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"19543 results found.
- GRB 170531B: LCO observations
- 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 170531A: Swift/UVOT Observations
- 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
- LIGO/Virgo G268556: optical observations and classification of Pan-STARRS1 transients
- GRB 170526A: Swift/UVOT Upper Limits
- LIGO/Virgo G268556: VERITAS Very-High-Energy Gamma-Ray Observations
- GRB 170524A: RATIR Optical and NIR Observations
- GRB 170526A: Enhanced Swift-XRT position
- GRB 170526A: Swift detection of a burst
- GRB 170524B: MASTER-OAFA observations
- GRB 170524A: TSHAO and CrAO optical observations
- GRB 170524B: Swift ToO observations
- GRB 170524A: Swift-BAT refined analysis
- 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: Global MASTER-Net job
- GRB 170522A: Tiled Swift observations
- GRB 170522A: Fermi-LAT detection
- GRB 170522A: Fermi GBM 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: 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
- GRB 170510A CALET Gamma-Ray Burst Monitor detection
- LIGO/Virgo G277583: UH88/SNIFS classification of ATLAS and PS1 transients
- GRB 170510A: Swift-XRT afterglow detection
- AXP CXOU J164710.2-455216: Fermi GBM observation
- GRB 170516A: Swift/UVOT Upper Limits
- GRB 170516A: Enhanced Swift-XRT position
- GRB 170516A: Swift detection of a burst
- Swift Trigger on AXP CXOU J164710.2-455216
- GRB 170510A: AstroSat CZTI(Veto) detection
- GRB 170510A: Global MASTER Net possible OT observations
- Konus-Wind observation of GRB 170510A
- 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
- GRB 170510A: Tiled Swift observations
- GRB 170510A: Fermi-LAT detection
- 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
- LIGO/Virgo G284239:SVOM/Mini-GWAC observations of the initial skymap
- LIGO/Virgo G284239: HAWC follow-up
- LIGO/Virgo G284239: MASTER automatic follow up and synchronous observations
- LIGO/Virgo G284239: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo G284239: TZAC TAROT network observations with TRE/TCA/TCH
- LIGO/Virgo: G284239 ANTARES search
- LIGO/Virgo G284239: Swift/BAT data search
- LIGO/Virgo G284239: INTEGRAL search for a prompt gamma-ray counterpart
- GRB 170428A: GTC spectroscopic redshift of candidate host galaxy
- GRB 170428A: TNG optical observations
- GRB 170428A: TAROT La Silla observatory optical observations
- GRB 170428A: RATIR Afterglow Confirmation
- GRB 170428A: GROND detection of the afterglow
- GRB 170428A: Swift/UVOT Upper Limits
- GRB 170428A: Xinglong 2.16-m upper limit and host galaxy candidate
- GRB 170428A: Swift-XRT refined Analysis
- Swift Trigger 750337 is probably a noise fluctuation
- GRB 170428A: Swift detection of a short burst
- Swift Trigger 750096 is probably a noise fluctuation
- Swift Trigger 750044 is probably a noise fluctuation
- GRB 170424A: LCO Observations
- GRB 170419A: Swift/UVOT Upper Limits
- GRB 170424A: Tiled Swift observations
- GRB 170419A: LCO Observations
- Swift Trigger 748858: AbAO and TSHAO optical observations
- Swift Trigger 748858: TAROT La Silla observatory optical observations
- Swift Trigger 748858: RATIR Optical and NIR Observations
- GRB 170419B: Zadko observatory - Gingin optical observations
- GRB 170419A: Zadko observatory - Gingin optical observations
- Swift trigger 748858: Swift BAT, XRT, and UVOT refined analysis
- GRB 170419A: Enhanced Swift-XRT position
- GRB 170419A: Swift detection of a burst
- Swift Trigger 748858: Zadko observatory - Gingin optical observations
- Swift Trigger 748858: a possible GRB
- LIGO/Virgo G275404: DLT40 follow-up observation
- GRB 170409A: TAROT Reunion observatory optical observations