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"5814 results found.
- IceCube Alert 190712.05 Global MASTER-Net observations report
- LIGO/Virgo S190707q: Upper limits from CALET observations
- LIGO/Virgo S190707q: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S190707q: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observations
- LIGO/Virgo S190706ai: No counterpart candidates in KAIT observations
- IPN triangulation of GRB 190704A (short)
- LIGO/Virgo S190706ai: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S190701ah: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S190707q: Upper limits from AGILE-GRID observations
- LIGO/Virgo S190707q: No counterpart candidates in AGILE-MCAL observations
- LIGO/Virgo S190707q: Coverage and upper limits from MAXI/GSC 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: Identification of a GW compact binary merger candidate
- GRB 190706B: Prompt enhanced Swift-XRT position
- IceCube Alert 190704.78 Global MASTER-Net observations report
- Baksan Neutrino Observatory Alert 190703.56 Global MASTER-Net observations report
- 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 Global MASTER-Net observations report
- GRB 190701A: COATLI Optical Observations
- GRB 190701A: MAXI/GSC detection
- GRB 190701A: Swift detection of a burst
- GRB 190630C: Swift detection of a burst
- LIGO/Virgo S190630ag Global MASTER-Net observations report
- Fermi trigger No 583567803 Global MASTER-Net observations report
- GRB 190630A: Fermi GBM Final Real-time Localization
- Fermi trigger No 583327924 Global MASTER-Net observations report
- Fermi trigger No 583111521 Global MASTER-Net observations report
- Swift GRB190624.86 Global MASTER-Net observations report
- Fermi-LAT Gamma-ray Observations of IceCube-190619A
- GRB 190613B: GROND Detection of the Optical/NIR Afterglow
- Fermi trigger No 582115625 Global MASTER-Net observations report
- GRB 190613B: Swift detection of a burst with an optical counterpart
- GRB 190613A: MASTER OT detection
- Swift GRB190613.17 Global MASTER-Net observations report
- GRB 190613A: Swift detection of a burst with an optical counterpart
- Fermi trigger No 582091643 Global MASTER-Net observations report
- Fermi trigger No 581889628 Global MASTER-Net observations report
- Fermi trigger No 581882394 Global MASTER-Net observations report
- GRB190609A: BALROG localization (Fermi Trigger 581758450 / GRB 190609315)
- IPN Triangulation of GRB 190606A (short)
- Fermi trigger No 581469752 Global MASTER-Net observations report
- LIGO/Virgo S190602aq Global MASTER-Net observations report
- LIGO/Virgo S190602aq: Identification of a GW compact binary merger candidate
- GRB 190530A: optical afterglow detection by 5 MASTER telescopes
- 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 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 Global MASTER-Net observations report
- LIGO/Virgo S190521r: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190519bj: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo S190521g: Identification of a GW compact binary merger candidate
- LIGO/Virgo S190521g Global MASTER-Net observations report
- LIGO/Virgo S190512at: SVOM/GWAC-F60A observations
- LIGO/Virgo S190519bj Global MASTER-Net observations report
- LIGO/Virgo S190519bj: Identification of a GW compact binary merger candidate
- LIGO/Virgo S190517h: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo S190517h: Fermi GBM Observations
- LIGO/Virgo S190517h Global MASTER-Net observations report
- LIGO/Virgo S190517h: Identification of a GW compact binary merger candidate
- LIGO/Virgo S190513bm: Swope follow-up observations
- LIGO/Virgo S190513bm : TAROT-Calern and TAROT-Chile (TCA/TCH)/GRANDMA observation report.
- Fermi GRB190514.67 Global MASTER-Net observations report
- LIGO/Virgo S190513bm: Lick/KAIT Follow-Up Observations
- LIGO/Virgo S190513bm Global MASTER-Net observations report
- LIGO/Virgo S190510g: Pan-STARRS and ATLAS observations and candidates
- LIGO/Virgo S190512at Global MASTER-Net observations report
- LIGO/Virgo S190512at: Identification of a GW compact binary merger candidate
- GRB 190512A: Swift detection of a burst
- LIGO/Virgo S190510g: GRAWITA REM and Loiano optical observations
- LIGO/Virgo S190510g: Unconfirmed OT in PGC 094244
- LIGO/Virgo S190510g: Dabancheng/HMT Follow-Up Observations
- LIGO/Virgo S190510g: Xinglong/Schmidt Follow-Up Observations
- LIGO/Virgo S190510g: SOAR/Goodman follow-up observations
- LIGO/Virgo S190510g: Lick/KAIT Follow-Up Observations
- LIGO/Virgo S190510g: Lulin Optical Follow-up Observations
- LIGO-Virgo S190426c: Pan-STARRS non-detection of ZTF19aassfws
- LIGO/Virgo S190510g: GRAWITA REM optical observations
- Fermi GRB190510.12 Global MASTER-Net observations report
- Fermi GRB190507.27 Global MASTER-Net observations report
- IceCube-190504A: MASTER optical monitoring analysis
- Fermi GRB190506.58 Global MASTER-Net observations report
- IceCube-190504A: Swift-XRT Follow-up Observations
- IceCube-190503A: Swift-XRT Follow-up Observations
- Fermi GRB190505.05 Global MASTER-Net observations report
- Fermi GRB190504.68 Global MASTER-Net observations report
- LIGO/Virgo S190503bf Global MASTER-Net observations report
- IceCube-190503A: Lick/KAIT Follow-Up Observations
- LIGO/Virgo S190503bf: MAXI/GSC Observations
- LIGO/Virgo S190503bf: Identification of a GW compact binary merger candidate
- LIGO/Virgo S190412m: Further J-GEM optical/NIR observations
- LIGO/Virgo S190426c: PS1 historical detections and ZTF photometry of Gaia19boq AT2019egk
- Fermi GRB190429.74 Global MASTER-Net observations report
- LIGO/Virgo S190426c: YAHPT Optical Observation
- LIGO/Virgo S190425z: MASTER detection of the faint flare in SDSS Seyfert galaxy z = 0.09