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"
200 results found.
- LIGO/Virgo G298048: TOROS optical counterpart search (continuation)
- LIGO/Virgo G298048: TOROS optical counterpart search
- LIGO/Virgo G298048: optical observations of CHILESCOPE observatory
- LIGO/Virgo G298048: Pan-STARRS izy photometry monitoring of SSS17a/DLT17ck
- LIGO/Virgo G298048: VLA observation at 6 GHz
- LIGO/Virgo G298048: Continued VLA observations
- LIGO/Virgo G298048: Possible X-ray detection with Swift
- LIGO/VIRGO G298048: SALT optical spectra of the candidate optical/NIR counterpart of the gravitational wave G298048 in NGC4993.
- LIGO/Virgo G298048: Etelman Observatory observation of the potential LIGO EM counterpart SSS17a
- LIGO/Virgo G298048: GROND observations of candidate optical counterpart
- LIGO/Virgo G298048: Continued observation for DLT17ck
- LIGO/Virgo G298048: GMRT Follow-up of SSS17a
- LIGO/Virgo G298048: La Silla - QUEST archival non-detections of of LIGO EM counterpart SSS17a
- LIGO/VIRGO G298048: INAF VST-ESO PARANAL observations
- LIGO/Virgo G298048: KMTNet and other optical follow-up observations
- LIGO/Virgo G298048: further REM optical/NIR observations of candidate in NGC 4993
- LIGO/Virgo G298048: Subaru HSC z-band photometry confirms the fading nature of SSS17a
- LIGO/Virgo G298048: VLT linear polarimetry
- LIGO/Virgo G298048: GRAWITA VLT/X-shooter observations
- LIGO/Virgo G298048: NOT near-infrared observations of SSS17a
- LIGO/Virgo G298048: Further Pan-STARRS izy photometry confirms rapid fading of SSS17a/DLT17ck in i and z bands
- LIGO/Virgo G298048: Further VLA Observations
- LIGO/Virgo G298048: VLBA observations of the possible counterpart SSS17a in NGC 4993
- LIGO/Virgo G298048: MASTER photometry of the SSS17a in NGC 4993
- LIGO/Virgo G298048: HSC observations of the OT candidate of G298048
- LIGO/Virgo G298048: Possible features in the spectrum of GW counterpart SSS17a
- LIGO/Virgo G298048: GROND photometry of candidate optical counterpart reveals brightening in the NIR
- LIGO/Virgo G298048: Additional Swope Observations of SSS17a
- LIGO/VIRGO G298048: ePESSTO optical spectra of the candidate optical/NIR counterpart of the gravitational wave G298048 in NGC4993.
- LIGO/Virgo G298048: Rapid Evolution of Possible Counterpart
- LIGO/Virgo G298048: Observed fading of optical counterpart SSS17a
- LIGO/Virgo G298048: Continued observation for DLT17ck
- LIGO/VIRGO G298048: Expansion Velocity of SSS17a Consistent With Relativistic Merger Ejecta
- LIGO/Virgo G298048: optical spectral energy distribution of SSS17a
- LIGO/Virgo G298048: prior photometry from VISTA Hemisphere Survey
- LIGO/Virgo G298048: Archival 2MASS and Spitzer non-detections of the potential LIGO EM counterpart SSS17a
- LIGO/Virgo G298048: ATCA upper limits on radio emission from optical source SSS17a in NGC 4993
- LIGO/Virgo G298048: Continued Swift UV and X-ray Monitoring of SSS17a
- LIGO/Virgo G298048: Archival VLA observations
- LIGO/Virgo G298048: New MASTER observations of the OT in NGC 4993
- LIGO/Virgo G298048: Additional Gemini-South acknowledgements
- LIGO/Virgo G298048: UPDATE on IceCube neutrino candidates --- no coincidence with newest GW skymap
- LIGO/Virgo G298048: Correction to Swope photometry announced in LVC GCN 21529
- LIGO/Virgo G298048: Moderate dimming or no brightening of the optical counterpart candidate?
