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"19548 results found.
- GRB 190613B: Enhanced Swift-XRT position
- IPN Triangulation of GRB 190611B
- GRB 190613A: Enhanced Swift-XRT position
- GRB 190613B: Swift detection of a burst with an optical counterpart
- GRB 190613A: Swift detection of a burst with an optical counterpart
- GRB 190611A: Swift/UVOT Upper Limits
- GRB 190611A: Optical observations from VLT/FORS2
- GRB 190611A: Enhanced Swift-XRT position
- GRB 190611A: Swift detection of a burst
- GRB 190608A: Fermi GBM Final Real-time Localization
- LIGO/Virgo S190425z: Swift UVOT - no new sources identified, and a summary of the Swift UVOT processing of GW triggers.
- GRB 190604B: VLT Afterglow Detection
- GRB 190604B: Kitab observatory optical upper limit
- GRB190604B: GROWTH-India telescope followup - no optical counterpart found
- GRB190604B: Swift/UVOT detection
- GRB 190604B: Enhanced Swift-XRT position
- GRB190530A: Photometric follow-up with GROWTH-India telescope
- GRB 190604B: Swift detection of a burst
- LIGO/Virgo S190602aq: Upper limits from CALET observations
- GRB 190531B: Swift/UVOT Upper Limits
- GRB 190530A: R-band observation from HCT
- LIGO/Virgo S190602aq: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
- LIGO/Virgo S190602aq: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S190602aq: No counterpart candidates in the Swift/BAT Observations
- LIGO/Virgo S190602aq: No neutrino counterpart candidates in ANTARES search
- LIGO/Virgo S190602aq: No counterpart candidates in HAWC observations
- GRB 190531B: VLT optical upper limit
- GRB 190530A: SAO RAS optical observations
- GRB 190531B: Swift-XRT afterglow detection
- GRB 190530A: Swift/UVOT Detection
- GRB 190531B: Swift ToO observations
- GRB 190530A: COATLI Optical Detection of the Fading Afterglow
- GRB 190530A: Swift-XRT afterglow detection
- GRB 190530A: GWAC-F30 optical detection
- GRB 190530A: OAJ optical detection
- GRB 190530A: NOT photometry and spectroscopy
- GRB 190530A: Swift ToO observations
- GRB 190530A: AGILE-MCAL detection
- LIGO/Virgo S190521r: CNEOST follow-up observations
- LIGO/Virgo S190521r: Kanata optical/NIR follow-up observations of the CNEOST Transient
- LIGO/Virgo S190521r: No optical counterpart from SVOM/GWAC-F30 observations.
- LIGO/Virgo S190521r: No optical counterpart from SVOM/GWAC observations.
- LIGO/Virgo S190521g: No optical counterpart from SVOM/GWAC observations.
- LIGO/Virgo S190521r: RATIR Optical and NIR Observations of the CNEOST Transient
- LIGO/Virgo S190521g: Upper limits from CALET observations
- LIGO/Virgo S190521g: Swift/BAT Counterpart Search
- LIGO/Virgo S190521r: Swift/BAT Counterpart Search
- LIGO/Virgo S190521g: No Counterparts in DDOTI/OAN Optical Observations
- LIGO/Virgo S190521r: Coverage and upper limits from Fermi-LAT observations
- LIGO/Virgo S190521g: No candidate counterpart in Fermi-LAT observations
- LIGO/Virgo S190521r: No neutrino counterpart candidates in ANTARES search
- LIGO/Virgo S190521r: No counterpart candidates in HAWC observations
- LIGO/Virgo S190521r: No counterpart candidates in INTEGRAL SPI/ACS prompt observation
- LIGO/Virgo S190521g: No neutrino counterpart candidates in ANTARES search
- LIGO/Virgo S190519bj: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo S190521g: No counterpart candidates in INTEGRAL SPI/ACS & IBIS/PICsIT prompt observations
- LIGO/Virgo S190521g: No counterpart candidates in HAWC observations
- LIGO/Virgo S190521g: Identification of a GW compact binary merger candidate
- LIGO/Virgo S190521g: INTEGRAL SPI/ACS prompt observation
- S190519bj: No transient candidates from CALET observations
- LIGO/Virgo S190512at: SVOM/GWAC-F60A observations
- GRB 190519A: Swift/UVOT Upper Limits
- LIGO/Virgo S190519bj: Swift/BAT Counterpart Search
- GRB 190519A: Swift-BAT refined analysis
- LIGO/Virgo S190519bj: ANTARES neutrino search
- LIGO/Virgo S190519bj: HAWC follow-up
- LIGO/Virgo S190519bj: INTEGRAL SPI/ACS prompt observation
- GRB 190519A: Enhanced Swift-XRT position
- GRB 190519A: Swift detection of a burst
- LIGO/Virgo S190517h: CALET Observations
- LIGO/Virgo S190517h: INTEGRAL prompt observation
- LIGO/Virgo S190517h: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo S190517h: Swift/BAT Counterpart Search
- LIGO/Virgo S190517h: ANTARES neutrino search
- LIGO/Virgo S190517h: HAWC follow-up
- LIGO/Virgo S190517h: INTEGRAL/SPI-ACS prompt observation
- GRB 190515B: Swift/UVOT Upper Limits
- GRB 190515B: Optical observations from OSN
- GRB 190515B: Enhanced Swift-XRT position
- GRB 190515B: Kitab Observatory optical upper limit
- GRB 190515B: Swift detection of a burst
- LIGO/Virgo S190513bm: CALET Observations
- LIGO/Virgo S190513bm: Swift/BAT Counterpart Search
- LIGO/Virgo S190513bm: ANTARES neutrino search
- LIGO/Virgo S190513bm: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo S190512at: CALET Observations
- LIGO/Virgo S190513bm: MAXI/GSC Observations
- LIGO/Virgo S190513bm: INTEGRAL prompt observation
- LIGO/Virgo S190513bm: HAWC follow-up
- LIGO-Virgo S190512at: AGILE GRID observations
- LIGO/Virgo S190512at: Swift/BAT Counterpart Search
- LIGO/Virgo S190510g: Pan-STARRS and ATLAS observations and candidates
- LIGO/Virgo S190512at: ANTARES neutrino search
- LIGO/Virgo S190512at: Fermi-LAT search for a high-energy gamma-ray counterpart
- IPN triangulation of GRB 190510A (short)
- LIGO/Virgo S190510g: DOAO Observation
- LIGO/Virgo S190510g: CALET Observations
- GRB 190511A: Swift/UVOT Detection
- GRB 190511A: NOT optical afterglow
- LIGO/Virgo S190426c: VLA Follow-Up Observations of ZTF19aassfws