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"19572 results found.
- GRB 170205A: RATIR Optical and NIR Observations
- GRB 170202A: SMARTS optical/IR afterglow observations
- GRB 170205A: Swift detection of a burst with an optical counterpart
- GRB 170202A: Zadko observatory - Gingin optical observations
- GRB 170202A: Etelman Observatory optical observations
- GRB 170202A: RATIR Optical and NIR Observations
- GRB 170202A: SQUEAN Observation
- GRB 170202A: T100 observations
- GRB 170202A: Swift/UVOT Detection
- GRB 170202A: Enhanced Swift-XRT position
- GRB 170202A: NOT afterglow observations
- GRB 170202A: Zadko observatory - Gingin optical observations
- GRB 170202A: MASTGlobal ER-Net bright OT nonmonotonic light curve
- GRB 170202A: Mini-MegaTORTORA upper limits
- GRB 170202A: Swift detection of a burst with an optical afterglow
- GRB 170131A: Swift/UVOT Upper Limits
- GRB 170131A: Swift ToO observations
- GRB 170127B: Swift-BAT refined analysis
- GRB 170127C: Swift-XRT observations
- GRB 170127A: GROND Upper limits
- GRB 170124A: CALET Gamma-Ray Burst Monitor detection
- GRB 170127B: Swift/UVOT Upper Limits
- GRB 170127A: Swift/UVOT Upper Limits
- GRB 170127B: Enhanced Swift-XRT position
- GRB 170127B: NOT r-band upper limits
- GRB 170127A: Enhanced Swift-XRT position
- GRB 170127C: Tiled Swift observations
- GRB 170127C: Fermi-LAT detection
- LIGO/Virgo G270580: HAWC follow-up observations
- GRB 170127B: Swift detection of a short burst
- GRB 170127A: Swift detection of a burst
- GRB 170126A: Swift/UVOT Detection of a Fading Afterglow
- GRB 170126A: Enhanced Swift-XRT position
- GRB 170126A: Swift detection of a burst with an optical counterpart
- LIGO/Virgo G270580: Liverpool Telescope classification of EM candidates
- LIGO/Virgo G270580: Pan-STARRS coverage and 124 optical transients
- GRB 170121B: AbAO optical observations
- LIGO/Virgo G270580: CALET Observations
- GRB 170121B: Swift-XRT and UVOT observations
- GRB 170121B: Swift ToO observations
- LIGO/Virgo G270580: ATLAS coverage and 4 optical transients
- LIGO/Virgo G270580: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo G270580: Two optical counterpart candidates from CNEOST
- LIGO/Virgo G270580: Swift/BAT data search
- LIGO/Virgo G268556: Global MASTER Net 21 OTs detection
- LIGO/Virgo G270580: Mini-MegaTORTORA follow-up observations
- LIGO/Virgo G270580: Pan-STARRS and ATLAS observations of the skymap
- LIGO/Virgo G270580: Observations of initial skymap by Project Mini-GWAC of SVOM
- LIGO/Virgo G270580: AGILE MCAL and Super-AGILE Observations
- LIGO/Virgo G270580 ANTARES search
- GRB 170117A: Swift/UVOT Upper Limits
- GRB 170117A: Swift-XRT observations
- GRB 170117A: Swift ToO observations
- GRB 170115A : AbAO optical upper limit
- GRB 170115A: Swift/UVOT Upper Limits
- GRB 170112A : AbAO optical observations
- GRB 170115B: Tiled Swift observations
- GRB 170115A: Enhanced Swift-XRT position
- GRB 170115A: Swift detection of a burst
- GRB 170113A: GROND afterglow observations
- GRB 170113A: Swift/UVOT Observations
- GRB 170112A: Swift/UVOT Upper Limits
- GRB 170113A: Enhanced Swift-XRT position
- GRB 170113A: Swift detection of a burst with an optical counterpart
- LIGO/Virgo G268556: TZAC TAROT network observations with TRE/TCA/TCH
- GRB 170112A: RATIR Optical and NIR Observations
- GRB 170112A: Swift-BAT refined analysis
- GRB 161219B: afterglow and SN2016jca optical observations
- GRB 170111A: Swift/UVOT Upper Limits
- GRB 170112A: Swift-XRT observations
- GRB 170112A: REM optical/NIR observations
- GRB 170112A: Swift detection of a short burst
- GRB170111A: REM optical/NIR observations
- LIGO/Virgo G268556: Early SWASP limits of ATLAS17aeu
- LIGO/Virgo G268556: Additional GROWTH follow up observation of iPTF Optical Transient Candidates
- GRB 170111A: Enhanced Swift-XRT position
- GRB 170111A: Swift detection of a burst
- LIGO/Virgo G268556: Swift/BAT data search
- LIGO/Virgo G268556: Lijiang Observatory GMG Telescope Upper Limit on ATLAS17aeu
- LIGO/Virgo G268556: NOWT of EWE, Xinglong 0.6/0.9m, Xuyi 1m optical upper limits of ATLAS17aeu and a reminder of GCN 20394
- LIGO/Virgo G268556/GW170104: TNG observations of ATLAS17aeu
- LIGO/Virgo G268556: Pan-STARRS1 observations and summary of transient sources
- LIGO/Virgo G268556: GWAC_F60B (60cm) follow-up two events of EWE001 and EWE002
- LIGO/Virgo G268556: Swift/UVOT observations of ATLAS17aeu
- LIGO/Virgo G268556: CALET Observations
- LIGO/Virgo G268556: EWE001 and EWE002- two events close to GCN 20382 with the skymap
- LIGO/Virgo G268556/GW170104: Global MASTER Net second OT detection
- Swift Trigger 730874 is not astrophysical
- LIGO/Virgo G268556: HAWC follow-up of northern sky
- LIGO/Virgo G268556/GW170104: Global MASTER Net observations and first OT detection
- Swift Trigger 730513 is not an astrophysical event
- LIGO/Virgo G268556: ATLAS imaging of the skymap
- LIGO/Virgo G268556: AGILE MCAL and Super-AGILE Observations
- LIGO/Virgo G268556: Fermi-LAT search for high-energy gamma-ray counterpart
- LIGO/Virgo G268556: Mini-MegaTORTORA follow-up observations
- LIGO/Virgo G211117 / GW151226: LOFAR follow-up
- LIGO/Virgo G268556: ANTARES search
- LIGO/Virgo G268556: observation regions by Project Mini-GWAC of SVOM
- LIGO/Virgo G268556: INTEGRAL search of temporally coincident prompt hard X-ray emission
- LIGO/Virgo G268556: Fermi GBM Observations