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"
24759 results found.
- 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
- GRB 170111A: Swift-BAT refined analysis
- GRB 170111A: SMARTS optical/IR observations
- GRB 170111A: Swift-XRT refined Analysis
- LIGO/Virgo G268556: Additional GROWTH follow up observation of iPTF Optical Transient Candidates
- GRB 161230A: POLAR Observation
- LIGO/Virgo G268556/GW170104: Campo Imperatore Observatory observations
- 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: Swift-XRT confirms that ATLAS17aeu is fading in X-rays
- LIGO/Virgo G268556: ATLAS17aeu position is consistent with GRB170105A
- LIGO/Virgo G268556/GW170104: 10.4m GTC spectroscopic observations of iPTF17fs
- LIGO/Virgo G268556/GW170104: TNG spectroscopic observations of iPTF17ck and iPTF17dz
- LIGO/Virgo G268556/GW170104: Lomonosov BDRG observations
- LIGO/Virgo G268556: Swift/UVOT observations of ATLAS17aeu
- LIGO/Virgo G268556: CALET Observations
- LIGO/Virgo G268556: AGILE-GRID preliminary analysis
- 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: Swift-XRT detection of ATLAS17aeu
- GRB 170105A: AstroSat CZTI detection
- GRB 170105A: POLAR Observation
- LIGO/Virgo G268556: Updated sky map from gravitational-wave data
- LIGO/Virgo G268556: HAWC follow-up of northern sky
- LIGO/Virgo G268556: ATLAS17aeu - an unusual transient within the skymap
- 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: Swift-XRT sources
- LIGO/Virgo G268556: ANTARES search
- LIGO/Virgo G268556: observation regions by Project Mini-GWAC of SVOM
- GRB170104.78 MASTER-Net OT detection
- LIGO/Virgo G268556: INTEGRAL search of temporally coincident prompt hard X-ray emission
- LIGO/Virgo G268556: Fermi GBM Observations
- GRB 170102A: POLAR observation
- GRB 170101B: POLAR observation
- GRB 161228C: POLAR observation
- GRS 1716-249/GRO J1719-24/V2293 Oph, Swift-BAT refined analysis
- GRB 170101A: POLAR observation
- GRB 161229A: POLAR observation
- GRB 170101A: Swift-BAT refined analysis
- GRB 170101B: Fermi GBM detection
- GRB161219B - Anticipated hyperluminal evidence
- GRB 161224A: TSHAO optical observations
- GRB 161224A: Swift/UVOT Upper limits
- GRB 161224A: Swift-XRT refined Analysis
- GRB 161224A: Swift-BAT refined analysis
- Trigger 728094, Swift-BAT refined analysis
- GRB 161219B: UKIRT near-IR afterglow detection
- GRB161219.78 MASTER-Net OT detection
- GRB 161219B: Rapid ALMA Observations & Detection
- GRB 161220A: Swift-BAT refined analysis
- Konus-Wind observation of GRB 161219B
- GRB 161219B: SALT observations
- GRB 161214B: optical spectroscopy of the foreground SDSS object
- GRB 161220A: Swift-XRT refined Analysis
- GRB 161220A: GROND Upper Limits
- GRB 161219B: ISON/Terskol optical observations
- GRB 161219B: Swift-BAT refined analysis
- GRB 161220A: Swift/UVOT Upper Limits
- GRB 161219B: Swift/UVOT Detection
- GRB 161219B: Watcher optical observations
- IPN Triangulation of GRB 161218B (long/very bright)
- GRB 161220A: Swift detection of a burst
- GRB 161219B: LCO Sutherland observations
- GRB 161219B: GROND afterglow observations
- GRB 161219B: Swift-XRT refined Analysis
- GRB 161219B: Enhanced Swift-XRT position
- GRB 161219B: Swift detection of a burst with an optical afterglow
- GRB 161219A: a long GRB detected by INTEGRAL
- GRB 161218A: Swift-BAT refined analysis
- Swift Trigger 727422 is not an astrophysical event.
- GRB 161218A: TAROT Calern observatory optical observations
- GRB 161217A: TAROT Calern observatory optical observations
- GRB 161218B: Fermi GBM detection
- GRB 161217A: MITSuME Okayama upper limits
- GRB 161217A: Swift-BAT refined analysis
- GRB 161218A: Swift detection of a burst
- GRB 161217A: Swift/UVOT Upper Limits
- GRB 161217A: Swift-XRT refined Analysis
- GRB 161214B: AbAO and ISON/Terskol optical observations
- GRB 161217A: Enhanced Swift-XRT position
- GRB 161217A: Swift detection of a burst
- GRB 161214B: Mondy optical observations
- GRB 161214B: Swift-BAT refined analysis
- Fermi-LAT Gamma-ray Observations of IceCube-161210
- GRB 161214B: Swift/UVOT Afterglow Confirmation