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"20960 results found.
- LIGO/Virgo G184098: Correction for GCN Circular 18361
- GRB 160216A: Swift/UVOT Upper Limits
- GRB 160131A: second epoch observations with the GMRT
- Low frequency GMRT observations of GRB 160131A
- GRB 160206A: Kiso/KWFC optical observations
- LIGO/Virgo G211117: LOFAR follow-up
- GRB 160131A: TSHAO optical observations
- GRB 151215A: TAROT Calern observatory very early optical detection
- GRB 160206A: Swift/UVOT observations
- GRB 160203A: Zadko observatory - Gingin optical detection
- GRB 160206A: GROND Observations
- GRB 160206A: Swift-XRT observations
- GRB 160206B: iPTF P48 Observations and Optical Transient Candidates
- GRB 160206A: Tiled Swift observations
- GRB 160131A: TSHAO optical observations
- GRB 160131A: Mondy optcial observations
- GRB 160203A: TSHAO optical observations
- GRB 160203A: RATIR Optical Observations
- GRB 160131A: RATIR Optical Observations
- GRB 160203A: Skynet PROMPT-CTIO observations of the optical afterglow
- GRB 160203A: TAROT La Silla - TAROT Calern - Zadko observations
- GRB 160203A: Swift/UVOT Detection
- The bright GRB160203A: X-shooter spectroscopy and redshift
- GRB 160203A: LCOGT-Cerro Tololo optical afterglow confirmation
- GRB 160203A: GROND Afterglow Candidate
- GRB 160131A: VLA detection
- GRB160131A: NOEMA detection of the millimetre afterglow
- GRB 160131A: Optical observations from T150 OSN
- GRB 160131A: AbAO optical observations
- GRB 160131A: Mondy optical observations
- GRB 160131A Swift/UVOT Detection
- GRB 160131A: GROND Detection of the Optical/NIR Afterglow
- GRB 160131A: GTC spectroscopy of the afterglow
- GRB 160131A: TNG spectroscopic observations and redshift
- GRB 160131A: Bassano Bresciano Observatory optical observations
- GRB 160131A: Khureltogot optical observations
- GRB 160131A: TNG optical observations
- GRB 160131A: iTelescope optical observations
- GRB 160131A: LCOGT-SSO optical observations
- GRB 160131A: RATIR Optical Observations
- GRB 160131A: Xinglong 60cm WFT optical observation
- GRB 160131A: LCOGT-FTN optical afterglow observations
- GRB 160127A: RATIR Optical Observations
- GRB 160127A: Khureltogot optical observations
- GRB 160127A: VLA Detection
- GRB 160127A: LCOGT-Sutherland optical upper limit
- GRB 160127A: Swift/UVOT Detection
- GRB 160123A: TAROT La Silla observatory optical observations
- GRB 160127A: RATIR Optical Observations
- GRB 160127A: TAROT La Silla observatory optical light curve
- LIGO Virgo G211117: MWA Observations
- GRB 160123A: GROND Upper limits
- GRB 160121A: RATIR Optical Observations
- GRB 160123A: NOT J-band observations
- GRB 160123A: Swift/UVOT Upper Limits
- GRB 160121A: RATIR Optical Observations
- GRB 160121A: Swift/UVOT Upper Limits
- GRB 160121A: GROND Afterglow observations
- GRB 160117B: RATIR continued observations
- LIGO/VIRGO G184098: Summary of VLA results for iPTF15cyk
- GRB 160121A: MASTER-Amur observations
- GRB 160117A: Swift-XRT afterglow detection
- GRB 160119A: VLA Detection
- GRB 160117B: VLA Detection
- GRB 160117B: further RATIR observations
- GRB 160119A: afterglow confirmation from the NOT
- GRB 160119A: Swift/UVOT Upper Limits
- LIGO/Virgo G184098: MASTER final result
- GRB 160119A: GROND optical/NIR afterglow observations
- GRB 160119A: RATIR Optical and NIR Observations
- GRB 160117B: RATIR Optical and NIR Observations
- GRB 160117B: further NOT optical observations of the afterglow
- GRB 160119A: NOT and GTC afterglow candidate
- GRB 160117A: Swift/UVOT Upper Limits
- GRB 160104A: ISON-Ussuriysk optical observations
- GRB 160117A: Swift-XRT observations
- GRB 160117B: GROND optical/NIR afterglow observations
- GRB 160117B: VLT/X-shooter spectroscopy
- GRB 160117B: iTelescope T17 optical observations
- GRB 160117B: NOT optical afterglow observations
- GRB 160117B: Swift/UVOT Detection
- GRB 160117B: LCOGT-SSO optical observations
- GRB 160117B: MASTER-Amur OT observations
- LIGO/Virgo G211117: Preliminary VLA observation summary of PS15dpn
- LIGO/Virgo G211117: Further Swift-XRT sources
- GRB 160113A: Swift-XRT observations
- GRB 160113A: Swift ToO observations
- GRB 160113A: iPTF P48 Observations and Optical Transient Candidates
- GRB 160104A: Swift/UVOT Detection
- LIGO/Virgo G211117: Swift observations of PS15dpn
- LIGO/Virgo G211117: iPTF Observations of PS15dpn
- LIGO/Virgo G211117: PESSTO classification of MASTER J165420.77-615258
- LIGO/Virgo G211117: VLA follow-up
- LIGO/Virgo G211117: Pi of the Sky observations
- LIGO/Virgo G211117: VISTA imaging
- GRB 160104A: Continued MITSuME Akeno Optical Observation
- LIGO/Virgo G211117: Subaru Hyper Suprime-Cam follow-up observation
- LIGO/Virgo G211117: MASTER OT in ESO138-006 galaxy
- LIGO/Virgo G211117: Further Swift-XRT sources
- GRB 160104A: Nishi-Harima MINT Observations