Limits
- Konus-Wind observation of GRB200528A
- GRB 200601A: Insight-HXMT/HE detection
- IceCube-200530A: Upper limits from a search for additional neutrino events in IceCube
- Baksan Neutrino Observatory Alert 200601.42: Global MASTER-Net observations report
- Fermi-LAT Gamma-ray Observations of IceCube-200530A
- GRB 200529A: MITSuME Akeno optical upper limits
- Fermi GRB 200601A: Global MASTER-Net observations report
- GRB 200601A: Fermi GBM Final Real-time Localization
- IceCube-200530A: not observable by Fermi-GBM
- Fermi GRB 200531A: Global MASTER-Net observations report
- IceCube-200530A: No significant detection in HAWC
- IceCube-200530A: Candidate Counterparts from the Zwicky Transient Facility
- IceCube-200530A: No ANTARES neutrino counterpart
- GRB 200531A: Fermi GBM Final Real-time Localization
- IceCube Alert 200530.33: Global MASTER-Net observations report
- GRB 200529A: Swift-BAT refined analysis
- Konus-Wind observation of GRB 200524A
- IceCube-200530A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- IceCube-200530A - IceCube observation of a high-energy neutrino candidate event
- GRB 200530A: AstroSat CZTI detection
- GRB 200529A: Swift-XRT refined Analysis
- Fermi GRB 200530A: Global MASTER-Net observations report
- GRB 200530A: Fermi GBM Final Real-time Localization
- GRB 200528A: CAHA Upper Limit
- GRB 200529A: Fermi GBM Detection
- GRB 200529A: LCO Optical Afterglow Detection
- Fermi GRB 200529B: Global MASTER-Net observations report
- Fermi trigger No 612429771: Global MASTER-Net observations report
- GRB 200528A: CALET Gamma-Ray Burst Monitor detection
- GRB 200529B: Fermi GBM Final Real-time Localization
- GRB 200529A: BOOTES-2/TELMA early optical upper limit
- GRB 200528A: Swift-XRT refined Analysis
- GRB 200524A: SAO RAS optical observations
- GRB 200524A: Assy continued optical observations
- GRB 200528A: Assy optical upper limit
- GRB 200529A: Enhanced Swift-XRT position
- GRB 200529A: KAIT Optical Afterglow Confirmation
- GRB 200529A: NOT optical afterglow
- GRB 200529A: Swift detection of a burst
- GRB 200529A: Fermi GBM Final Real-time Localization
- Swift GRB200529.04: Global MASTER-Net observations report
- GRB 200528A: NOT optical upper limits
- GRB 200528A: Fermi GBM Observation
- GRB 200528A: Swift/UVOT Upper Limits
- GRB 200528A: Swift-BAT refined analysis
- GRB 200528A: 1.3m DFOT Optical Upper Limits
- GRB 200528A: Nanshan/NEXT optical upper limit
- GRB 200528A: Enhanced Swift-XRT position
- Swift GRB 200528A: Global MASTER-Net observations report
- GRB 200528A: MITSuME Akeno optical upper limits
- GRB 200528A: Potential host galaxy in PanSTARRS, SDSS and WISE
- GRB 200528A: Swift detection of a burst
- GRB 200528A: Fermi GBM Final Real-time Localization
- GRB 200524A: Assy optical observations
- Baksan Neutrino Observatory Alert 200526.85: Global MASTER-Net observations report
- IceCube-200523A: Upper limits from a search for additional neutrino events in IceCube
- GRB 200522A: HST F125W new point source detection
- GRB 200522A: Hubble Space Telescope Near-IR F160W Observations
- GRB200524A: UVOT detection
- GRB 200524A: optical upper limits from further MITSuME Akeno observation
- Fermi GRB 200525A: Global MASTER-Net observations report
- GRB 200522A: Gemini North optical imaging
- GRB 200524A: CrAO optical observations
- GRB 200524A: Kitab observatory afterglow observations
- GRB 200525A: Fermi GBM Final Real-time Localization
- GRB 200524A: AstroSat CZTI detection
- GRB 200524A: Further Liverpool Telescope observations
- Fermi-LAT Gamma-ray Observations of IceCube-190523A
- GRB200521A: ASIM observation
- GRB 200524A: KAIT Optical Observations
- GRB 200524A: MITSuME Akeno optical observation
- GRB 171205A: ATCA observations of late-time radio emission
- GRB 200524A: Swift-XRT afterglow detection
- GRB 200524A: OAJ multicolor afterglow detection
- GRB 200524A: Fermi GBM detection
- GRB 200524: Swift/UVOT observations missed the ZTF20abbiixp position
- GRB 200524A: CAHA multicolor afterglow detection