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.
- LIGO/Virgo S190901ap : No significant candidates found in GRANDMA citizen science observations
- GRB 190901A: AstroSat CZTI detection
- ZTF19abvizsw/AT2019pim, search for GRB in SPI-ACS/INTEGRAL data
- Fermi trigger No 589561732 Global MASTER-Net observations report
- ZTF19abvizsw: AbAO and CrAO photometry
- GRB 190829A observations in CrAO, photometry of the SN
- Fermi trigger No 589487114 Global MASTER-Net observations report
- GRB 190906B: Fermi GBM Final Real-time Localization
- Fermi trigger No 589419513 Global MASTER-Net observations report
- LIGO/Virgo S190814bv: GRAWITA VST-ESO PARANAL observations and independent transient candidates discovery.
- LIGO/Virgo S190901ap : No significant candidates in TAROT-GRANDMA
- LIGO/Virgo S190901ap: NOT spectroscopy of AT2019pjv
- LIGO/Virgo S190901ap: No counterpart candidates in KAIT observations
- LIGO/Virgo S190901ap: Dabancheng-0.5m optical observations of AT2019pjv
- GRB 190829A: Liverpool Telescope observations of a slow supernova rise
- LIGO/Virgo S190901ap: Additional candidates from the Zwicky Transient Facility
- ZTF19abvizsw: COATLI Optical Observations
- LIGO/Virgo S190901ap: GOTO optical coverage and detection of AT2019pjv
- GRB 190829A: MASTER confirmation of GROND SN
- LIGO/Virgo S190901ap : GRAWITA photometric observation of candidate ZTFabvizsw and GCN 25618 revision
- LIGO/Virgo S190901ap: MASTER OT J171434.95+280725.6/AT2019pjv detection
- LIGO/Virgo S190901ap: no counterpart candidate in the SVOM/GWAC observations
- LIGO/Virgo S190901ap: Upper limits from CALET observations.
- GRB 190901A: Insight-HXMT/HE detection
- LIGO/Virgo S190901ap: Upper limits from Insight-HXMT/HE observations
- Fermi trigger No 589263065 Global MASTER-Net observations report
- Liverpool Telescope observations of ZTF19abvizsw, a candidate untriggered GRB afterglow
- Fermi trigger No 589223981 Global MASTER-Net observations report
- LIGO/Virgo S190901ap: Additional observations from the Zwicky Transient Facility
- LIGO/Virgo S190901ap: Upper limits from AGILE-GRID observations
- LIGO/Virgo S190828l: no counterpart candidate in the SVOM/GWAC observations
- LIGO/Virgo S190901ap: No neutrino candidates at Pierre Auger Observatory
- LIGO/Virgo S190901ap: No counterpart candidates in Fermi-LAT observations
- GRB 190829A: Flattening of optical light curve from continued Liverpool Telescope photometry
- 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 AGILE-MCAL observations
- LIGO/Virgo S190901ap: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190901ap : no neutrino counterpart candidate in ANTARES search
- LIGO/Virgo S190901ap Global MASTER-Net observations report
- LIGO/Virgo S190901ap: Identification of a GW compact binary merger candidate
- LIGO/Virgo S190901ap: No counterpart candidates in INTEGRAL SPI-ACS,prompt observation
- LIGO/Virgo S190901ap: Upper limits from IceCube neutrino searches
- Fermi trigger No 589065714 Global MASTER-Net observations report
- Fermi trigger No 589060361 Global MASTER-Net observations report
- LIGO/Virgo S190814bv : No significant candidates in TAROT-GRANDMA observations
- GRB 190829A: Continued fading inferred from Liverpool Telescope photometry
- LIGO/Virgo S190828j : No significant candidates in TAROT-GRANDMA observations
- LIGO/Virgo S190828l: No significant candidates in TAROT-GRANDMA observations
- GRB 190829A: AGILE-GRID upper limits
- Fermi trigger No 588838851 Global MASTER-Net observations report
- LIGO/Virgo S190828l: No counterpart candidates in KAIT observations
- LIGO/Virgo S190828j: No counterpart candidates in KAIT observations
- GRB 190828B: Swift detection of a burst
- LIGO/Virgo S190828l: No counterpart candidates in AGILE-MCAL observations
- LIGO/Virgo S190828l : no neutrino counterpart candidate in ANTARES search
- LIGO/Virgo S190828l: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- LIGO/Virgo S190814bv : Magellan IMACS Spectrum of AT2019npv classified as a Type Ib supernova
- Fermi trigger No 588398821 Global MASTER-Net observations report
- Fermi trigger No 588350802 Global MASTER-Net observations report
- LIGO/Virgo S190814bv: No radio counterpart detected in ASKAP observations
- LIGO/Virgo S190814bv: No Optical Counterpart Candidates in Second-Epoch Lick/KAIT Observations
- GRB 190821A: Swift detection of a burst
- LIGO/Virgo S190814bv: RATIR Optical observations of DECam transients
- LIGO/Virgo S190814bv: No candidates from image subtraction in DCT galaxy targeted search
- LIGO/Virgo S190814bv : No Counterpart Candidates in Continued Galaxy Targeted Search with Magellan
- LIGO/Virgo S190814bv: No candidates from DCT galaxy targeted search and observations of DECam-GROWTH candidates
- S190814bv: MASTER analysis of DECam-GROWTH candidates
- LIGO/Virgo S190814bv : No Counterpart Candidates in Galaxy Targeted Search with Magellan
- LIGO/Virgo S190814bv: No Candidates Found in Wide-Field Infrared Search with Palomar Gattini-IR
- 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 TOROS observations
- LIGO/Virgo S190814bv: no counterpart candidates in Nickel/Direct imaging and non-detections of 2019nmd and 2019nme
- LIGO/Virgo S190814bv Global MASTER-Net optical observations
- LIGO/Virgo S190814bv : No counterpart candidate in TAROT-GRANDMA observations
- LIGO/Virgo S190814bv: Liverpool Telescope imaging of selected galaxies
- LIGO/Virgo S190814bv Global MASTER-Net observations report
- Fermi trigger No 587392154 Global MASTER-Net observations report
- GRB 190813A: Fermi GBM Final Real-time Localization
- FRB 190806: MASTER optical observation
- Fermi trigger No 586800758 Global MASTER-Net observations report
- GRB 190805B: MAXI/GSC detection
- GRB 190804B: MAXI/GSC detection
- Fermi trigger No 586574612 Global MASTER-Net observations report
- LIGO/Virgo S190728q: ZTF Forced Photometry for PS1 and DECam-GROWTH optical candidates, and a note on DECam Photometry from GCN 25215
- LIGO/Virgo S190707q: 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: No counterpart candidates in KAIT observations
- LIGO/Virgo S190727h: No counterpart candidates in KAIT observations
- LIGO/Virgo S190727h: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S190720a: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S190720a: No counterpart candidates in KAIT observations
- GRB 190720A: BALROG localization (Fermi Trigger 585326534 / GRB 190720613)
- GRB 190720A: Fermi GBM Final Real-time Localization
- LIGO/Virgo S190720a: Identification of a GW compact binary merger candidate
- LIGO/Virgo S190718y: No counterpart candidates in KAIT observations
- Fermi trigger No 585007213 Global MASTER-Net observations report
- Fermi trigger No 584804684 Global MASTER-Net observations report