- 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: ASKAP search for fast radio bursts
- 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: Likelihood of SSS17a Being an Unrelated Extragalactic Transient in NGC 4993
- LIGO/Virgo G298048: REM optical/NIR observations
- LIGO/Virgo G298048, Fermi GBM trigger 524666471/170817.529: MAXI/GSC observations
- LIGO/Virgo G298048: HCT observations
- LIGO/Virgo G298048: Pan-STARRS detections and izy photometry of the possible optical/NIR counterpart in NGC4993
- LIGO/Virgo G298048: Gemini-South Near-Infrared Photometry of the Optical Transient Candidate
- LIGO/Virgo G298048: Magellan g-band Imaging of the Potential Optical Counterpart Associated with NGC 4993
- LIGO/VIRGO G298048: Swift UVOT detection and XRT upper limits
- LIGO/Virgo G298048: Subaru HSC follow-up observations
- LIGO/Virgo G298048: VLA Refined Analysis
- LIGO/VIRGO G298048: Magellan Optical Spectrum of the Potential Optical Counterpart Associated with NGC 4993
- LIGO/Virgo G298048: MASTER observations of the NGC 4993
- LIGO/Virgo G298048: VLA Detection
- LIGO/Virgo G298048: VISTA/VIRCAM detection of candidate counterpart
- LIGO/Virgo G298048: Galaxy-Targeted Optical Followup With Las Cumbres Observatory
- LIGO/Virgo G298048: Optical Candidate Shows No Evidence for Previous Activity in Archival SkyMapper Transient Survey Data
- LIGO/VIRGO G298048: The Potential Optical Counterpart in NGC 4993 Has Afterglow-Like Colors
- LIGO/Virgo G298048: DLT40 follow-up observation
- LIGO/Virgo G298048: Las Cumbres Observatory Detection of The Possible Optical Counterpart in NGC 4993
- LIGO/Virgo G298048: ATCA observations of candidate host galaxies
- LIGO/Virgo G298048: Inspection of archival HST data at the position of the potential optical counterpart
- LIGO/Virgo G298048: Nearby Galaxies in the Localization Volume using the updated sky map computed using LALInference
- LIGO/Virgo G298048 : Fermi-LAT search for a high-energy gamma-ray counterpart
- LIGO/Virgo G298048: Optical Candidate Shows No Evidence for Previous Activity in Archival ASAS-SN Data
- LIGO/Virgo G298048: REM optical/NIR observations of candidate in NGC 4993
- LIGO/Virgo G298048: DLT40 optical candidate
- LIGO/Virgo G298048: DECam optical candidate
- LIGO/Virgo G298048: Potential optical counterpart discovered by Swope telescope
- LIGO/Virgo G298048 - Update on Fermi/GBM GRB 170817A Analysis
- LIGO/Virgo G298048: Updated sky map from gravitational-wave data
- LIGO/Virgo G298048: AGILE GRID observations
- LIGO/Virgo G298048: AGILE MCAL observations
- LIGO/Virgo G298048: Swift/BAT data search
- LIGO/Virgo G298048 ANTARES search
- LIGO/Virgo G298048: Nearby Galaxies in the Localization Volume with Face-on Assumption
- LIGO/Virgo G298048: Nearby Galaxies in the Localization Volume
- LIGO/Virgo G298048: Insight-HXMT observations
- LIGO/Virgo G298048: Potential host galaxies from the GLADE catalog
- LIGO/Virgo G298048: IPN triangulation of Fermi/GBM trigger 524666471/170817529
- LIGO/Virgo G298048: Astrosat CZTI upper limits
- LIGO/Virgo G298048: Further analysis of a binary neutron star candidate with updated sky localization
- LIGO/Virgo G298048: COINCIDENT IceCube neutrino candidate with Fermi GBM trigger 524666471/170817529
- LIGO/Virgo G298048: correction to the luminosity distance reported in GCN 21509
- LIGO/Virgo G298048: Identification of a binary neutron star candidate coincident with Fermi GBM trigger 524666471/170817529
- LIGO/Virgo G298048: FOUND COINCIDENT IceCube neutrino observation
- LIGO/Virgo G298048: INTEGRAL detection of a prompt gamma-ray counterpart
- LIGO/Virgo G298048: Fermi GBM trigger 170817.529 and LIGO single IFO trigger
- LIGO/Virgo G298048: Fermi GBM trigger 524666471/170817529: LIGO/Virgo Identification of a possible gravitational-wave counterpart