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"7447 results found.
- LIGO/Virgo S190706ai: Updated sky localization
- LIGO/Virgo S190707q: Updated sky localization
- GRB 190708B: Tiled Swift observations
- LIGO/Virgo S190706ai: No transient candidates from CALET observations
- LIGO/Virgo S190707q: Upper limits from Fermi-GBM Observations
- LIGO/Virgo S190707q: Upper limits from AGILE-GRID observations
- LIGO/Virgo S190707q: No counterpart candidates in HAWC observations
- LIGO/Virgo S190706ai: Upper limits from Fermi-GBM Observations
- LIGO/Virgo S190707q : No neutrino counterpart candidates in ANTARES search
- LIGO/Virgo S190707q: Identification of a GW compact binary merger candidate
- LIGO/Virgo S190707q: Upper limits from IceCube neutrino searches
- LIGO/Virgo S190706ai: No neutrino counterpart candidates in ANTARES search
- LIGO/Virgo S190706ai: No counterpart candidates in HAWC observations
- LIGO/Virgo S190706ai: Identification of a GW compact binary merger candidate
- LIGO/Virgo S190706ai: Upper limits from IceCube neutrino searches
- GRB 190706B: Swift detection of a burst
- Fermi-LAT Gamma-ray Observations of IceCube-190704A and detection of the new gamma-ray source 1WHSP J104516.2+275133
- LIGO/Virgo S190701ah: Updated sky localization
- IceCube-190704A: not observable by Fermi-GBM
- IceCube-190704A - IceCube observation of a high-energy neutrino candidate event
- LIGO/Virgo S190630ag: Gaia Photometric Alerts transient candidate
- LIGO/Virgo S190630ag: no counterpart candidate in the SVOM/GWAC observations
- LIGO/Virgo S190701ah: KMTNet Observation
- IPN triangulation of GRB 190630A (short)
- LIGO/Virgo S190701ah: Upper limits from Fermi-GBM Observations
- LIGO/Virgo S190630ag: Upper limits from CALET observations
- LIGO/Virgo S190701ah: No neutrino counterpart candidates in ANTARES search
- LIGO/Virgo S190701ah: Identification of a GW compact binary merger candidate
- LIGO/Virgo S190701ah: Upper limits from IceCube neutrino searches
- GRB 190630C: KAIT Optical Upper Limit
- LIGO/Virgo S190630ag: No counterpart candidates in AGILE-GRID observations
- GRB 190701A: Swift detection of a burst
- GRB 190630B: KAIT Optical Afterglow Confirmation
- LIGO/Virgo S190630ag: Upper limits from Fermi-GBM Observations
- GRB 190630C: Swift detection of a burst
- LIGO/Virgo S190630ag: No neutrino counterpart candidates in ANTARES search
- LIGO/Virgo S190630ag: No counterpart candidates in HAWC observations
- LIGO/Virgo S190630ag: Identification of a GW compact binary merger candidate
- LIGO/Virgo S190630ag: Upper limits from IceCube neutrino searches
- IceCube-190629A: Upper limits from Fermi-GBM Observations
- GRB Swift Trigger 912102: KAIT Optical Afterglow Candidate
- Swift Trigger 912102: possible GRB 190630B
- IceCube-190629A - IceCube observation of a high-energy neutrino candidate event
- IceCube-190619A: prompt emission upper limits from AstroSat-CZTI
- IceCube-190619A: No counterpart candidates in ANTARES data
- LIGO/Virgo S190426c: Swift UVOT - no new counterpart candidates identified
- LIGO/Virgo S190510g: Swift UVOT - no new counterpart candidates identified
- IceCube-190619A - IceCube observation of a high-energy neutrino candidate event
- GRB 190610A: Swift/UVOT Upper Limits
- GRB 190610A: Swift-XRT observations
- GRB 190610A: Swift ToO observations
- 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 detection of a burst
- LIGO/Virgo S190425z: Swift UVOT - no new sources identified, and a summary of the Swift UVOT processing of GW triggers.
- LIGO/Virgo S190521r: Gaia Photometric Alerts transient candidate
- GRB 190604B: Swift detection of a burst
- LIGO/Virgo S190602aq: AstroSat CZTI upper limits
- LIGO/Virgo S190602aq: upper limit in INTEGRAL SPI-ACS prompt observations
- LIGO/Virgo S190602aq: Upper limits from Fermi-GBM Observations
- LIGO/Virgo S190602aq: No counterpart candidate in AGILE-MCAL observations
- LIGO/Virgo S190602aq: No neutrino counterpart candidates in ANTARES search
- LIGO/Virgo S190602aq: No counterpart candidates in HAWC observations
- LIGO/Virgo S190602aq: Identification of a GW compact binary merger candidate
- LIGO/Virgo S190602aq: Upper limits from IceCube neutrino searches
- GRB 190531B: Swift ToO observations
- GRB 190530A: Swift-XRT afterglow detection
- LIGO/Virgo S190503bf: Gaia Photometric Alerts transient candidate
- GRB 190530A: Swift ToO observations
- LIGO/Virgo S190425z: No counterpart candidate in Zadko-GRANDMA observations.
- LIGO/Virgo S190521r : Gaia Photometric Alerts transient candidate
- LIGO/Virgo S190518bb: AstroSat CZTI upper limits
- LIGO/Virgo S190521g: AstroSat CZTI upper limits
- LIGO/Virgo S190517h: AstroSat CZTI upper limits
- LIGO/Virgo S190519bj: AstroSat CZTI upper limits
- LIGO/Virgo S190521r: No optical counterpart from SVOM/GWAC-F30 observations.
- LIGO/Virgo S190521g: No optical counterpart from SVOM/GWAC-F30 observations.
- LIGO/Virgo S190524q: Retraction of GW compact binary merger candidate
- LIGO/Virgo S190517h: Gaia Photometric Alerts transient candidate
- LIGO/Virgo S190521r: No candidate counterparts from ATLAS observations of the skymap
- LIGO/Virgo S190521r: No transient candidates from CALET observations
- LIGO/Virgo S190521g: Upper limits from CALET observations
- LIGO/Virgo S190521r: Upper limits from Fermi-GBM observations
- LIGO/Virgo S190521g : Upper limits from Fermi-GBM observations
- LIGO/Virgo S190521g: Updated sky localization
- LIGO/Virgo S190521g: No candidate counterpart in Fermi-LAT observations
- LIGO/Virgo S190521r: No counterpart candidate in AGILE-MCAL observations
- LIGO/Virgo S190521r: No neutrino counterpart candidates in ANTARES search
- LIGO/Virgo S190521r: Identification of a GW compact binary merger candidate
- LIGO/Virgo S190517h : No counterpart candidate in TAROT-GRANDMA observations.
- LIGO/Virgo S190521r: No counterpart candidates in HAWC observations
- LIGO/Virgo S190521g: No neutrino counterpart candidates in ANTARES search
- LIGO/Virgo S190521g: No counterpart candidates in HAWC observations
- LIGO/Virgo S190521g: Identification of a GW compact binary merger candidate
- LIGO/Virgo S190519bj: Fermi GBM Observations
- LIGO/Virgo S190519bj: ANTARES neutrino search
- LIGO/Virgo S190519bj: HAWC follow-up
- LIGO/Virgo S190519bj: Identification of a GW compact binary merger candidate
- GRB 190519A: Swift detection of a burst
- LIGO/Virgo S190518bb: Retraction of GW compact binary merger candidate