Skip to main content
Circulars over Kafka event name backfill. See news and announcements

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.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
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"

14 results found.

  1. LIGO/Virgo S190915ak: No significant candidates in TAROT-GRANDMA observations
  2. LIGO/Virgo S190915ak: Updated Sky Localization
  3. LIGO/Virgo S190915ak: No transient candidates in CALET observations
  4. LIGO/Virgo S190915ak: no counterpart candidates in the Swift/BAT observations
  5. LIGO/Virgo S190915ak: Upper limits from Fermi-GBM Observations
  6. LIGO/Virgo S190915ak: No counterpart candidates in Fermi-LAT observations
  7. LIGO/Virgo S190915ak: Coverage and upper limits from MAXI/GSC observations
  8. LIGO/Virgo S190915ak : no neutrino counterpart candidate in ANTARES search
  9. LIGO/Virgo S190915ak: Upper Limits from AGILE-GRID observations
  10. LIGO/Virgo S190915ak: No counterpart candidate in AGILE-MCAL observations
  11. LIGO/Virgo S190915ak: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  12. LIGO/Virgo S190915ak: Upper limits from IceCube neutrino searches
  13. LIGO/Virgo S190915ak: Identification of a GW compact binary merger candidate
  14. LIGO/Virgo S190915ak: Global MASTER-Net observations report

Advanced

Download all Circulars as a .tar.gz archive:
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov