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.
Advanced Search Examples (click to copy):
subject:"Swift"body:"GRB"submitter:"Judith Racusin"19090 results found.
- 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
- GRB 170405A: SMARTS optical/IR afterglow observations
- GRB 170317A: SAO RAS optical observations
- GRB170405A, Swift-UVOT Detection
- GRB 170405A, Swift-BAT refined analysis
- GRB 170405A: Etelman observatory optical observations
- GRB 170405A: Swift-XRT refined Analysis
- GRB 170405A: RATIR Optical and NIR Observations
- Trigger 745966: Swift detection of 4U1850-03
- GRB 170405A: ISON/Terskol optical observations
- GRB 170405A: Watcher optical detection
- GRB 170405A: Redshift from OSIRIS/GTC
- GRB 170405A: TAROT Reunion observatory optical observations
- GRB 170405A: Enhanced Swift-XRT position
- GRB 170405A: Swift detection of a burst with an optical counterpart
- LIGO/Virgo G275404: European VLBI Network (EVN) follow-up of the near-IR transient in the AGL J1914+1043 field
- IPN Triangulation of GRB 170403A (short)
- Swift Trigger 745090 is a noise trigger near NGC 5195
- Fermi-LAT Gamma-ray Observations of IceCube-170321
- Swift triggered on SAX J1806.5-221
- GRB 170330A: Swift-BAT refined analysis
- DOAO 1m telescope V, R, I observation of GRB 170317A
- GRB 170331A: Swift/UVOT Upper Limits
- IceCube-170321A: Swift-XRT observations
- GRB 170330A: Enhanced Swift-XRT position
- GRB 170331A: Enhanced Swift-XRT position
- GRB 170330A: Swift/UVOT Detection of a Fading Afterglow
- LIGO/Virgo G275697: LOFAR follow-up
- GRB 170331A: Swift detection of a burst
- GRB 170330A: Swift detection of a burst
- GRB 170325A, Swift-BAT detection of a short GRB
- LIGO/Virgo G277583: INTEGRAL search for an X-ray and gamma-ray counterpart
- LIGO/Virgo G275697: AMI Large Array Search for a Radio Afterglow
- INTEGRAL SPI-ACS observation of AMON IceCube EHE 80305071 129307
- IPN Triangulation of GRB 170320A (long/intense)
- GRB 170317A: Mondy optical observations
- GRB 170318B: RATIR Optical and NIR Observations
- GRB 170317A: RATIR Optical and NIR Observations
- GRB 170318B: Swift/UVOT Upper Limits
- GRB 170318B: Swift-XRT refined Analysis
- GRB 170318A: Swift-XRT refined Analysis
- LIGO/Virgo G277583: CALET Observations
- GRB 170318A: RATIR Optical and NIR Observations
- GRB 170318A: Swift/UVOT Upper Limits
- GRB 170317A: RATIR Optical and NIR Observations
- GRB 170318B: Enhanced Swift-XRT position
- GRB 170318B: Swift detection of a burst
- GRB 170318A: Enhanced Swift-XRT position
- GRB 170318A: Swift detection of a burst
- GRB 170317A: MITSuME Okayama Optical Observation
- LIGO/Virgo G277583: AstroSat CZTI upper limits
- GRB 170317A: Swift/UVOT Detection
- GRB 170317A: Mondy optical observations
- GRB 170317A: MITSuME Okayama Ks-band upper-limit