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"- Konus-Wind observation of GRB 110205A (correction to GCN 11659)
- GRB 110205A: detection of optical linear polarization from CAHA
- GRB 110207A: Suzaku WAM observation of the prompt emission
- GRB 110210A: optical upper limit
- GRB 110210A: Swift-XRT refined Analysis
- GRB 110205A: Swift/BAT and Suzaku/WAM joint spectral analysis
- GRB 110210A: Swift-BAT refined analysis
- Swift-BAT refined analysis of outburst from 1E 1841-04.5
- GRB 110210A: Enhanced Swift-XRT position
- GRB 110201A: optical observations
- GRB 110210A: Swift detection of a burst
- GRB 110206A: Swift-XRT confirmation of the X-ray afterglow
- GRB 110208A: Magellan confirmation of the optical afterglow
- Fermi GBM detection of a burst from 1E 1841-045
- Swift/UVOT observations of GRB110208a
- GRB 110205A: Suzaku WAM observation of the prompt emission
- GRB 110208A: Potential afterglow from Magellan
- GRB 110207A: Swift-XRT observations
- GRB 110208A: Swift-XRT refined Analysis
- GRB 110208A: Enhanced Swift-XRT position
- GRB 110208A: Swift-BAT refined analysis
- GRB 110208A: Magellan optical observations
- GRB 110206A: SMARTS optical/IR afterglow decay
- GRB 110208A: Swift detection of a burst
- SGR-like outburst from the magnetar 1E 1841-04.5
- GRB 110205A: optical observations in Mondy observatory
- GRB 110207A: Fermi GBM observation
- GRB 110205A : HCT optical observations
- GRB 110206A: Decay of afterglow candidate
- GRB 110206A: SMARTS optical/IR afterglow candidate observations
- GRB 110207A: TAROT Calern observatory optical observations
- GRB 110205A - Continued PAIRITEL NIR Observations
- GRB 110206A: GROND detection of afterglow candidate
- GRB 110207A: Swift-BAT refined analysis
- GRB 110205A: WSRT radio observation
- GRB 110206A: UVOT detection of afterglow candidate
- GRB110205A: CARMA 3mm Observations
- GRB 110207A: MASTER prompt and early optical observations
- Konus-Wind observation of GRB 110205A
- GRB 110207A: Swift detection of a burst
- GRB 110206A: Swift detection of a probable X-ray afterglow
- GRB 110206A: TAROT La Silla observatory optical observations
- GRB 110205A: Lightbuckets Optical Observations
- GRB 110206A: a long GRB detected by INTEGRAL
- GRB 110205A : Lulin optical observation
- GRB110205A: MITSuME Ishigakijima Optical Observation
- GRB110205A: MITSuME Okayama Optical Observation
- GRB110205A: SMA 1.3mm Observations
- GRB 110205A: Swift/UVOT Continuing Observations
- GRB 110205A: Lulin optical observations and temporal decay index
- Observations GRB 110205A
- GRB 110205A: Swift-BAT refined analysis
- GRB 110205A: Newcastle Observatory Optical Observations
- GRB 110205A: Swift-XRT refined Analysis
- GRB 110205A: LOAO B/R Observation
- GRB 101225A is likely at z~0
- GRB 110205A: optical flare confirmation
- GRB 110205A: NOT redshift confirmation
- GRB 110205A: Enhanced Swift-XRT position
- GRB 110205A: FAST Redshift
- GRB 110205A: GRAS005 optical observations
- GRB 110205A: PAIRITEL NIR Afterglow Detection
- GRB 110205A: Possible Lick/Kast redshift
- GRB 110205A: Swift/UVOT Confirmation of Flaring Afterglow
- GRB 110205A: Liverpool Telescope Afterglow Confirmation
- GRB 110205A: TAROT Calern observatory detection of an optical flare
- GRB 110205A: ROTSE-III, Optical Counterpart is flaring to ~14 mag
- GRB 110205A: TAROT Calern observatory optical detection
- GRB 110205A: Swift detection of a burst with an optical candidate
- GRB 110128A: Fermi GBM detection
- GRB 110201A: Swift-XRT refined Analysis
- GRB110201A: MITSuME Okayama optical upper limits
- Swift/UVOT observations of GRB110201A
- GRB 110201A: Swift-BAT refined analysis
- GRB 110201A: MASTER optical observations
- GRB 110201A: Swift detection of a burst
- GRB110112B: EVLA Observations
- GRB101224A: EVLA Observations
- GRB110112A: EVLA Observations
- GRB110128A: MITSuME Okayama optical upper limits
- GRB 110125A: Fermi GBM detection
- GRB 101112A: Maidanak and CrAO optical observations
- GRB110128A: TNG NIR observations
- GRB 110128A, Swift-BAT refined analysis
- GRB 110128A: TAROT-Calern refined analysis
- GRB 110128A: Swift/UVOT observations
- GRB 110128A: Swift-XRT refined Analysis
- GRB 110120A: Suzaku WAM observation of the prompt emission
- GRB 110128A: WHT redshifts of nearby field galaxies
- GRB 110128A: VLT/X-shooter redshift
- GRB 110128A: Enhanced Swift-XRT position
- GRB 110128A: Afterglow detection from NOT
- GRB 110128A: TAROT Calern observatory upper limits
- GRB 110128A: Swift detection of a burst
- IBAS Alerts n. 6130 and 6131 are not due to a GRB
- Konus-Wind observation of GRB 110120A
- GRB 110123A: Fermi GBM detection
- GRB 110106B, radio observations
- GRB 110120A: MASTER optical observations
- GRB 110120A: Fermi LAT detection