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"
675 results found.
- GRB 170306A: GROND observations
- GRB 170214A: GROND detection in all bands
- GRB 170209A: GROND confirmation of MASTER afterglow
- GRB 170208B: Swift/UVOT Upper Limits
- GRB 170208B: RATIR Optical and NIR Observations
- Correction to GCN 20640: GRB 170208B: GROND observations
- GRB 170208B WHT nIR candidate afterglow
- GRB 170208B: GROND observations
- GRB 170127A: GROND Upper limits
- GRB 170113A: GROND afterglow observations
- GRB 161220A: GROND Upper Limits
- GRB 161219B: GROND afterglow observations
- GRB 161214A: GROND afterglow observations
- GRB 161104A: Magellan imaging and spectroscopy
- GRB 161104A: Gemini South optical observations
- GRB 161104A: GROND observations
- GRB 161023A: GROND Observations
- GRB 161001A: MASTER-OAFA and MASTER-SAAO early optical observations
- GRB 161001A: GROND afterglow candidate
- GRB 160927A: NOT optical observations
- GRB 160927A: GROND Observations
- GRB 160804A: GROND observations
- GRB 160712A: Further GROND observations
- GRB 160712A: RATIR Optical and NIR Observations
- GRB 160712A: GROND observations
- GRB 160625A: GROND upper limits
- GRB 160630A: GROND Afterglow Detection
- GROND observations of GRB 160622A/SNR RCW 103/SGR 1617-5103
- GRB 160607A: GROND confirmation of the afterglow
- GRB 160506A: GROND upper limits
- GRB 160501A: GROND Upper limits
- GRB 160425A: Swift/UVOT Detection
- GRB 160422A: GROND NIR afterglow detection
- GRB 160425A MASTER notices: possible host galaxy in the optical error-box
- GRB 160425A: GROND observation
- GRB 160412A: GROND upper limits
- GRB 160411A: GROND Optical/NIR upper limits
- GRB 160410A: Swift/UVOT Detection
- GRB 160410A: GROND optical detection
- GRB 160325A: GROND Upper Limits
- GRB 160314A: Continued RATIR Optical and NIR Observations
- GRB 160314A: GROND optical/NIR observations
- GRB 160228A: GROND afterglow confirmation and X-shooter host candidate redshift
- GRB 160303A: Continued optical monitoring from NOT
- GRB160303A: further GROND observations
- GRB 160303A: Continued RATIR Optical and NIR Observations
- GRB 160303A: GROND Optical Detection
- GRB 160228A: Swift/UVOT Upper Limits
- GRB 160228A: RATIR Optical and NIR Observations
- GRB 160228A: MASTER-Amur prompt observations
- GRB 160228A: GROND Afterglow Candidate
- GRB 160223A: Swift-XRT afterglow detection
- GRB 160223A: GROND optical/NIR afterglow
- GRB 160221A: GROND upper limits
- GRB 160220B: Further GROND Observations
- Further Swift/UVOT observations of GRB 160220B
- GRB 160220B: GROND Observations
- GRB 160220A: GROND Optical/NIR Upper Limits
- GRB 160206A: GROND Observations
- GRB 160203A: GROND Afterglow Candidate
- GRB 160131A: GROND Detection of the Optical/NIR Afterglow
- GRB 160123A: GROND Upper limits
- GRB 160121A: RATIR Optical Observations
- GRB 160121A: GROND Afterglow observations
- GRB 160117B: further RATIR observations
- GRB 160119A: GROND optical/NIR afterglow observations
- GRB 160117B: GROND optical/NIR afterglow observations
- GRB151215A: Swift/UVOT detection
- GRB 151215A: GROND Detection of the Optical/NIR Afterglow
- GRB 151212A: GROND Optical Afterglow Candidate
- GRB 151210A: GROND Afterglow Confirmation
- GRB 151205B: Deep GROND Upper limits
- GRB 151205A: Garching Telescope Upper Limit
- GRB 151127A: GROND K-band upper limit
- GRB 151120A: Swift-XRT afterglow detection
- GRB 151120A: GROND optical/NIR afterglow
- GRB 151114A: GROND Detection of the Optical/NIR Afterglow Candidate
- GRB 151112A: GROND photometric redshift and i'-band prediction
- GRB 151111A: GROND confirmation of the afterglow and photometric redshift estimate
- GRB 151112A: Swift/UVOT Upper Limits
- GRB 151112A: GROND Detection of the Optical/NIR Afterglow Candidate
- GRB 151111A: GROND marginal detection of a afterglow candidate
- GRB 151031A: GROND observation
- GRB 151029A: GROND afterglow observations
- GRB 151027B: GROND Optical/NIR Afterglow Detection
- LIGO/Virgo G194575: GROND multi-color observations
- GRB 151023A: RATIR Observations
- GRB 151023A
- GRB 150915A: NOT observations of a brightening afterglow
- GRB 150915A: Swift UVOT upper limits
- GRB 150915A: GROND detection of an optical counterpart candidate
- GRB 150911A: GROND Upper Limits
- GRB 150910A: NOT observations of the afterglow
- GRB 150910A: GROND observation of the afterglow
- GRB 150907B: GROND Upper Limits
- GRB 150831A: GROND Upper Limits
- GRB 150821A: GROND afterglow observations
- GRB 150514A: GROND Bright Afterglow Confirmation
- GRB 150430A: GROND Upper Limits
- GRB 150428A: Danish1.56m optical observations