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"
2723 results found.
- LIGO/Virgo S190923y: Upper limits from IceCube neutrino searches
- Fermi trigger No 590777160: Global MASTER-Net observations report
- Baksan Neutrino Observatory Alert 190920.65: Global MASTER-Net observations report
- GRB 190919B: FRAM-Auger optical detection
- GRB 190919B: Swift-XRT observations
- Integral GRB190919.99: Global MASTER-Net observations report
- LIGO/Virgo S190915ak: No significant candidates in TAROT-GRANDMA observations
- LIGO/Virgo S190910h: No significant candidates in TAROT-GRANDMA observations
- LIGO/Virgo S190915ak: no counterpart candidates in the Swift/BAT observations
- LIGO/Virgo S190910d : No significant candidates in TAROT-GRANDMA observations
- LIGO/Virgo S190814bv: No counterpart candidate after completion of GRAWITA VST-ESO PARANAL transient survey.
- LIGO/Virgo S190910d and S190910h: No counterpart candidates in KAIT observations
- LIGO/Virgo S190910h: Four additional candidates from the Zwicky Transient Facility
- Update to the Fermi GBM Localizations
- LIGO/Virgo S190910h: Candidates from the Zwicky Transient Facility
- LIGO/Virgo S190910h: no counterpart candidates in the Swift/BAT observations
- LIGO/Virgo S190910h: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- LIGO/Virgo S190910d: Candidates from the Zwicky Transient Facility
- LIGO/Virgo S190910d: no counterpart candidates in the Swift/BAT Observations
- LIGO/Virgo S190910d: Upper limits from Fermi-GBM Observations
- LIGO/Virgo S190814bv: VLA/JAGWAR monitoring of the 50% containment region
- GRB 190829A optical observation
- LIGO/Virgo S190901ap : No significant candidates in TAROT-GRANDMA
- LIGO/Virgo S190901ap: No counterpart candidates in KAIT observations
- LIGO/Virgo S190901ap: Additional candidates from the Zwicky Transient Facility
- LIGO/Virgo S190901ap: no counterpart candidate in the SVOM/GWAC observations
- LIGO/Virgo S190901ap: Additional observations from the Zwicky Transient Facility
- LIGO/Virgo S190828l: no counterpart candidate in the SVOM/GWAC observations
- LIGO/Virgo S190828j: no counterpart candidate in the SVOM/GWAC observations
- LIGO/Virgo S190901ap: no counterpart candidates in the Swift/BAT Observations
- LIGO/Virgo S190901ap: Candidates from the Zwicky Transient Facility
- LIGO/Virgo S190901ap: No counterpart candidates in INTEGRAL SPI-ACS,prompt observation
- LIGO/Virgo S190814bv : No significant candidates in TAROT-GRANDMA observations
- LIGO/Virgo S190828j : No significant candidates in TAROT-GRANDMA observations
- LIGO/Virgo S190828l: No significant candidates in TAROT-GRANDMA observations
- LIGO/Virgo S190828l: No counterpart candidates in KAIT observations
- LIGO/Virgo S190828j: No counterpart candidates in KAIT observations
- GRB 190828C: Fermi GBM Final Real-time Localization
- GRB 190828A: MAXI/GSC detection
- Fermi GBM-190816: Eight additional candidates from the Zwicky Transient Facility
- LIGO/Virgo S190814bv: Detection of a candidate radio counterpart with ASKAP
- LIGO/Virgo S190814bv: LCO Photometry of DG19wxnjc/AT2019npv
- LIGO/Virgo S190814bv: MASTER prediscovery and postdiscovery observations DECam candidate DG19wxnjc/AT2019npv field
- LIGO/Virgo S190814bv: No Optical Counterpart Candidates in Second-Epoch Lick/KAIT Observations
- Fermi GBM-190816: Four additional candidates from the Zwicky Transient Facility
- Fermi GBM-190816: One candidate counterpart from the Zwicky Transient Facility
- LIGO/Virgo GBM-190816: no counterpart candidates in the Swift/BAT Observations
