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"26335 results found.
- GRB070125 redshift request
- IPN localization of GRB070124 (short duration, hard spectrum)
- GRB 070110: Ep,i - Eiso correlation
- GRB 070107: Suzaku WAM observation of the prompt emission
- GRB070110: Swift XRT Team refined analysis
- GRB 070110, Swift-BAT refined analysis
- GRB070107 Swift/UVOT Observations of a Fading Optical Afterglow
- GRB 070110: Swift detection of a burst with a possible optical afterglow
- GRB 070107: Possible UVOT Afterglow
- GRB 070107, Swift-BAT refined analysis
- GRB 070107: Swift detection of a burst
- VLA observation of GRB 061222B
- VLA detection of GRB 061222A
- GRB070103: APO SPIcam i' and z' limits
- GRB070103: KPNO 4m+FLAMINGOS J limit
- GRB 070103: Swift/UVOT Upper limits
- GRB070103: Swift XRT refined analysis
- GRB 070103, Swift-BAT refined analysis
- GRB 070103: NOT observations
- GRB 070103: TAROT Calern observatory optical observations
- Retractions of previous Swift-BAT triggers
- erratum : SDSS Pre-burst Observations of GRB061126
- GRB 061210: Swift/XRT Astrometry Correction
- GRB 050826: MDM Redshift
- GRB 061222A: Confirmation of Gemini Afterglow Candidate
- GRB 061222A: Xinglong Optical Limit
- GRB 061222A: Gemini Afterglow Candidate
- GRB 061222B, Swift-BAT refined analysis
- GRB061222A Swift/UVOT: Upper Limits
- GRB 061222B: Swift/UVOT Upper limits
- GRB 061222B: Observation with the KANATA 1.5m telescope
- GRB 061222A: Observation with the KANATA 1.5m telescope
- GRB 061222B: BOOTES-IR optical observations
- GRB 061222B: SARA upper limit
- GRB 061217: Magellan host galaxy redshift
- GRB 061222A, Swift-BAT refined analysis
- GRB 061222B: REM NIR/optical observations
- GRB 061222B: TAROT La Silla observatory optical observations
- GRB 061222B: Swift detection of a burst
- GRB 061222b: optical afterglow
- GRB 061222A: Prompt ROTSE-III Optical Limits
- GRB 061222: Swift detection of a burst
- GRB 061218: TAROT La Silla observatory optical observations
- GRB 061217: TAROT Calern observatory optical observations
- GRB 061218: TORTOREM optical upper limits
- GRB 061218, Swift-BAT refined analysis
- GRB061217: VLT NIR observations
- GRB 061218, SMARTS optical/IR observations
- GRB 061218: REM prompt observations
- Swift triggers (#251863) on a possible burst
- GRB061217: Swift/UVOT refined analysis.
- GRB 061217: optical observations at Calar Alto
- GRB061217 - Swift/XRT refined analysis
- GRB 061217, Swift-BAT refined analysis
- GRB 061217: Magellan Observations
- GRB 061217: REM prompt observations
- GRB 061217: ROTSE-III Optical Limits
- GRB061210: Swift/UVOT observations
- GRB 061210: Swift XRT analysis - Possible counterparts
- GRB 061210: Gemini/GMOS Observations
- GRB 061126: Radio Observations
- GRB061210: Radio Observations
- GRB 061202: Suzaku WAM observation of the prompt emission
- GRB 061210, Swift-BAT refined analysis of the SHB
- Optical Afterglow observations of GRB 061126
- GRB 060926: MASTER: discovery of the optical flare
- GRB 061201: UVOT Observations of a Fading Optical Afterglow
- GRB 061202: TORTOREM optical upper limits
- GRB 061201: VLT optical decay
- GRB 061201: SOAR Confirmation of Candidate Afterglow
- GRB061202: FRAM early follow-up limit
- GRB061202 optical limit by "Pi of the Sky"
- GRB061202: optical/NIR observations with REM
- GRB061202: Swift/UVOT Upper Limits
- GRB 061202, Swift-BAT refined analysis
- GRB 061202: Swift detection of a burst
- GRB 061201: VLT optical observations
- GRB 061201: Initial UVOT Observations
- GRB 061201, Swift-BAT refined analysis of the SHB
- GRB 061201: Swift detection of a short hard burst
- INT+WFC observations of GRB 061126
- Swift XRT on-board boresight update
- GRB 061126: optical observation
- GRB 061126: Tautenburg afterglow observations
- GRB061126: Optical afterglow observations from MIRO
- GRB061126: Optical afterglow observations from MIRO
- GRB 061126 : SDSS Pre-Burst Observations
- GRB 061126: Swift-XRT refined analysis
- GRB 061126: Swift/UVOT Observations
- GRB 061126, Swift-BAT refined analysis
- GRB 061126: Early Detection of the IR Afterglow
- GRB 061126: Swift/UVOT Afterglow Detection
- GRB 061122: Candidate Optical Afterglow
- GRB 061121: Ep,i - Eiso correlation
- GRB061122: Swift/UVOT Optical Observations
- GRB061121: P60 Observations
- Radio detection of GRB 061121
- GRB061122: Swift-XRT position
- INTEGRAL results on GRB 061122
- Swift-BAT trigger 239987 is not a GRB