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"5822 results found.
- LIGO/Virgo G299232: LOFAR follow-up
- GRB 171003A: Swift detection of a burst or a Galactic Transient
- LIGO/Virgo G298048: Record of all e-MERLIN results to date on SSS17a
- LIGO/Virgo G299232/GW170825: serendipitous XMM-Newton slew observations
- LIGO/Virgo G298936/GW170823: serendipitous XMM-Newton slew observations
- GRB 170728B: Kottamia R-band observation
- IceCube-170922A: Swift-XRT observations
- LIGO/Virgo G298048: MWA Observations of Error Region
- IceCube-170922A: HAWC follow-up
- GRB 170906A: Insight-HXMT detection
- GRB 170921C: Insight-HXMT detection
- INTEGRAL SPI-ACS observation of AMON IceCube-170922A
- GRB 170921A: RATIR Optical Afterglow Detection and NIR Observations
- LIGO/Virgo G298048: SRT observations of SSS17a in NGC 4993
- GRB 170918A: Insight-HXMT detection
- GRB 170921A: Nanshan optical upper limit
- GRB 170921A: MITSuME Okayama upper limits
- LIGO/Virgo G298048: SSS17a photometry of CHILESCOPE observatory
- LIGO/Virgo G298048: Milliarcsecond imaging of the NGC 4993 central radio source
- Fermi-GBM GRB misclassifications
- GRB 170912C: Insight-HXMT detection
- LIGO/VIRGO G298048: MeerKAT observations of SSS17a
- LIGO/Virgo G297595: NIR Observations following GW170814
- LIGO/Virgo G298048: Danish Telescope Observations of SSS17a/DLT17ck
- LIGO/Virgo G298048: AST3-2 observations of SSS17a/DLT17ck from Antarctica
- GRB 170912A: Prompt enhanced Swift-XRT position
- Konus-Wind observation of GRB 170904A
- LIGO/Virgo G298048: ATCA observations of of SSS17a in NGC 4993
- GRB 170906C: COATLI Observations
- GRB 170906A: MASTER-OAFA (Argentina) early automatic OT detection
- IPN Triangulation of GRB 170904A (long/very bright)
- GRB 170901B: Insight-HXMT detection
- GRB 170904A: Insight-HXMT detection
- LIGO/VIRGO G298048: Precise position of SSS17a based on HST and Gaia
- LIGO/Virgo G299232: LOFAR follow-up
- GRB 170903A: UAFO /ISON optical upper limit
- GRB 170903A: MITSuME Okayama upper limits
- GRB 170903A: Nanshan optical upper limit
- Swift Triggers on MAXI J1535-571
- LIGO/Virgo G297595: DECam observations of BBH merger region of interest
- LIGO/Virgo G298048: Chandra monitoring of the X-ray emission from SSS17a
- LIGO/Virgo G298048: Continued X-ray monitoring and X-ray detection of GW170817 [erratum]]
- LIGO/Virgo G299232: GRAWITA Asiago optical observations
- LIGO/Virgo G298936: PIRATE observations
- LIGO/Virgo G298048: GMRT Follow-up of SSS17a at 1.4 GHz
- LIGO/Virgo G299232: GRAWITA Campo Imperatore optical observations
- LIGO/Virgo G299232: PIRATE observations of MASTER OT J033744.97+723159.0
- LIGO/Virgo G298048: ALMA upper limits on 98 GHz emission from SSS17a
- LIGO/Virgo G298048: Further ATCA follow-up of SSS17a in NGC 4993
- LIGO/Virgo G299232 TZAC/TAROT observations
- LIGO/Virgo G299232/PGWB170825.55: MASTER Global-Net OT inside NGC1343 discovery
- GRB 170827A: Swift detection of a burst
- LIGO/VIRGO G298048: INAF VST-ESO PARANAL observations of NGC4993
- GRB 170822A: AstroSat CZTI detection
- LIGO/Virgo G298048: MASTER Global-Net early optical observations and the Possible KiloNova SSS17a in NGC 4993 photometry and merging rate
