GCN Circulars
GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"14932 results found.
- IceCube-190504A: MASTER optical monitoring analysis
- GRB 190507A: Fermi GBM Final Real-time Localization
- Update to the Fermi GBM GCN Reporting
- IceCube-190504A: Insight-HXMT/HE observation
- GRB 190501A: CALET Gamma-Ray Burst Monitor detection
- Search for counterpart to IceCube-190504A with ANTARES
- IceCube-190503A: Insight-HXMT/HE observation
- LIGO/Virgo S190503bf: Swift/BAT Counterpart Search
- LIGO/Virgo S190503bf: Insight-HXMT/HE observation
- IceCube-190503A: Insight-HXMT/HE observation
- LIGO/Virgo S190503bf: Fermi-GBM Observations
- Correction in name: GRB 190501B (not GRB 190501BA) : AstroSat CZTI detection
- GRB 190501B: AstroSat CZTI detection
- IPN Triangulation of GRB 190501A (long/bright)
- GRB 190501A: GOTO optical counterpart search
- LIGO/Virgo S190425z: Insight-HXMT observation and counterpart search
- LIGO/Virgo S190426c: Gaia19boq 0.6m BOOTES-5/JGT, 1.5m OSN and 10.4m GTC observations
- GRB 190501A: refined position from AGILE/GRID analysis
- GRB 190501A: AGILE/GRID detection
- GRB 190501A: AGILE/MCAL and scientific ratemeters detection of a burst
- LIGO/Virgo S190426c: ZTF19aaslzjf, ZTF19aasmftm and ZTF19aasmddt 1.5m OSN and 10.4m GTC observations
- GRB 190429A: AstroSat CZTI detection
- GRB 190427A: CALET Gamma-Ray Burst Monitor detection
- LIGO/Virgo S190425z: MASTER detection of the faint flare in SDSS Seyfert galaxy z = 0.09
- LIGO/Virgo S190425z: DECam Observations of the UVOT Candidate Region
- LIGO/Virgo S190425z: RATIR non-detection of the Swift/UVOT source
- LIGO/Virgo S190425z: VISTA K-band observations of the Swift/UVOT Transient
- LIGO/Virgo S190425z: MASTER explanation of the nature of an optical flash detected by a Swift as a short flare on a fast-moving WISE brown
- LIGO/Virgo S190425z: No i-band detection of the Swift/UVOT transient in SkyMapper observations
- LIGO/Virgo S190425z: 1.5m OSN and 10.4m imaging of the UVOT source field
- LIGO/Virgo S190425z: No source found at UVOT source location at 6 hrs after LVC report
- LIGO/Virgo S190426c: DG19ytre and DG19kplb 1.5m OSN imaging and 10.4m GTC spectroscopy
- LIGO/Virgo S190425z: No Optical Detection of the Swift/UVOT Transient in ASAS-SN observations hours before and after discovery
- LIGO/Virgo S190425z: No Optical Detection of the Swift/UVOT Transient with Las Cumbres Observatory
- LIGO/Virgo S190425z: Pre-discovery NIR limits of the UVOT transient candidate from Gattini-IR
- LIGO/Virgo S190425z: ZTF photometry of the UVOT transient candidate hours before discovery
- LIGO/Virgo S190426c: J-GEM optical/NIR follow-up observations
- GRB 190419A: AstroSat CZTI detection
- GRB 190427A: Fermi GBM detection
- LIGO/Virgo S190426c: Optical Wide-field Search with the Zwicky Transient Facility
- LIGO/Virgo S190426c: Insight-HXMT/HE observation
- GRB 190427A: BOOTES-1 and BOOTES-5/JGT early follow-up observations
- LIGO/Virgo S190425z: BOOTES-5/JGT observations of galaxies
- LIGO/Virgo S190425z - ePESSTO+ spectrum of candidate PS19qu
- GRB 190427A: Swift detection of a short burst
- LIGO/Virgo S190426c: a possible lensed NS-NS merger
- LIGO/Virgo S190426c: Fermi GBM Observations
- LIGO/Virgo S190426c: HAWC follow-up
- LIGO/Virgo S190425z: Keck NIR spectroscopy shows AT2019ebq is a supernova
- LIGO/Virgo S190425z: Nearby Galaxies in the Updated Localization Volume
- LIGO/Virgo S190425z: GROND observations of AT2019ebq/PS19qp
- LIGO/Virgo S190425z: AMI-LA radio observations of two ZTF afterglow candidates.
- LIGO/Virgo S190425z: LWA1 observations
- LIGO/Virgo S190425z: Insight-HXMT/HE observation
- LIGO/Virgo S190425z: Liverpool Telescope spectroscopy of ZTF19aarykkb
- LIGO/Virgo S190425z - HCT spectroscopy
- LIGO/Virgo S190425z: KPED Follow-Up Observations
- LIGO/Virgo S190425z: CLU/NED Galaxies in the Localization Volume
- LIGO/Virgo S190425z: Candidates from the Zwicky Transient Facility
- LIGO/Virgo S190425z: Fermi GBM Observations
- LIGO/Virgo S190425z: further analysis of INTEGRAL data
- LIGO/VirgoS190425z: HAWC follow-up
- LIGO-Virgo S190421ar:Insight-HXMT/HE observation
- GRB 190424A: Swift detection of a burst
- GRB 190422A: Fermi GBM detection
- GRB 190422A: Swift detection of a burst
- LIGO/Virgo S190421ar: Fermi-GBM Observations
- LIGO/Virgo S190421ar: HAWC follow-up
- Konus-Wind observation of GRB 190415A
- Fermi trigger 576241792 / GRB 190406B: MASTER optical observation
- GRB 190406B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 576241792)
- GRB 190326A: Swift XRT and UVOT follow-up observations
- IPN Triangulation of GRB 190415A
- GRB 190415A: Insight-HXMT/HE detection
- GRB 190407B: AstroSat CZTI detection
- GRB 190411A: AstroSat CZTI detection
- GRB 190411A: Insight-HXMT/HE detection
- LIGO/Virgo S190412m: Fermi-GBM Observations
- LIGO/Virgo S190412m: Insight-HXMT/HE observation
- LIGO/Virgo S190412m: HAWC follow-up
- IceCube-190331A: Swift-XRT Follow-up Observations
- LIGO/Virgo S190408an: TMTS Optical Observation
- LIGO/Virgo S190408an: MASTER 3 OT's more detection
- Konus-Wind observation of GRB 190404B
- GRB 190409A: Swift detection of a possible burst
- LIGO/Virgo S190408an: Insight-HXMT/HE observation
- LIGO/Virgo S190408an: MASTER OT detection
- CORRECTED TARGET NAME: GRB 190408A: MAXI/GSC detection
- GRB 140408A: MAXI/GSC detection
- LIGO-Virgo S190408an: HAWC follow-up
- GRB 190404C: Swift-XRT afterglow detection
- Hard Fermi GRB190404.29/TriggNum576054086: MASTER optical counterpart discovery near PGC020455
- GRB 190404B: CALET Gamma-Ray Burst Monitor detection
- GRB 190331C: AstroSat CZTI detection
- GRB 140404C: MAXI/GSC detection
- GRB 140404B: MAXI/GSC detection
- Trigger 896552: Swift detection of PSR B1055-52
- Konus-Wind observation of GRB 190329A
- GRB 190331B: BOOTES-3/YA optical observations
- GRB 190326B: AstroSat CZTI detection