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"26299 results found.
- GRB 081104 : Faulkes Telescope South observations
- GRB 081104: Swift-XRT position
- GRB 081104: Swift detection of a burst
- GRB 081102: MASTER prompt optical limit
- GRB 081102: Swift-XRT refined analysis
- GRB 081102: Swift/UVOT refined analysis
- GRB 081102: Swift-BAT refined analysis
- GRB 081102: Swift detection of a burst
- GRB 081101 (or SGR 0623-0006 ): Fermi GBM detection
- SGR 0623-0006 or GRB 081101: Swift-XRT refined analysis
- SGR 0623-0006 or GRB 081101: Swift-BAT/-XRT refined analysis
- Swift-BAT triggered on a probable GRB 081101 (trigger=333320)
- GRB 081029: UVOT Detection of the Optical Afterglow
- GRB 081029: PROMPT Detections
- GRB 081029: Swift-BAT refined analysis
- GRB 081025: Suzaku WAM observation of the prompt emission
- GRB 081024B: Suzaku WAM observation of the prompt emission
- GRB 081028: GROND Confirmation of the Optical/NIR Afterglow
- GRB 081029: GROND Detection of the Optical/NIR Afterglow
- GRB 081029: ROTSE-III Detection of Optical Counterpart
- GRB 081029: Swift detection of a burst
- GRB 081028B: Fermi GBM detection
- GRB 081021: Fermi GBM detection
- GRB081028: UVOT detection of a brightening afterglow
- Swift UVOT observations of GRB081028
- GRB 081028: Swift-XRT refined analysis
- GRB 081028, Swift-BAT refined analysis
- GRB 081028: TAROT Calern observatory optical observations
- GRB 081028: GROND Detection of the Optical/NIR Afterglow Candidate
- GRB 081028: Swift detection of a burst
- Swift UVOT observations of GRB081025
- Swift UVOT observations of GRB081024B
- GRB 081025: Swift-XRT position
- GRB 081024B: Swift-XRT observations
- GRB 081024B: Fermi Gamma-ray Burst Monitor detection
- Fermi-LAT observation of GRB 081024B
- Swift UVOT observations of GRB 081024
- GRB 081024, Swift-BAT refined analysis
- GRB 081024: Faulkes Telescope North optical observations
- GRB 081024: Early Super-LOTIS Observations
- GRB 081024A: ROTSE-III Optical Limits
- GRB 081024: Swift detection of a burst
- GRB 081022, Swift-BAT refined analysis
- GRB 081016A: Swift-XRT refined analysis
- GRB 081022: Swift detection of a burst
- Swift trigger 332287 is not a GRB
- Swift detection of a possible burst (trigger 332287)
- GRB 081017, Swift-BAT refined analysis
- GRB 081017: Swift detection of a burst
- GRB 081016B, Swift-BAT refined analysis
- GRB 081016B: Swift/UVOT Upper Limits
- GRB 081011: Swift XRT refined analysis
- GRB 081016B: Swift-XRT Team refined Analysis
- GRB 081016B: ROTSE-III Optical Limits
- GRB 081016B: Swift detection of a burst
- GRB 081016: Swift-XRT candidate afterglow detection
- Swift detection of flare on CC Eri
- Trigger 331721 Due to Swift startracker loss-of-lock
- Detection of flare star Algol in Swift-BAT slew data
- GRB 081009: Fermi GBM detection
- Swift-BAT triggered on the flare star Algol
- GRB 081012: Fermi GBM detection
- GRB 081007 and GRB 081007B: Fermi GBM detection
- GRB 081012: Swift/UVOT analysis of initial observations
- GRB 081012: Swift/XRT detection
- GRB 081012, Swift-BAT refined analysis
- GRB 081012: ROTSE-III Optical Limits
- GRB 081012: Swift detection of a burst
- GRB081011: UVOT detection of an optical afterglow
- GRB 081011: Swift/XRT detection
- GRB 081011, Swift-BAT refined analysis
- GRB 081011: Swift detection of a burst
- GRB 081007: Rapid PROMPT Detections
- GRB 081008, Swift-BAT refined analysis
- GRB 081008: Swift-XRT Refined Analysis
- GRB081008: Swift/UVOT observations
- GRB 081008: Swift detection of a burst with optical afterglow
- GRB 081008: ROTSE-III Detection of Optical Counterpart
- GRB081006B: Fermi GBM detection
- GRB081006: Fermi GBM detection
- GRB081007: Swift/UVOT Observations
- GRB 081007, Swift-BAT refined analysis
- GRB 081007: Early RAPTOR measurements of optical counterpart
- GRB 081007: Swift-XRT Team refined analysis
- GRB 081007: Swift detection of a burst with optical afterglow
- GRB081003C: GLAST Burst Monitor detection
- Fermi GBM detection of additional bursts from AXP 1E1547.0-5408
- GRB 081003B: TAROT Calern observatory optical observations
- AXP 1E 1547.0-5408: Swift/UVOT Upper Limits
- GRB 081003B: Swift-XRT upper limit
- GRB 081003A: OSN optical observations
- AXP 1E1547.0-5408: Swift-XRT Team refined analysis
- GRB 081003A: Swift-XRT Team position and analysis
- Swift-BAT refined analysis of AXP 1E1547.0-5408 (Trigger 330353)
- GRB 080928: Fermi GBM detection
- AXP 1E1547.0-5408 (SGR 1550-5418): Fermi GBM detection
- SGR 1550-5418 = AXP 1E1547.0-5408 (Trigger 330353)
- Swift discovery of a new Soft Gamma Repeater SGR 1550-5418
- Trigger 330353: Swift detection of a Galactic short soft burst
- GRB 080925: Suzaku WAM observation of the prompt emission