- LIGO/Virgo G298048: HAWC follow-up
- LIGO/Virgo G298048: LWA radio observations
- Konus-Wind observation of GRB 170822A
- LIGO/Virgo G298048: INTEGRAL pointed follow-up observations
- LIGO/Virgo G298048: ATCA follow-up of SSS17a in NGC 4993
- LIGO/Virgo G298048: Chandra X-ray observations
- LIGO/Virgo G298048: observations of optical counterpart candidate with CHILESCOPE observatory
- GRB 170822A:BOOTES-5/JGT optical afterglow candidate
- GRB 170822A: Swift detection of a burst
- LIGO/Virgo G298048: MWA Observations of Error Region
- LIGO/Virgo G298048: VLA observation at 15 GHz
- LIGO/Virgo G298048: observations of optical counterpart candidate with CHILESCOPE observatory
- LIGO/Virgo G298048: ATCA 8.5 GHz observations of galaxies in the localisation volume
- LIGO/Virgo G298048: NuSTAR limits on X-ray emission
- LIGO/Virgo G298048: ASKAP follow up
- LIGO/Virgo G298048: TOROS optical counterpart search
- LIGO/Virgo G298048: VLA observation at 6 GHz
- LIGO/Virgo G298048: GROND observations of candidate optical counterpart
- LIGO/Virgo G298048: VLT linear polarimetry
- LIGO/Virgo G298048: Further VLA Observations
- LIGO/Virgo G298048: HSC observations of the OT candidate of G298048
- LIGO/Virgo G298048: GROND photometry of candidate optical counterpart reveals brightening in the NIR
- LIGO/Virgo G298048: Rapid Evolution of Possible Counterpart
- LIGO/Virgo G298048: ATCA upper limits on radio emission from optical source SSS17a in NGC 4993
- LIGO/Virgo G298048: Brightening of Possible Counterpart
- LIGO/Virgo G298048: AGILE-GRID analysis of the potential counterpart field
- LIGO/Virgo G298048: Observation of the potential optical counterpart in NGC 4993
- LIGO/Virgo G298048: Subaru HSC z-band photometry of the possible optical counterpart
- LIGO/Virgo G298048: SkyMapper uvgri photometry of the candidate in NGC 4933
- LIGO/Virgo G298048: ATCA detection of a radio source coincident with NGC 4993
- LIGO/Virgo G298048: TZAC TAROT Reunion (TRE) observations
- LIGO/Virgo G298048: REM optical/NIR observations
- LIGO/Virgo G298048: Pan-STARRS detections and izy photometry of the possible optical/NIR counterpart in NGC4993
- LIGO/Virgo G298048: Magellan g-band Imaging of the Potential Optical Counterpart Associated with NGC 4993
- LIGO/Virgo G298048: Subaru HSC follow-up observations
- LIGO/VIRGO G298048: Magellan Optical Spectrum of the Potential Optical Counterpart Associated with NGC 4993
- LIGO/Virgo G298048: VLA Detection
- LIGO/Virgo G298048: Optical Candidate Shows No Evidence for Previous Activity in Archival SkyMapper Transient Survey Data
- LIGO/Virgo G298048: Optical Candidate Shows No Evidence for Previous Activity in Archival ASAS-SN Data
- LIGO/Virgo G298048: DLT40 optical candidate
- LIGO/Virgo G298048: Potential optical counterpart discovered by Swope telescope
- LIGO/Virgo G297595: MASTER MASTER Bright PSN detection in error-box
- LIGO/Virgo G297595: INAF VST-ESO PARANAL observations
- LIGO/Virgo G297595: Subaru Hyper Suprime-Cam follow-up observations
- LIGO/Virgo G296853: Pierre Auger Observatory neutrino follow-up