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.
Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
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"26 results found.
- GRB 251230A: MeerLICHT afterglow detection
- Konus-Wind detection of GRB 251230A / EP251230a
- GRB 251230A: Mondy Optical Observations
- Swift GRB 251230A: Global MASTER-Net OT detection
- GRB 251230A/EP-WXT trigger 01709250693: Mephisto optical upper limits
- GRB 251230A / EP251230a: GECAM-B detection
- GRB 251230A / EP251230a: Insight-HXMT/HE detection
- GRB 251230A / EP251230a: SVOM/VT optical continued observations and upper limit
- GRB 251230A: GRANDMA/TAROT Early Detection
- GRB 251230A / EP251230a: further NOT optical observations revealing shallower decay or possible rebrightening
- GRB 251230A/EP251230a: Optical upper limit with Kinder observations
- GRB 251230A: 1.3m DFOT optical upper limit
- GRB 251230A: Swift-XRT refined Analysis
- EP251230a / GRB 251230A: refined analysis of the EP-WXT and EP-FXT observations
- GRB 251230A: Swift/UVOT detection
- GRB 251230A / EP251230a: NOT observations and spectroscopic redshift upper limit z < 2.2
- GRB 251230A: GOTO optical upper limit
- GRB 251230A / EP251230a: SVOM/VT optical observation
- GRB 251230A: Enhanced Swift-XRT position
- GRB 251230A: Early optical counterpart detection by LCO.
- GRB 251230A: Optical Observations via Virtual Telescope Project, Italy
- EP251230a / GRB 251230A: Einstein Probe detection of an X-ray transient
- GRB 251230A/EP#01709250693 (likely EP251230a): FTW optical and NIR observations
- Swift GRB 251230A: Global MASTER-Net observations report
- The EP-WXT trigger 01709250693/GRB 251230A: Las Cumbres detection of the optical counterpart
- GRB 251230A: Swift detection of a burst with a bright optical counterpart