- Fermi GBM-190816: Location-dependent upper limits from INTEGRAL/SPI-ACS prompt observation
- IceCube-190819A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- LIGO/Virgo S190814bv: GRAWITA TNG infrared imaging of desgw-190814e, DG19sevhc and selected galaxies
- LIGO/Virgo S190814bv : No Counterpart Candidates in Continued Galaxy Targeted Search with Magellan
- LIGO/Virgo S190814bv: No additional candidates from the Zwicky Transient Facility
- LIGO/Virgo S190814bv: no candidates from optical imaging of selected galaxies at the NOT
- LIGO/Virgo S190814bv : No Counterpart Candidates in Galaxy Targeted Search with Magellan
- Fermi trigger No 587505927 Global MASTER-Net observations report
- LIGO/Virgo S190814bv: No counterpart candidates in KAIT observations
- LIGO/Virgo S190814bv: no counterpart candidates in Swope imaging
- LIGO/Virgo S190814bv: no counterpart candidates in Keck I MOSFIRE imaging
- LIGO/Virgo S190814bv: No candidates from the Zwicky Transient Facility
- LIGO/Virgo S190814bv: No counterpart candidates in the Swift/BAT Observations
- LIGO/Virgo S190814bv: GRAWITA TNG imaging of selected galaxies
- LIGO/Virgo S190814bv: Liverpool Telescope imaging of selected galaxies
- LIGO/Virgo S190814bv: Nordic Optical Telescope imaging of selected galaxies
- LIGO/Virgo S190814bv: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- LIGO/Virgo S190814bv Global MASTER-Net observations report
- FRB 190806: MASTER optical observation
- Fermi trigger No 586676451 Global MASTER-Net observations report
- GRB 190804B: MAXI/GSC detection
- Fermi trigger No 586574612 Global MASTER-Net observations report
- LIGO/Virgo S190728q: No counterpart candidates in H.E.S.S. observations
- LIGO/Virgo S190727h: AstroSat CZTI upper limits
- LIGO/Virgo S190728q: MITSuME Okayama and Bisei Follow-Up of ZTF19abjethn (AT2019lvs)
- LIGO/Virgo S190728q: Optical transients from Pan-STARRS coverage during first 2 nights
- LIGO/Virgo s190728q: ePESSTO+ NTT classification of AT2019lvt as a type-Ia SN
- LIGO/Virgo S190728q: No counterpart candidates in KAIT observations
- LIGO/Virgo S190728q: Optical Candidate from the Zwicky Transient Facility ZTF19abjethn
- LIGO/Virgo S190727h: No counterpart candidates in KAIT observations
- Fermi trigger No 585621841 Global MASTER-Net observations report
- LIGO/Virgo S190720a: No counterpart candidates in KAIT observations
- GRB 190720A: Fermi GBM Final Real-time Localization
- LIGO/Virgo S190718y: No counterpart candidates in CNEOST
- LIGO/Virgo S190720a Global MASTER-Net observations report
- LIGO/Virgo S190718y: No counterpart candidates in KAIT observations
- LIGO/Virgo S190718y: Upper limits from Fermi-GBM Observations
- LIGO/Virgo S190718y: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- GRB 190613B: FRAM-Auger afterglow detection
- Fermi trigger No 584977168 Global MASTER-Net observations report
- Fermi trigger No 584929684 Global MASTER-Net observations report
- IceCube Alert 190712.05 Global MASTER-Net observations report
- Fermi trigger No 584583925 Global MASTER-Net observations report
- Fermi trigger No 584465880 Global MASTER-Net observations report
- Fermi trigger No 584404689 Global MASTER-Net observations report
- GRB 190708B: MAXI/GSC detection
- LIGO/Virgo S190706ai: No counterpart candidates in KAIT observations
- GRB 190706A: MAXI/GSC detection
- LIGO/Virgo S190630ag: no counterpart candidate in the SVOM/GWAC observations
- GRB 190701A: COATLI Optical Observations
- GRB 190701A: Swift detection of a burst
- GRB 190630B: Swift-XRT refined Analysis
- Fermi trigger No 583567803 Global MASTER-Net observations report