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"4256 results found.
- GRB 100628A: Gemini North Observations
- GRB100625A: GROND confirmation of constant source
- XRF 100616a : MAXI/GSC detection of a probable XRF
- GRB 100615A: Swift-BAT refined analysis
- GRB 100615A: NTT/Ultracam imaging
- GRB 100615A: Swift detection of a burst
- GRB 100614A: Liverpool Telescope Observations
- GRB 100514A: CrAO optical observations
- GRB 100528A: NOT optical observation
- GRB 100526A: Gemini/NIRI infrared afterglow candidate
- GRB 100514A: optical afterglow confirmation
- Swift-BAT trigger 421695 is likely not astrophysical
- Swift-BAT refined analysis of trigger 421262
- An SGR-like burst from the magnetar 1E 1841-04.5 in Kes 73
- INTEGRAL observations of Swift GRB trigger 421072
- GRB 100427A: Fermi GBM detection
- GRB 100424A: Gemini/NIRI H-band observations
- GRB 100423A: Swift-BAT refined analysis
- GRB 100423A: GROND discovery of afterglow
- GRB 100418A: WSRT Radio Detection
- GRB 100415A: MAXI/GSC detection of a probable GRB
- Spin down rate and inferred dipole magnetic field of the new soft gamma-ray repeater SGR 1833-0832
- Swift detection of LS V +44 17
- Fermi/GBM and Swift/BAT detection of a burst from SGR 1806-20
- SGR 1833-0832: Swift/UVOT Upper Limits
- SGR 1833-0832: Archival Chandra Observations
- SGR 1833-0832 is pulsed at 7.56 seconds
- SGR 1833-0832 is pulsed at 7.56 seconds
- Possible pulsation period in SGR 1833-0832
- Discovery of the Spin Period of SGR 1833-0832
- Probable SGR 1833-0832: Swift-XRT refined analysis
- Probable SGR 1833-0832: Enhanced Swift-XRT position
- Swift-XRT refined position of the probable new SGR 1833-0832
- Swift-BAT refined analysis of the probable new SGR 1833-0832
- GRB 100319A: Swift detection of a burst; possible SGR
- XRF 100315A: MAXI/GSC detection of a short X-ray transient
- GRB 100213A: Swift detection of a burst
- GRB 100212A: Fermi GBM detection
- GRB 100212A: Swift-BAT refined analysis
- GRB 100212A: Enhanced Swift-XRT position
- GRB 100212A: candidate optical afterglow
- GRB 100212A: Swift detection of a burst
- GRB 100206A, RIMOTS optical upper limits
- GRB 100113A: Fermi GBM detection
- GRB 100131A: Fermi GBM detection
- GRB 100116A: Fermi LAT detection
- GRB 100116A: Fermi GBM detection
- Swift Trigger #382159 is due to XTE J1752-223
- GRB 100103A: GROND Upper Limits
- GRB 100103A - UVOT-enhanced XRT position
- GRB 100103A: Swift/XRT position
- GRB 091123: Fermi GBM detection of a very long burst
- Konus-Wind observations of GRB 091117A
- GRB 091117A Detected in ground analysis of BAT data and IPN triangulation
- GRB 091029, SMARTS optical/IR afterglow observations
- GRB091024 optical observations
- GRB 091029: Gemini-South Redshift
- GRB 091029: GROND Detection of the Optical/NIR Afterglow
- GRB 090929A: Fermi GBM detection
- GRB 090715B: Skynet/PROMPT Detections
- GRB 090912: optical observation
- GRB 090915: Swift/UVOT detection of an optical afterglow candidate
- GRB 090915: Swift-XRT detection of a fading X-ray counterpart
- GRB 090912: Enhanced Swift-XRT position
- GRB 090912: Swift detection of a burst
- GRB 090910: Fermi GBM detection
- GRB 090829A: Suzaku WAM observation of the prompt emission
- GRB 090829B: Fermi GBM Detection
- GRB090829: Fermi GBM Detection
- GRB 090823: Confirmation of Swift-BAT position by BAT Slew Survey
- GRB 090817: aphotometry of USNO-B1.0 341-0096763
- GRB 090812, RIMOTS optical upper limits
- GRB 090728, RIMOTS optical upper limits
- IPN Triangulation of bright GRB 090720B
- GRB 090713: Fermi GBM detection
- GRB 090529: CrAO optical upper limit
- GRB 090529: MTM-500 optical observations
- Konus-Wind observation of GRB 090626
- GRB090618: HCT optical observations
- PAIRITEL observations of GRB 090618
- GRB 090618: OA behavior from KAIT
- GRB 090618: Swift detection of a bright burst with optical afterglow
- SGR 0418+5729 Fermi/GBM Detection of Pulsations
- RXTE Discovery of Pulsations from SGR 0418+5729
- Konus-RF observation of SGR burst 090605A
- Discovery of a new soft gamma repeater source, SGR 0418+5729
- GRB090529B: ROVOR Upper Limits
- GRB 090529C: Fermi GBM detection
- GRB 090529B: Fermi GBM detection
- GRB 090529: MITSuME optical observation
- GRB 090530: GRT Optical Observation
- GRB 090531: GROND upper limits
- GRB 090528B: Fermi GBM detection
- GRB 090529: optical observations
- GRB 090529: Xinglong TNT optical observation
- GRB 090519: NOT afterglow candidate
- GRB 090509, further Swift-BAT refined analysis
- GRB 090509: Swift-BAT refined analysis
- GRB 090323: optical observations
- GRB 090427: GROND observations