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"

26 results found.

  1. LIGO/Virgo S200105ae: Upper limits from Konus-Wind observations
  2. LIGO/Virgo S200105ae: More candidates from the Zwicky Transient Facility
  3. LIGO/Virgo S200105ae: AT2020pq, AT2020ps and AT2020pv 10.4m GTC spectroscopy
  4. LIGO/Virgo S200105ae: AT2020pp and AT2020py 10.4m GTC spectroscopy
  5. LIGO/Virgo S200105ae: AT2020oo 10.4m GTC spectroscopy
  6. LIGO/Virgo S200105ae: Updated Sky Localization and EM-Bright Probabilities
  7. LIGO/Virgo S200105ae : No significant candidates in TAROT - FRAM - GRANDMA observations.
  8. LIGO/Virgo S200105ae: Gaia Photometric Alerts transient candidate
  9. LIGO/Virgo S200105ae: GW data still under study
  10. LIGO/Virgo S200105ae: Candidates from the Zwicky Transient Facility
  11. LIGO/Virgo S200105ae: Upper limits from CALET observations.
  12. LIGO/Virgo S200105ae: Upper Limits from the Zwicky Transient Facility
  13. LIGO/Virgo S200105ae: Further study ongoing for GW compact binary merger candidate
  14. LIGO/Virgo 200105ae: No counterpart candidates in Fermi-LAT observations
  15. LIGO/Virgo S200105ae: AstroSat CZTI upper limits
  16. LIGO/Virgo S200105ae: Coverage and upper limits from MAXI/GSC observations
  17. LIGO/Virgo S200105ae: No counterpart candidates in HAWC observations
  18. LIGO/Virgo S200105ae: no counterpart candidates in the Swift/BAT observations
  19. LIGO/Virgo S200105ae: Upper limits from IceCube neutrino searches
  20. LIGO/Virgo S200105ae: not observable by AGILE-MCAL
  21. LIGO/Virgo S200105ae: Global MASTER-Net observations report
  22. LIGO/Virgo S200105ae: Upper limits from Fermi-GBM Observations
  23. LIGO/Virgo S200105ae: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  24. LIGO/Virgo S200105ae : no neutrino counterpart candidate in ANTARES search
  25. LIGO/Virgo S200105ae: We have issued GCN Notices to support automated processing
  26. LIGO/Virgo S200105ae: A subthreshold GW compact binary merger candidate

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