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.
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"12311 results found.
- GRB 121123A: NIKA (New IRAM KID Arrays) millimetre observations at the 30-m Pico Veleta telescope
- GRB 121209A: Swift/UVOT Upper Limits
- GRB 121209A: MAXI/GSC detection
- GRB 121211A: Continued RATIR Optical and NIR Observations, Fading
- GRB 121211A: RATIR Optical and NIR Observations
- GRB121212A: Swift/UVOT Detection
- GRB 121212A: Swift detection of a burst
- GRB 121211A: Swift/UVOT Detection
- GRB 121211A: MITSuME Okayama Optical Observation
- GRB 121209A: Keck observations
- GRB 121209A: EVLA Observations
- GRB121209A: RATIR Optical and NIR Upper Limits
- GRB 121209A: GROND optical afterglow candidate
- GRB 121209A: UVOT Observation
- GRB 121202A: Swift/UVOT Upper Limits
- GRB121202A: Swift/UVOT Observations
- GRB 121201A: GROND afterglow observations and photometric redshift
- GRB 121201A: Swift/UVOT Detection
- GRB 121128A: MITSuME Akeno Optical upper limits
- GRB 121125A: optical upper limit
- GRB 121128A: Swift/UVOT Detection
- GRB 121123A: Swift/UVOT Observations
- GRB 121125A: Swift/UVOT Detection
- GRB 121125A: MASTER-NET optical observations
- GRB 121123A: MASTER-NET optical limit
- GRB 121108A: optical upper limit
- Konus-Wind observation of GRB 121118B
- GRB 121117A: optical upper limit
- GRB 121117A: Swift/UVOT Observations
- GRB 121117A: MASTER prompt optical limit
- GRB 121117A: BOOTES-3 early optical upper limit
- GRB 121108A: Swift/UVOT Upper Limits
- GRB 121108A: Xinglong TNT upper limit
- GRB 121108A: MITSuME Ishigakijima upper limits
- GRB 121108A: MASTER early prompt optical limit
- GRB 121108A: Swift detection of a burst
- GRB 121028A: Swift/UVOT Upper Limits
- GRB 121102A: Swift/UVOT Upper Limits
- GRB 121031A: Swift/UVOT Upper Limits
- GRB 121025A: Confirmation of the X-ray afterglow
- GRB 121102A: Swift detection of a burst
- GRB 121027A: sub-mm upper limit
- GRB 121027A: Swift/UVOT Possible Detection
- GRB 121027A: MASTER early prompt optical limit
- GRB 121028A: MITSuME Okayama Optical upper limits
- GRB 121028A: Swift detection of a burst
- GRB 121027A: MAXI/GSC detection 40 minutes after the Swift Trigger
- GRB 121027A: Swift detection of a burst
- GRB 121024A: Swift/UVOT Observations
- GRB 121024A: MITSuME Ishigakijima upper limits
- GRB 121024A: MITSuME Okayama Optical upper limits
- GRB 121025A: MAXI/GSC detection
- Swift Trigger 536502 is likely a noise fluctuation in coincidence with SAX J1818.6-1703
- GRB 121017A: Swift/UVOT Upper Limits
- 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