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"
24770 results found.
- GRB 170607A: Swift/UVOT Detection
- GRB 170607A: Fermi GBM observation
- GRB 170607A: NOT optical afterglow detection
- GRB 170607A: Swift-XRT refined Analysis
- GRB 170607A: Enhanced Swift-XRT position
- GRB 170607A: Swift detection of a burst with a bright optical counterpart
- GRB 170531B: Zeiss-1000/CrAO optical observations
- GRB 170531B: WHT spectroscopy
- GRB 170519A: TShAO and AbAO optical observations
- GRB 170604A: Swift/UVOT Observations
- GRB 170519A: Mondy optical observations
- GRB 170604A: RATIR Optical and NIR Observations
- GRB 170604A: AbAO optical observations
- Swift trigger 755873: Swift BAT and XRT refined analysis
- GRB 170522A: confirmation of the X-ray afterglow
- GROND observations of GRB170604A
- GRB 170604A: Swift-XRT refined Analysis
- GRB 170604A: GTC spectroscopic redshift
- GRB 170604A: Enhanced Swift-XRT position
- GRB 170604A: Swift-BAT refined analysis
- Swift Trigger 755873: a possible GRB
- GRB 170604A: optical observations
- GRB 170604A: Swift detection of a burst
- GRB 170531B: ISON/Terskol optical observations
- GRB 170531B: Swift/UVOT Detection
- GRB 170531B: SMARTS optical/IR observations
- GRB 170531B: Swift-BAT refined analysis
- GRB 170531A: Swift/UVOT Upper Limits
- GRB 170531B: LCO observations
- GRB 170531B: Swift-XRT refined Analysis
- GRB 170531A: Swift-XRT refined Analysis
- GROND observations of GRB 170531B
- GRB 170531B: Redshift from GTC/OSIRIS
- GRB 170531B: Enhanced Swift-XRT position
- GRB 170531B: CrAO confirmation of the afterglow
- GRB 170531B: Swift detection of a burst
- GRB 170531A: Swift detection of a burst
- GRB 170519A: CrAO optical observations
- GRB 170524B: Swift-UVOT/XRT Confirmation of Afterglow
- IPN Triangulation of GRB 170529A (long)
- GRB 170519A: ISON/Multa optical observations
- GRB 170511A: Fermi GBM observation
- LIGO/Virgo G268556: optical observations and classification of Pan-STARRS1 transients
- LIGO/Virgo G268556/GW170104: Konus-Wind observations
- GRB 170527A: Fermi GBM detection
- GRB 170526A, Swift-BAT refined analysis
- GRB 170526A: Swift/UVOT Upper Limits
- GRB 170526A: Swift-XRT refined Analysis
- LIGO/Virgo G268556: VERITAS Very-High-Energy Gamma-Ray Observations
- GRB 170524A: RATIR Optical and NIR Observations
- GRB 170526A: Enhanced Swift-XRT position
- GRB 170524B: Swift-XRT observations
- GRB 170526A: Swift detection of a burst
- GRB 170524A: TSHAO and CrAO optical observations
- GRB 170524A: Swift-BAT refined analysis
- GRB 170524B: Swift detection of a burst
- GRB 170524A: Swift/UVOT Upper Limits
- IPN Triangulation of GRB 170522A
- GRB 170524A: Enhanced Swift-XRT position
- GRB 170524A: Swift detection of a burst (or possible new SGR)
- GRB 170522A: LCO McDonald observations
- GRB 170522A: Swift-XRT observations
- GRB 170522A: Global MASTER-Net job
- GRB 170522A: Fermi GBM detection
- GRB 170514A CALET Gamma-Ray Burst Monitor detection
- GRB 170519A: Watcher optical observations
- GRB 170519A: Continued RATIR Optical and NIR Observations
- GRB 170519A: MITSuME Okayama Optical Observation
- GRB 170519A: NOT optical observations
- GRB170519A, Swift-UVOT Detection
- GRB 170519A: KAIT Optical Observations
- GRB 170519A: Swift-XRT refined Analysis
- GRB 170519A: Swift-BAT refined analysis
- GRB 170519A: Weihai optical observations
- GRB 170510A: LCO Siding Springs early observations
- GRB 170519A: RATIR Optical and NIR Observations
- GRB 170519A: optical observations
- GRB 170519A: Enhanced Swift-XRT position
- GRB 170519A: Swift detection of a burst with an optical counterpart
- LIGO/Virgo G277583: UH88/SNIFS classification of ATLAS and PS1 transients
- GRB 170510A: Swift-XRT afterglow detection
- GRB 170516A: Swift-BAT refined analysis
- GRB 170516A: Swift-XRT refined Analysis
- GRB 170516A: Swift/UVOT Upper Limits
- GRB 170516A: Enhanced Swift-XRT position
- GRB 170516A: Swift detection of a burst
- Swift Trigger AXP CXOU J164710.2-455216: MASTER-OAFA observations
- Swift Trigger on AXP CXOU J164710.2-455216
- GRB 170514A: Fermi GBM detection
- GRB 170510A: Global MASTER Net possible OT observations
- LIGO/Virgo G284239: Konus-Wind observations
- GRB 170510A: LCO possible counterpart
- GRB 170510A: Swift-XRT observations
- GRB 170510A: Fermi GBM observation
- LIGO/Virgo G284239: H.E.S.S. very-high energy gamma-ray follow-up
- LIGO/Virgo G284239: MAXI/GSC observations
- Swift Trigger 752193 is not a GRB
- LIGO/Virgo G284239: AstroSat CZTI upper limits
- GRB 170423A: TAROT Reunion observatory optical observations
- Swift XRT observations of GRB 170424A