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.
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subject:"Swift"body:"GRB"submitter:"Judith Racusin"- 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
- GRB 170516A: Swift-BAT refined analysis
- GRB 170516A: Swift-XRT refined Analysis
- 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 AXP CXOU J164710.2-455216: MASTER-OAFA observations
- Swift Trigger on AXP CXOU J164710.2-455216
- GRB 170514A: Fermi GBM detection
- GRB 170510A: AstroSat CZTI(Veto) detection
- Fermi GBM trigger 516459580/170514541 is not a GRB
- GRB 170510A: Global MASTER Net possible OT observations
- Konus-Wind observation of GRB 170510A
- LIGO/Virgo G275404 and G275659: SkyMapper Follow-up 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
- GRB 170510A: Tiled Swift observations
- GRB 170510A: Fermi-LAT detection
- Swift Trigger 752193 is not a GRB
- LIGO/Virgo G284239: AstroSat CZTI upper limits
- Trigger 751928: Swift misidentification of Cen X-3
- GRB 170423A: TAROT Reunion observatory optical observations
- IceCube-170506A - IceCube update on a high-energy neutrino candidate event
- Swift XRT observations of GRB 170424A
- LIGO/Virgo G284239:SVOM/Mini-GWAC observations of the initial skymap
- LIGO/VIRGO G284239: Fermi GBM Upper Limits
- 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
- GRB 170428A CALET Gamma-Ray Burst Monitor detection
- LIGO/Virgo: G284239 ANTARES search
- LIGO/Virgo G284239: Swift/BAT data search
- LIGO/Virgo G284239: AGILE GRID observations
- LIGO/Virgo G284239: INTEGRAL search for a prompt gamma-ray counterpart
- LIGO/Virgo G284239: AGILE MCAL Observations
- LIGO/Virgo G284239: IceCube neutrino observations
- LIGO/Virgo G284239: Identification of a GW Burst Candidate
- GRB 170428A: GTC spectroscopic redshift of candidate host galaxy
- GRB 170428A: 15 GHz upper limits from AMI
- Swift Trigger 748858: 15 GHz upper limits from AMI
- LIGO/Virgo G268556: Refined localization from CBC parameter estimation
- GRB 170428A: TNG optical observations
- Short GRB 170428A: MASTER-OAFA final reduction of the optical observations
- GRB 170428A: DCT Imaging
- 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
- GRB 170428A: Swift-BAT refined analysis
- Konus-Wind observation of GRB 170428A
- GRB 170428A: MASTER-OAFA early optical observations
- Swift Trigger 750337 is probably a noise fluctuation
- GRB 170428A: Swift detection of a short burst
- Swift trigger 750096 - OT candidate
- GRB170426.95 MASTER-Net OT detection
- Swift Trigger 750096 is probably a noise fluctuation
- Swift Trigger 750044 is probably a noise fluctuation
- GRB 170424A: LCO Observations
- Konus-Wind observation of GRB 170424A
- GRB 170419A: Swift/UVOT Upper Limits
- GRB 170424A: Tiled Swift observations
- GRB 170424A: Fermi GBM detection
- GRB 170424A: Fermi-LAT detection
- GRB 170419A: LCO Observations
- GRB 170423A: Fermi GBM detection
- Swift Trigger 748858: AbAO and TSHAO optical observations
- Fermi GBM trigger 514436208/170421123 is not a GRB
- Swift Trigger 748858: TAROT La Silla observatory optical observations
- Swift Trigger 748858: RATIR Optical and NIR Observations
- GRB 170419B, Swift-BAT refined analysis
- GRB 170419B: Zadko observatory - Gingin optical observations
- GRB 170419A: Zadko observatory - Gingin optical observations
- Fermi GBM trigger 514379207/170420463 is not a GRB
- GRB 170419A: Swift-XRT refined Analysis
- GRB 170412A CALET Gamma-Ray Burst Monitor detection
- GRB 170419B: Fermi GBM observation
- GRB 170419A: Swift-BAT refined analysis
- Swift trigger 748858: Swift BAT, XRT, and UVOT refined analysis
- GRB 170419B: Swift detection of a burst
- GRB 170419A: Enhanced Swift-XRT position
- Swift Trigger 748858: MASTER-OAFA early optical observations
- GRB 170419A: Swift detection of a burst
- Swift Trigger 748858: Zadko observatory - Gingin optical observations
- Swift Trigger 748858: a possible GRB