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"19548 results found.
- LIGO/Virgo S190814bv: No radio counterpart to DG19wxnjc/AT2019npv in ASKAP observations
- GRB 190824A: Enhanced Swift-XRT position
- Fermi GBM-190816: Updated localization of subthreshold GRB-GW candidate
- GRB 190824A: Swift detection of a burst
- GRB 190823A: Tiled Swift observations
- LIGO/Virgo S190814bv: GROND follow-up observations of AT2019npv
- GRB 190821A: Swift/UVOT Upper Limits
- LIGO/Virgo S190814bv: NIR imaging follow-up of ASKAP transient
- GRB 190821A: MASTER VWFC syncronous optical observations
- LIGO/Virgo S190814bv: ENGRAVE VLT/HAWK-I observations and archival detection of the CFHT candidate
- LIGO/Virgo S190814bv: No radio counterpart detected in ASKAP observations
- GRB 190821A: Enhanced Swift-XRT position
- Fermi GBM-190816: Upper Limits from Swift/BAT Observations
- GRB 190821A: T60 Les Makes optical detection of the afterglow
- Swift GRB190821.72 Global MASTER-Net observations report
- GRB 190821A: Swift detection of a burst
- Fermi GBM-190816: No counterpart candidates in Fermi-LAT observations
- Fermi-LAT Gamma-ray Observations of IceCube-190819A
- LIGO/Virgo S190814bv: RATIR Optical observations of DECam transients
- LIGO/Virgo GBM-190816: no counterpart candidates in the Swift/BAT Observations
- IceCube-190819A - HAWC follow-up
- Fermi GBM-190816: No counterpart candidates in HAWC observations
- LIGO/Virgo S190814bv: No neutrino candidates at Pierre Auger Observatory
- Fermi GBM-190816+LIGO/Virgo : no neutrino counterpart candidate in ANTARES search
- Fermi GBM-190816: Location-dependent upper limits from INTEGRAL/SPI-ACS prompt observation
- Fermi GBM-190816: A subthreshold GRB candidate potentially associated with a subthreshold LIGO/Virgo compact binary merger candidate
- IceCube-190819A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- LIGO/Virgo S190814bv: No candidates from image subtraction in DCT galaxy targeted search
- LIGO/Virgo S190814bv: WIRC NIR imaging follow-up of DECam transients
- LIGO/VIRGO S190814bv: AbAO non-detection of AT2019nme
- LIGO/Virgo S190814bv: No candidates found in J-GEM follow-up observations
- LIGO/Virgo S190814bv: Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo S190814bv : No Counterpart Candidates in Continued Galaxy Targeted Search with Magellan
- LIGO/Virgo S190814bv: No candidates found in J-GEM follow-up observations
- LIGO/VIRGO S190814bv: No candidates from ATLAS observations
- LIGO/Virgo S190814bv: No candidates from DCT galaxy targeted search and observations of DECam-GROWTH candidates
- LIGO/Virgo S190814bv: GROND imaging of candidate galaxies
- SUBJECT: LIGO/Virgo S190814bv: GRAWITA VST-ESO PARANAL observations
- 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
- LIGO/Virgo S190814bv: No Counterparts in DDOTI/OAN Optical Observations
- LIGO/Virgo S190814bv: no counterpart candidates in Thacher imaging
- LIGO/Virgo S190814bv: no counterpart candidates in Swope imaging
- LIGO/Virgo S190814bv: no counterpart candidates in Nickel/Direct imaging and non-detections of 2019nmd and 2019nme
- LIGO/Virgo S190814bv: ATLAS forced photometry non-detections of DESGW candidates
- Non-detection of DESGW-190814a in ZTF forced photometry
- LIGO/Virgo S190814bv: no counterpart candidates in Keck I MOSFIRE imaging
- LIGO/Virgo S190814bv: KMTNet observation
- LIGO/Virgo S190814bv: No counterpart candidates in the Swift/BAT Observations
- LIGO/Virgo S190814bv: MeerLICHT coverage second preliminary skymap
- LIGO/Virgo S190814bv: no candidates from GOTO imaging observations
- LIGO/Virgo S190814bv : no neutrino counterpart candidate in ANTARES search
- LIGO/Virgo S190814bv: Upper limits from Fermi-GBM Observations
- LIGO/Virgo S190814bv: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- IPN triangulation of GRB 190810A (short)
- HAWC-190806A: upper limits from INTEGRAL SPI-ACS and IBIS prompt observation
- Trigger_11505: Tiled Swift observations
- LIGO/Virgo S190808ae: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190808ae: No counterpart candidates in HAWC observations
- GRB 190808B: Fermi GBM Final Real-time Localization
- GRB 190808A: Fermi GBM Final Real-time Localization
- GRB 190804B: Swift-XRT afterglow detection
- Alert from the HAWC Burst Monitor
- GRB 190805B: Swift-XRT observations
- GRB 190805B: Tiled Swift observations
- GRB 190804B: Tiled Swift observations
- GRB 190731A: Swift/UVOT Upper Limits
- GRB 190731A: no OT detected by MASTER
- IceCube 190730A: No counterpart candidates or blazar activity in GOTO observations
- GRB 190731A: Swift-XRT afterglow detection
- IPN Triangulation of GRB 190731A
- GRB 190731A: Swift ToO observations
- Fermi-LAT Gamma-ray Observations of IceCube-190730A
- IceCube-190730A - HAWC follow-up
- IceCube 190730A: one weakly associated counterpart candidates in INTEGRAL SPI-ACS, and IBIS prompt observation
- LIGO/Virgo S190707q: AstroSat CZTI upper limits
- LIGO/Virgo S190728q: GRAWITA VST-ESO PARANAL observations
- LIGO/Virgo S190728q/IceCube neutrino candidate: No counterpart candidates in the Swift-XRT Observations
- S190728q: MASTER multiple previous outbursts detection of ZTF19abjethn=AT2019lvs
- LIGO/Virgo S190728q: No counterpart candidates in the Swift/BAT Observations
- LIGO/Virgo S190728q: Optical Candidate from the Zwicky Transient Facility ZTF19abjethn
- LIGO/Virgo S190728q: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S190728q : no neutrino counterpart candidate in ANTARES search
- LIGO/Virgo S190728q: No counterpart candidates in HAWC observations
- LIGO/Virgo S190728q: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- LIGO/Virgo S190727h: No counterpart candidates in the Swift/BAT Observations
- LIGO/Virgo S190727h: No counterpart candidates in Fermi-LAT observations
- LIGO/Virgo S190727h: possible counterpart candidate in SPI-ACS/INTEGRAL
- LIGO/Virgo S190727h: No counterpart candidates in HAWC observations
- LIGO/Virgo S190727h : no neutrino counterpart candidate in ANTARES search
- LIGO/Virgo S190727h: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
- LIGO/Virgo S190727h: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo S190727h: Identification of a GW compact binary merger candidate
- LIGO/Virgo S190720a: Thacher Observatory follow-up observations
- GRB 190719C: optical afterglow confirmation
- LIGO/Virgo S190720a: No counterpart candidates in CNEOST observations
- LIGO/Virgo S190720a: No counterpart candidates in Fermi-LAT observations
- GRB 190719C: Swift/UVOT Upper Limits
- LIGO/Virgo S190720a: No counterpart candidates in the Swift/BAT Observations
- LIGO/Virgo S190720a: Upper limits from Fermi-GBM Observations