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"2974 results found.
- GRB 130508A: Refined Swift-XRT analysis: Correction to GCN 14612
- GRB 130508A, Swift-BAT refined analysis
- GRB 130508A: Swift detection of a probable burst
- GRB 130505A: optical observations
- IPN Triangulation of GRB 130504B
- GRB 130504B: Fermi GBM detection
- GRB 130504A, Swift-BAT refined analysis
- GRB 130427A optical time series
- GRB 130427A: MITSuME Okayama Optical Observation
- GRB 130427A: Swift detection of a very bright burst with a likely bright optical counterpart
- GRB 130420B: Swift/UVOT Upper Limits
- GRB 130420B, Swift-BAT refined analysis
- GRB 130420A, Swift-BAT refined analysis
- GRB 130420B: MASTER-Net optical observations
- GRB 130420B: Swift detection of a burst
- GRB130408A: Swift/UVOT followup observations
- GRB 130408A: Swift/UVOT Detection of the Optical Afterglow
- GRB 130408A: Liverpool Telescope Optical candidate detection
- Swift Trigger 552142: a possible GRB
- IPN triangulation of GRB 130228A
- SGR 1806-20 outburst (trigger 549841), Swift-BAT refined analysis
- GRB 130216A: Further Swift-BAT refined analysis
- GRB 130215A: Xinglong optical observations
- GRB 121123A: optical observations
- GRB 130131A: MITSuME Akeno Optical upper limits
- GRB 130131B: MITSuME Akeno Optical upper limits
- GRB 130131B: MITSuME Okayama optical upper limits
- GRB 130131A: Swift detection of a burst
- GRB 130122A: RTT150 optical observations
- GRB 130122A: Swift/UVOT Detection
- GRB 130122A: T100 observations
- GRB 130122A: Swift detection of a burst with an optical counterpart
- Swift-BAT refined analysis of SGR 1E 1841-045 (Trigger=543763)
- GRB 121212A: Swift detection of a burst
- GRB 121202A: Swift detection of a burst
- GRB 121201A: a GRB with an optical counterpart
- GRB 121128A, Swift-BAT refined analysis
- GRB 121123A: Swift-BAT refined analysis
- GRB 121117A: Swift/UVOT Observations
- GRB 121117A: ROTSE-III Optical Limits
- GRB 121102A: Enhanced Swift-XRT position
- GRB 121102A: Swift-XRT refined Analysis
- GRB 121102A: Swift-BAT refined analysis
- GRB 121102A: Swift detection of a burst
- GRB 121027A: sub-mm upper limit
- GRB 121029A: Fermi GBM detection
- GRB 121027A: Swift-XRT refined Analysis
- GRB 121027A: Brightening IR counterpart
- GRB 121024A: Swift detection of a burst with an optical counterpart
- IPN Triangulation of short hard GRB 121011B
- GRB 121011A, Swift-BAT refined analysis
- Swift-BAT refined analysis of the SGR 1806-20 outburst (trigger 535747)
- Trigger 535733: Swift possible detection of SAX J1828.5-1037
- GRB 120927A, Swift-BAT refined analysis
- GRB 120923A: Swift-BAT refined analysis
- GRB 120922A: Swift-BAT refined analysis
- GRB 120919A: Swift-XRT observations
- GRB 120918A: Swift-BAT refined analysis
- GRB 120913A: Swift-BAT refined analysis
- GRB 120913B: Swift detection of a burst
- GRB 120817A: FTN and FTS observations
- GRB 120811C: Swift-BAT refined analysis
- GRB 120811C: MASTER-Amur observations of fading OT
- GRB 120803B: Swift-BAT refined analysis
- GRB 120803B: MITSuME Akeno Optical upper limits
- GRB 120803B: Swift detection of a burst
- GRB 120802A: Swift-BAT refined analysis
- Konus-Wind observation of GRB 120728B
- GRB 120729A: Swift detection of a burst with an optical afterglow
- GRB 120716A: optical observation in Maidanak observatory
- GRB 120724A, Swift-BAT refined analysis
- Fermi GBM trigger 120716.498 is not a GRB
- Swift-BAT refined analysis of 1E 1841-045 (Trigger=526660)
- Trigger 526660: Swift detection of 1 E 1841-045 (aka Kes 73)
- GRB 120712A: GROND Detection of the Optical/NIR Afterglow Candidate and photo-z
- GRB 120707A: Fermi GBM Detection of a Bright Burst
- Trigger 524584: Swift detection of Algol
- GRB 120528C: MAXI/GSC detection
- GRB 120528B: MAXI/GSC detection
- GRB 120521C: MASTER optical limit
- Fermi GBM Trigger 358364818 is not a GRB
- GRB 120510A: MAXI/GSC detection of a burst
- IPN Triangulation of GRB 120427A
- Swift detection of 4U 1630-47
- GRB 120422A: MITSuME Ishigakijima upper limit
- GRB 120422A: 272 GHz observations from SMA
- GRB 120402A: optical upper limit
- GRB 120402A: MASTER follow up observations
- GRB 120403A: Swift detection of a burst
- GRB 120327A: MITSuME Ishigakijima Optical Upper Limits at 1 day afterthe burst
- GRB 120326A: Swift-BAT refined analysis
- GRB 120320A, Swift-BAT refined analysis
- GRB 120305A: MASTER-NET early optical observations
- GRB 120226A: Fermi-GBM and Fermi-LAT detections; LAT position retraction
- GRB 120219A: Swift-BAT refined analysis
- GRB 120211A: MITSuME Okayama and Ishigakijima Optical upper limits
- GRB 120211A: Swift detection of a burst
- LS I +61 303: Swift-BAT refined analysis
- GRB 120121A: Swift-BAT refined analysis
- GRB 120121A: Enhanced Swift-XRT position