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"20457 results found.
- GRB 130514A: RATIR Optical and NIR Observations
- GRB 130513A: RATIR Optical and NIR Observations
- GRB 130513A: Swift/UVOT Upper Limits
- GRB 130514A: Swift/UVOT Upper Limits
- GRB 130513A: GROND observations
- GRB 130514A: GROND optical-NIR afterglow discovery and photo-z
- GRB 130514A: P60 Observations
- GRB 130427A: Tautenburg 2nd epoch: No break, no clear SN
- GRB130508A: MASTER-Net optical observations
- GRB 130511A: Kanata/HOWPol optical observation
- GRB 130508A: Swift/UVOT Upper Limits
- GRB 130427A: host galaxy observations
- GRB 130508A: RATIR Optical and NIR Observations
- GRB 130427A: Keck/LRIS Observations
- GRB 130427A: Ten nights of Skynet/PROMPT/GORT observations
- GRB 130427A: Continued RATIR Optical and NIR Observations
- GRB 130505B: Further Swift observations
- GRB 130427A: Excess optical emission consistent with an emerging supernova
- GRB 130427A: Amateur observations from Sweden
- GRB 130505A: RATIR Optical and NIR Observations
- GRB 130505B: Swift Candidate Afterglow
- GRB 130505A: Tautenburg afterglow observations
- GRB 130427A: Tautenburg afterglow observations
- GRB 130427A: RHESSI observations
- GRB 130504C: further Swift-XRT observations
- GRB 130505A: optical observations
- GRB 130504C: Swift-XRT observations
- GRB 130427A: optical observations in CrAO
- Swift/UVOT observations of GRB130505A
- GRB 130505A: iTelescope T12 optical observations
- GRB 130505A: Xinglong TNT optical observations
- GRB 130505A; Weihai optical observations
- GRB 130504A: IAC80 optical candidate
- GRB 130504A: Bassano Bresciano Observatory optical upper limit
- GRB 130504A: Swift/UVOT Upper Limits
- GRB 130502B: possible TNG counterpart
- GRB 130427A: Non-observation of VHE emission with HAWC
- GRB130502A: MASTER-Net optical observations
- GRB 130502B: Swift/UVOT Upper Limits
- GRB 130502A: Swift/UVOT Upper Limits
- GRB 130502B: P60 Observations
- GRB 130502B Swift-XRT observations
- GRB 130502A: RATIR Optical and NIR Observations
- GRB 130427A: Pan-STARRS 1 optical observations
- GRB 130418A: TNG NIR observations
- GRB 130502A: OSN and IAC80 I-band observations
- GRB 130502A: z-band observations from GTC
- GRB 130502A: TNG candidate counterpart
- GRB 130502A: T100 Observations
- GRB 130427A: Predictions about the occurrence of a supernova
- GRB 130427A: KAIT optical observations
- GRB 130427A: SARA-N optical observations
- GRB 130427A: VLA 20 GHz detection
- GRB 130427A: ABT optical observations
- GRB 130427A: GMRT radio detection
- GRB 130427A: Continued GMG optical observations
- GRB 130427A: Nishi-Harima Optical Spectroscopic Observations
- GRB 130427A: Continued RATIR Optical and NIR Observations
- GRB 130427A: Challis Observatory optical observations
- GRB 130427A: Continued Skynet/PROMPT Observations
- GRB 130427A: further GMG observations
- GRB 130427A: Continued RATIR Optical and NIR Observations
- GRB 130425: MASTER-Net optical observations
- GRB 100728A: GROND host detection and X-shooter redshift
- GRB 130427A: Skynet/PROMPT Observations
- GRB 130427B: RATIR Optical and NIR Observations
- GRB 130427A: Nishi-Harima NIR Observations
- GRB 130427A: CARMA 3mm observations
- GRB 130427A optical time series
- GRB 130427A, Optical Observations
- GRB 130427A: Continued iTelescope T21 optical observations
- Konus-Wind observation of GRB 130427A
- GRB 130427A: SPI-ACS/INTEGRAL observations
- GRB 130427A: Continued RATIR Optical and NIR Observations
- GRB 130427A: CARMA 85 GHz detection
- GRB 130427A: SNUO/SOAO/BOAO Observation
- GRB 130427A: VLA 5 GHz detection
- GRB 130427A: NOT optical photometry and redshift
- GRB 130427A: T100 observations
- GRB 130427A: optical observations in CrAO
- GRB130427A: Swift/UVOT followup observations of an Optical Afterglow
- GRB 130427A: Zadko observatory - Gingin optical observations
- GRB 130427A: GMG optical observation
- GRB 130427A: Optical Observations
- GRB 130427A: RATIR Optical and NIR Observations
- GRB 130427A: Weihai optical observations
- GRB 130427A: iTelescope T11 optical observations
- GRB 130427A: Continued P60 follow-up of an extremely bright optical afterglow
- GRB 130427A: Gemini-North redshift
- GRB 130427A: PAIRITEL NIR Detections
- GRB 130427A: Faulkes Telescope North detection
- GRB 130427A: P60 early detection
- GRB 130427A: early optical observations
- GRB 130427A: P60 early nondetection
- GRB 130420A: Continued Skynet/GORT Observations/Detections
- GRB 130420B: CARMA and VLA radio observations
- Trigger 554491: Swift detection of a spike possibly from Sgr A*
- GRB 130420A: Continued RATIR Optical and NIR Observations
- GRB 130420A: ROTSE-III data analysis
- GRB 130420A: Continued RATIR Optical and NIR Observations