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"8472 results found.
- GRB 100518A: Swift target of opportunity observation of the INTEGRAL burst
- GRB 100514A: optical afterglow confirmation
- GRB 100514A: Swift-BAT refined analysis
- GRB 100514A: Swift detection of a burst
- GRB 100513A: PAIRITEL continued observations and confirmation of fading
- GRB 100513A: SARA-N Upper Limit
- GRB 100513A: PAIRITEL NIR afterglow candidate
- GRB 100513A: Swift detection of a burst
- Swift-BAT trigger 421695 is likely not astrophysical
- Trigger 421695: Swift detection of a possible burst
- GRB 100508A: Swift detection of a burst
- An SGR-like burst from the magnetar 1E 1841-04.5 in Kes 73
- GRB 100504A: Swift detection of a burst
- Trigger 421072: Possible Swift detection of a GRB or transient
- GRB 100414A : WSRT Radio Detection
- Konus-Wind observation of GRB 100423A
- GRB 100424A: CrAO optical observations
- GRB 100424A: NIR Afterglow Confirmation
- GRB 100424A: Gemini/NIRI H-band observations
- GRB 100425A: GROND afterglow observation
- GRB 100424A: Gemini/NIRI Candidate Afterglow
- GRB 100425A: candidate optical afterglow from the VLT
- GRB 100425A: Swift detection of a burst
- GRB 100424A: Swift detection of a burst
- Trigger 420256: Swift detection of a possible GRB
- GRB 100418A: WSRT Radio Detection
- GRB 100420A: Swift detection of a burst
- GRB 100418A: Swift detection of a burst with a possible optical afterglow
- GRB 100414A: Gemini-N candidate and redshift
- GRB 100414A: Enhanced Swift-XRT position of candidate afterglow
- GRB 100414A: Palomar Transient Factory Observations
- GRB 100413A: Swift detection of a burst
- Spin down rate and inferred dipole magnetic field of the new soft gamma-ray repeater SGR 1833-0832
- IBAS Alert n. 5996: not a GRB
- GRB 100316A: R-band limit
- GRB 100331B: Swift/XRT possible afterglow candidate
- Fermi/GBM and Swift/BAT detection of a burst from SGR 1806-20
- SGR 1833-0832 is pulsed at 7.56 seconds
- SGR 1833-0832 is pulsed at 7.56 seconds
- Possible pulsation period in SGR 1833-0832
- GRB 100319A: Swift detection of a burst; possible SGR
- GRB 100316D: Pre-burst emission measured by BAT
- GRB 100316A: optical observations in CrAO
- GRB 100316D: Swift XRT enhanced position and further refined analysis
- GRB 100316C: GROND Detection of a Optical/NIR Afterglow Candidate
- GRB 100316D: GROND Detection of the Optical/NIR Afterglow Candidate
- GRB 100316D: Gemini/GMOS and VLT/X-shooter observations
- GRB 100316D: VLT/X-shooter observations
- GRB 100316A: TAROT Calern observatory optical observations
- GRB 100316A: Swift-BAT refined analysis
- GRB100316A: Swift/UVOT Upper Limits
- Trigger 416140 is almost certainly not a GRB
- GRB 100316D: Swift detection of a burst
- GRB 100316B: VLT/X-shooter redshift
- GRB 100316B: GROND Detection of the Optical/NIR Afterglow Candidate
- GRB 100316C: Swift detection of a burst
- GRB 100316B: Swift detection of a burst with optical counterpart
- GRB 100316 optical candidate from 1.23m CAHA telescope
- GRB 100316 optical candidate from 1.23m CAHA telescope
- GRB 100316A: Swift/UVOT Observations
- GRB 100305A: Swift/UVOT Upper Limits
- GRB 100305A: Gemini-N OT candidate
- GRB 100305A: P60 Observations
- GRB 100305A: Swift detection of a burst
- GRB 100302A: Optical observations at Crni Vrh
- GRB 1000302A : A possible afterglow candidate
- GRB 100302A: Swift detection of a burst
- GRB 100206A: optical observations in CrAO
- GRB 100206A: optical observations in Terskol
- GRB 100219A: VLT/X-shooter redshift
- GRB 100219A: Swift/UVOT Detection of the Optical Afterglow
- GRB 100219A: Pre-explosion imaging and host candidate
- GRB 100219A: Swift detection of a burst
- GRB 100213B: Swift-BAT refined analysis
- GRB 100213B: Swift detection of a burst
- GRB 100213A: Swift detection of a burst
- GRB 100212A: LOAO R-band Detection/V-band Observation
- GRB 100212A: candidate optical afterglow
- GRB 100212A: Swift detection of a burst
- GRB 100205A: Keck limits on an underlying host galaxy
- GRB 100205A: BOAO/LOAO zYJK observation
- GRB 100206A: Gemini-North observations
- GRB 100206A: Swift/UVOT Upper Limits
- GRB 100206A: PAIRITEL Photometry of Host Candidate
- GRB 100206A - Keck/LRIS Spectroscopy
- GRB 100206A: WHT candidate afterglow
- GRB 100206A: optical observations from Southern Spain
- GRB 100205A: GROND upper limits
- GRB 100206A: Pre-explosion imaging and host candidate
- GRB 100206A: Swift detection of a short hard burst
- GRB 100205A: Gemini-N + NIRI photometry
- GRB 100113A: Fermi GBM detection
- GRB 100205A Gemini-North IR afterglow candidate
- GRB 100205A: Swift detection of a burst
- GRB 100117A: candidate optical afterglow
- GRB 100117A: Optical object inside the revised XRT error circle
- GRB 100117A: Gemini South Imaging and CFHT Pre-Explosion Images
- GRB 100117A: Swift detection of a short hard burst
- GRB 100115A: Gemini-N photometry
- GRB 100115A: SARA Astrometry