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"26364 results found.
- LIGO/Virgo S190602aq: Upper limits from Fermi-GBM Observations
- LIGO/Virgo S190602aq: Upper limits from AGILE-GRID observations
- LIGO/Virgo S190602aq: No counterpart candidate in AGILE-MCAL observations
- LIGO/Virgo S190602aq: Coverage and upper limits from MAXI/GSC 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
- Konus-Wind observation of extremely bright GRB 190530A
- GRB 190530A: Insight-HXMT/HE detection
- GRB 190531B: Insight-HXMT/HE detection
- GRB 190531B: VLT optical upper limit
- GRB 190530A: SAO RAS optical observations
- GRB 190531B: Swift-XRT afterglow detection
- GRB 190531B: Fermi GBM observations
- GRB 190530A: Swift/UVOT Detection
- GRB 190530A: Steep afterglow decay found by OSN
- Fermi Trigger 581026217 / GRB 190531840 / GRB190531A: BALROG localization
- GRB 190530A: Fermi GBM observation
- 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
- Fermi GRB190530.43 Global MASTER-Net observations report
- GRB 190530A: Bright afterglow confirmed by OSN
- GRB 190530A: AGILE/GRID analysis
- Fermi Trigger 580904353 / GRB 190530430 / GRB190530A: BALROG localization
- LIGO/Virgo S190521r: CNEOST follow-up observations
- GRB 190525A: Insight-HXMT/HE detection
- 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-F30 observations.
- LIGO/Virgo S190521g: No optical counterpart from SVOM/GWAC observations.
- Konus-Wind observation of GRB 190519A
- LIGO/Virgo S190521g: Upper limits from Insight-HXMT/HE observations
- LIGO/Virgo S190521r: RATIR Optical and NIR Observations of the CNEOST Transient
- 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 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: Upper limits from AGILE-GRID observations
- LIGO/Virgo S190521r: No counterpart candidate in AGILE-MCAL observations
- LIGO/Virgo S190521r: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190521r: No neutrino counterpart candidates in ANTARES search
- LIGO/Virgo S190521r: IceCube Neutrino Search
- LIGO/Virgo S190521r: Identification of a GW compact binary merger candidate
- 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: Upper Limits from AGILE-GRID observations
- IGO/Virgo S190521g: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190521g: No counterpart candidates in INTEGRAL SPI/ACS & IBIS/PICsIT prompt observations
- LIGO/Virgo S190521g: No counterpart candidates in AGILE-MCAL 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
- LIGO/Virgo S190521g: IceCube Neutrino Search
- S190519bj: No transient candidates from CALET observations
- LIGO/Virgo S190519bj: Upper limits from Insight-HXMT/HE observations
- LIGO/Virgo S190512at: SVOM/GWAC-F60A observations
- GRB 190519A: Swift/UVOT Upper Limits
- LIGO/Virgo S190519bj: Swift/BAT Counterpart Search
- LIGO/Virgo S190519bj: MAXI/GSC Observations
- GRB 190519A: Swift-XRT refined Analysis
- GRB 190519A: Swift-BAT refined analysis
- LIGO/Virgo S190519bj: Fermi GBM Observations
- LIGO-Virgo S190519bj: AGILE GRID observations
- LIGO/Virgo S190519bj: AGILE MCAL observations
- LIGO/Virgo S190519bj: ANTARES neutrino search
- LIGO/Virgo S190519bj: HAWC follow-up
- LIGO/Virgo S190519bj: INTEGRAL SPI/ACS prompt observation
- LIGO/Virgo S190519bj: IceCube Neutrino Search
- LIGO/Virgo S190519bj: Identification of a GW compact binary merger candidate
- GRB 190519A: Enhanced Swift-XRT position
- GRB 190519A: Swift detection of a burst
- LIGO/Virgo S190517h: INTEGRAL prompt observation
- Fermi GRB190517.81 Global MASTER-Net observations report
- Fermi Trigger 579814215 / GRB 190517813 / GRB190517A: BALROG localization
- LIGO/Virgo S190512at: Updated sky localization
- 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: Insight-HXMT/HE observations
- LIGO/Virgo S190517h: Fermi GBM Observations
- LIGO/Virgo S190517h: HAWC follow-up
- LIGO/Virgo S190517h: MAXI/GSC Observations
- LIGO-Virgo S190517h: AGILE GRID observations
- LIGO/Virgo S190517h: AGILE MCAL observations
- LIGO/Virgo S190517h: INTEGRAL/SPI-ACS prompt observation
- LIGO/Virgo S190517h: Identification of a GW compact binary merger candidate
- GRB 190515B: Swift/UVOT Upper Limits
- Fermi GRB190515.49 Global MASTER-Net observations report
- GRB 190515B: Swift-BAT refined analysis