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.
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 170804A: Swift detection of a burst with optical counterpart
- Swift Trigger 766161 is not a GRB
- GRB 170803A: Swift-XRT refined Analysis
- GRB 170803A: Enhanced Swift-XRT position
- GRB 170803A: Fermi GBM observation
- GRB 170803A: Swift detection of a burst with an optical counterpart
- GRB 170802A: Fermi GBM detection
- Swift Trigger 765783 is not an astrophysical event.
- GRB 160814A: Lomonosov BDRG gamma ray discovery
- GRB 170728B: time correction to MASTER GCN Circular 21391
- Swift J181723.1-164300: Swift detection of another pulse of the new Galactic source
- GRB 170728B: Swift/UVOT Further Analysis
- Konus-Wind observation of GRB 170728B
- GRB 170726A: AstroSat CZTI detection
- GRB 170714A: Chandra observations
- GRB 170728B: VLA radio afterglow detection
- GRB 170728B: Optical observations at Crni Vrh
- GRB 170728B: BOOTES-2/TELMA optical detection during the extended gamma-ray phase
- GRB170730A detecetd by INTEGRAL. Refined analysis
- GRB 170728B: MASTER-IAC first minute short GRB early OT detection
- IBAS weak Alert nr.7881: possible GRB 170730A
- GRB 170728B: COATLI Observations And Confirmation of Fading
- GRB 170728B: Swift/UVOT Upper Limits
- GRB 170728B iTelescope observation
- GRB 170728A: Swift/UVOT Detection
- Swift J181723.1-164300: Swift-BAT refined analysis
- GRB 170728B, Swift-BAT refined analysis
- GRB 170728B: Fermi GBM detection
- GRB 170728A: LCO observations
- GRB 170728B: I-band detection from 1.5m OSN
- GRB 170728B: Fermi-LAT detection
- GRB170714A: XMM observation of the afterglow
- GRB 170728A: Swift-XRT refined Analysis
- GRB 170728B: Enhanced Swift-XRT position
- GRB 170728B: Swift-XRT refined Analysis
- GRB 170728B: LT afterglow confirmation
- GRB 170728B: NOT optical afterglow confirmation
- GRB 170728B: position of the TNG optical counterpart
- GRB 170728B: TNG optical afterglow candidate
- GRB 170728B: Swift detection of a short burst
- GRB 170728A: Swift-BAT refined analysis
- Swift triggers on a new galactic source: Swift J181723.1-164300
- GRB 170728A: Enhanced Swift-XRT position
- GRB 170728A: Swift detection of a burst
- GRB 170726A: Insight-HXMT detection
- GRB 170724A, Swift-BAT refined analysis
- GRB 170724A: Swift detection of a burst
- Fermi GBM trigger 522477026/170723188 is not a GRB
- Fermi GBM trigger 522470841/170723116 is not a GRB
- Fermi GBM trigger 522334209/170721535 is not a GRB
- GRB170714A: ATCA observation
- GRB 170714A: Bastille Day Burst redshift from OSIRIS/GTC
- Trigger 763539 from Swift is probably not astrophysical
- Fermi GBM trigger 522048561/170718229 is not a GRB
- GRB 170714A: NOEMA non-detection of the Bastille Day Burst
- LIGO/Virgo G275697: LOFAR follow-up
- GRB 170710B: Further Swift-XRT observations
- Correction to GCN Circular 21351: GRB 170714A: Swift/UVOT Observations
- GRB170714A: VLA Observations of the Bastille Day Ultra-long Burst
- GRB 170714A: Swift/UVOT Observations
- GRB 170714A: TNG NIR observations
- Fermi GBM trigger 521905898/170716577 is not a GRB
- GRB 170702A: AstroSat CZTI detection
- GRB 170714A, Swift-BAT refined analysis
- GRB 170714A: z-band afterglow candidate for OSIRIS/GTC
- GRB 170714A: Bastille Day Burst: ULGRB or RTDE?
- GRB 170714B: Insight-HXMT detection
- GRB 170714A: Swift-XRT refined Analysis
- Fermi GBM Detection of possible burst from AXP 4U 0142+61
- GRB 170714A: Enhanced Swift-XRT position
- GRB 170714A: Swift detection of a burst
- GRB 170712A: AstroSat CZTI detection
- Correction to GCN Circular 21337: GRB 170710D CALET Gamma-Ray Burst Monitor detection
- GRB 170710D CALET Gamma-Ray Burst Monitor detection
- GRB 170708B CALET Gamma-Ray Burst Monitor detection
- GRB 170703A CALET Gamma-Ray Burst Monitor detection
- GRB 170702A CALET Gamma-Ray Burst Monitor detection
- GRB 170711A: ISON/Terskol and AbAO optical observations
- GRB 170712A: Insight-HXMT detection
- GRB 170711A: Swift-BAT refined analysis
- Konus-Wind observation of GRB 170708A
- GRB 170711A: Swift/UVOT Upper Limits
- GRB 170711A: RATIR Optical and NIR Observations
- GRB 170705A: AstroSat CZTI detection
- GRB 170710C: a long GRB detected by INTEGRAL
- GRB 170711A: Swift-XRT refined Analysis
- GRB 170711A: Fermi GBM observation
- GRB 170711A: Enhanced Swift-XRT position
- GRB 170711A: Prompt enhanced Swift-XRT position
- GRB 170711A: Swift detection of a burst
- GRB 170705A: TShAO optical observations
- GRB 170710B: Fermi GBM observation
- GRB 170710B: Swift-XRT and UVOT observations
- GRB 170710B: Swift ToO observations
- GRB 170710B: Swift detection of a burst
- GRB170710A: Swift/UVOT detection
- IPN Triangulation of GRB 170708A (short)
- GRB 170710A: Swift-BAT refined analysis
- GRB 170710A: Swift-XRT refined Analysis
- GRB 170710A: Gemini-S candidate counterpart