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"12057 results found.
- GRB 121017A: GROND Observations
- GRB 121017A: Swift detection of a burst
- PdB IRAM observation of GRB 121011A
- GRB 121011A: Swift/UVOT Detection
- Swift-BAT refined analysis of the SGR 1806-20 outburst (trigger 535747)
- GRB 121011A: MASTER-Net early OT light curve
- Trigger 535733: Swift possible detection of SAX J1828.5-1037
- GRB 120927A: optical upper limit
- GRB 121001A: GROND Afterglow Confirmation
- GRB 121001A: Swift/UVOT Upper Limits
- GRB 121001A: MASTER optical observations
- Swift Trigger 535026: Galactic Transient or possible GRB
- GRB 120927A: Swift/UVOT Upper Limits
- GRB 120927A: GROND upper limits
- GRB 120927A: Swift detection of a burst
- GRB 120923A: optical upper limit
- GRB 120923A: MITSuME Okayama Optical upper limits
- GRB 120923A: GROND Upper limits
- GRB 120922A: Swift/UVOT Detection
- GRB 120923A: Swift/UVOT Upper Limit
- GRB 120923A: Swift detection of a burst
- GRB 120922A: Swift detection of a burst
- GRB 120919B: MASTER prompt optical observations
- GRB 120919A: Swift/UVOT Upper Limits
- Swift Trigger 534017 is probably not real.
- Corrections to the Fermi-LAT upper limits for GRB 120807A, 120908A, 120909A, and 120911A
- Swift Trigger 533836 is a new Galactic transient
- GRB 120911A: optical upper limit CrAO
- GRB 120911A: optical upper limit ISON-NM
- GRB120911A: MITSuME Okayama Optical upper limits
- GRB 120911A: Fermi/LAT upper limit
- GRB 120911A: Swift/UVOT Upper Limits
- GRB 120907A: SMA upper limits
- GRB 120908A and GRB 120909A : Fermi/LAT upper limit
- GRB 120908A: Swift Observations
- GRB 120909A: Pi of the Sky upper limits
- GRB 120909A: Swift/UVOT Detection
- GRB 120908A: MAXI/GSC detection
- GRB 120907A: EVLA observations
- GRB 120907A: Swift/UVOT Detection
- GRB 120819A: optical upper limit
- GRB 120830A: Further Swift Observations
- GRB 120830A: Fermi GBM observation
- GRB 120830A: early MASTER optical limit
- Fermi trigger 368003226 : MASTER optical observations
- GRB 120819A: Swift/UVOT Upper Limits
- GRB 120817A: Swift/UVOT Upper Limits
- GRB 120821A: Swift/UVOT Upper Limits
- GRB 120821A: GROND upper limits
- GRB 120819A: MITSuME Ishigakijima upper limits
- GRB 120819A: MITSuME Okayama Optical upper limits
- GRB 120819A: MASTER optical observations
- GRB 120819A: Swift detection of a burst
- GRB 120817B: Swift-XRT observations
- GRB 120816A: Swift/UVOT Detection of the Optical Afterglow
- GRB 120815A: MASTER-ICATE observations
- GRB 120816A: optical upper limit
- GRB 120815A: Swift/UVOT Detection of the Optical Afterglow
- GRB 120816A: Swift detection of a burst
- GRB 120811A: Swift/XRT-UVOT Obseravations
- GRB 120811C: EVLA Observations
- GRB 120811C: Swift/UVOT Detection
- Trigger 530588: Swift detection of XMM J174457-2850.3
- GRB 120803A: optical upper limit
- GRB 120807A: Swift/UVOT Upper Limits
- GRB 120803A: Confirmation of the X-ray afterglow
- GRB 120804A: ATCA 34GHz upper limit
- GRB 120807A: Fermi/LAT upper limit
- GRB 120804A: ATCA 34GHz upper limit
- GRB 120805A: Swift/UVOT Upper Limits
- Swift trigger 530214: uncertain if real or not
- GRB 120802A: Swift/UVOT Upper Limits
- GRB120805A: Liverpool Telescope observations
- GRB 120804A: MITSuME Okayama Optical upper limits
- GRB 120804A: Swift/UVOT Upper Limits
- GRB 120804A: GROND upper limits
- GRB 120802A: EVLA Observations
- GRB 120803B: MITSuME Okayama Optical upper limits
- GRB 120803A: MITSuME Okayama Optical upper limits
- GRB 120803B: MITSuME Akeno Optical upper limits
- GRB 120803B: Swift detection of a burst
- GRB 120803A: Swift detection of a possible burst
- GRB 120802A: GRT Optical Observation
- GRB 120802A: MASTER optical observations
- GRB 120802A: optical uper limit in ISON-NM observatory
- GRB 120802A: Swift detection of a burst
- GRB 120729A: EVLA Observations
- GRB 120729A: Swift/UVOT Detection
- GRB 120729A: Xinglong TNT optical upper limit
- GRB 120728A: Swift/UVOT Upper Limits
- GRB 120728A: Swift detection of a burst
- Swift Trigger 528925 is probably a noise fluctuation
- GRB 120722A: optical upper limit
- GRB 120724A: Swift/UVOT Detection of the Optical Afterglow
- GRB 120724A: Swift detection of a burst
- GRB 120722A: Swift/UVOT Upper Limits
- GRB 120722A: Correction for GCN circ.13500
- GRB 120722A: Swift detection of a burst
- GRB 120711A: ATCA 34GHz final observations (upper limit)
- GRB 120714B: Swift/UVOT Detection