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"20488 results found.
- GRB 130903A: Swift-XRT observations
- GRB 130903A: GROND Upper Limits
- GRB 130831A: Swift/UVOT Observations
- GRB 130831A: Optical Observations via Virtual Telescope, follow-up
- GRB 130831A: RATIR Optical and NIR Observations
- GRB 130831A: Continued Skynet/PROMPT-SSO, PROMPT-CTIO and Yerkes-41 detections
- GRB 130831A: VLA Observations
- GRB 130831A: T100 observations
- GRB 130831B: Swift/UVOT Upper Limits
- GRB 130831B: GROND upper limits
- GRB 130831A: optical observations
- GRB 130831A: Optical Observations via Virtual Telescope
- GRB 130831A: Montarrenti Observatory optical observations
- GRB 130831A: Skynet/PROMPT-SSO detections
- GRB 130831A: Weihai optical observations
- GRB 130829A: AAO optical observations
- GRB 130828A: Swift XRT and UVOT observations
- GRB 130829A: NOT optical observations
- GRB 130828A Tiled Swift observations
- GRB 130822A: 5.8 GHz VLA upper limit
- GRB 130822A: Gemini Observations
- GRB 130822A: WHT ACAM observations
- GRB 130822A: Swift/UVOT Upper Limits
- GRB 130822A: Weihai optical upper limit
- GRB 130816A: Swift/UVOT Upper Limits
- GRB 130816B: Swift/UVOT Upper Limits
- GRB 130816B: GROND afterglow candidate
- GRB 130816A: GROND confirmation of afterglow
- GRB 130816A: REM NIR candidate afterglow
- GRB 130812A: Swift/UVOT Upper Limits
- GRB 130812A: GROND upper limits
- Correction to GCN Circ. 15086 "GRB130807A: Swift/UVOT observations"
- GRB130807A: Swift/UVOT observations
- GRB 130806A: Swift/UVOT Upper Limits
- GRB 130623A: GROND detection of the optical/NIR afterglow
- GRB130803A: GROND observations
- GRB 130803A: RATIR Optical and NIR Observations
- GRB130803A: GROND detection of possible host
- GRB 130803A: Swift/UVOT Upper Limits
- GRB 130803A: Faulkes Telescope South Observations
- GRB 130603B: Second epoch of HST WFC/F160W imaging
- GRB 130722A: RATIR Optical Observations
- GRB 130727A: Swift/UVOT Detection
- GRB 130727A: GROND observations
- GRB 130727A: Swift-XRT observations
- GRB 130727A: Swift-XRT and Swift-UVOT prompt observations
- GRB 130725B: Swift/UVOT Observations
- GRB130725B: REM-ROS2 optical observations
- GRB 130725A: Swift/UVOT Upper Limits
- GRB 130725A - Faulkes Telescope South Observations
- GRB 130725B: GROND Detection of the Optical/NIR Afterglow
- GRB 130725B: Swift/UVOT Detection of an Optical Counterpart
- GRB 130719A: Skynet/PROMPT observations
- Retraction of GCN Circ. 15020 (GRB 130722C Tiled Swift observations)
- GRB 130722A: Swift/UVOT Detection
- GRB 130722C Tiled Swift observations
- GRB 130722A: Skynet/GORT observations
- GRB 130716A: Gemini-North imaging
- GRB 130716A: UVOT Upper Limits
- GRB 130626A: Retraction of possible X-ray afterglow
- GRB 130702A: Maidanak optical observations
- GMRT radio detection of GRB 130702A
- GRB 130708A: Swift XRT and UVOT Observations
- GRB 130702A: TNG spectroscopic observations of the emerging supernova
- GRB 130702A: P200 Spectroscopic Confirmation of Associated Supernova
- GRB 130702A: Maidanak optical observations
- GRB130702A: NOT observation - the detection of an emerging supernova
- GRB 130702A: Continued RATIR Optical and NIR Observations
- GRB 130702A: Continued UVOT Observations
- GRB 130702A (= Fermi 394416326): correction of the GCN #14988 title
- GRB 130702Ð
- GRB 130702A: WSRT radio detection
- GRB130702A: Redshift of Afterglow Candidate iPTF13bxl
- GRB 130702A: further TNG observations
- GRB 130702A: NOT spectroscopy and redshift of the nearby bright galaxy
- GRB 130702A: further Swift-XRT observations
- GRB 130702A: Continued P60 observations
- GRB 130702A: RATIR Optical and NIR Observations
- GRB 130702A: NOT optical observations
- GRB 130702A: TNG optical observations
- GRB 130702A / Fermi394416326 : Nanshan optical observations
- Fermi GRB 130702A: Swift XRT and UVOT observations
- Fermi394416326: FTN detection
- Fermi394416326: iPTF detection of a possible optical afterglow
- GRB 130701A: P60 Observations
- GRB 130701A: Swift/UVOT Detection
- GRB 130701A: VLT/X-shooter redshift
- GRB 130701A: optical afterglow from the NOT
- GRB 130627B: Swift/UVOT Upper Limits
- GRB 130627A: Swift/UVOT Upper Limits
- GRB 130626A: KAIT Optical Observations
- GRB 130626A: RATIR Optical Observations
- GRB130627B: Swift/UVOT Observations
- GRB 130627B: Swift-XRT observations
- GRB 130626A: Swift-XRT possible detection and UVOT upper limits
- GRB 130627A: Swift-XRT observations
- GRB 130625A: Swift/UVOT Upper Limits
- GRB 130623A: Swift-XRT and UVOT observations
- GRB 130603B: First epoch of XMM-Newton observations
- Swift Trigger 558631: AAO optical observations