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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.

Lucene Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

47 results found.

  1. GRB 230307A: JWST second-epoch observations
  2. GRB 230307A: iTelescope optical upper limit (likely)
  3. GRB 230307A: JWST NIRSpec observations, possible higher redshift
  4. GRB 230307A: further analysis of the Konus-Wind detection and rest-frame energetics
  5. GRB 230307A: good match with kilonova models
  6. GRB 230307A: short mininum variability timescale compatible with a merger origin
  7. GRB 230307A: JWST observations consistent with the presence of a kilonova
  8. GRB 230307A: Chandra late-time detection of the X-ray afterglow
  9. GRB 230307A: Bad Time Intervals for Fermi GBM data
  10. GRB 230307A: Continued Gemini-South observations confirm rapid optical fading
  11. GRB 230307A: Far off-axis NuSTAR detection of the GRB
  12. GRB 230307A: ATCA radio detection
  13. GRB 230307A: INTEGRAL upper limit on Hard X-ray afterglow
  14. GRB 230307A: Swift/UVOT detection
  15. GRB 230307A: soft X-ray detection with LEIA
  16. GRB 230307A: Swift-XRT afterglow detection
  17. Further improved IPN localization for GRB 230307A
  18. GRB 230307A: SOAR/Goodman detection of the possible host galaxy
  19. GRB 230307A: GECKO optical observations and detections of the afterglow
  20. GRB 230307A: MAXI/GSC upper limit
  21. GRB 230307A: Gemini-South Confirmation of the Optical Afterglow
  22. GRB 230307A: AGILE/MCAL analysis
  23. GRB 230307A: ATLAS information on the ULTRACAM optical afterglow candidate
  24. GRB 230307A: Erratum of the GCN 33441
  25. GRB 230307A: Possible optical afterglow
  26. GRB 230307A: ASO-S/HXI detection
  27. GRB 230307A: AstroSat LAXPC detection
  28. GRB 230307A: optical upper limit
  29. GRB 230307A: Swift/BAT upper limits on the early afterglow
  30. GRB 230307A: Upper limits from a neutrino search with IceCube
  31. GRB 230307A: Swift-XRT observations
  32. Fermi GRB 230307A: Global MASTER-Net observations report
  33. Konus-Wind detection of GRB 230307A
  34. Improved IPN localization for GRB 230307A
  35. GRB 230307A: VZLUSAT-2 detection
  36. GRB 230307A: Tiled Swift observations
  37. GRB 230307A: Detection by GRBAlpha
  38. GRB 230307A: BALROG localization (Fermi Trigger 699896651/ GRB 230307656)
  39. GRB 230307A: AstroSat CZTI detection
  40. GRB 230307A: possibly the second highest GRB energy fluence ever identified
  41. IPN triangulation of GRB 230307A (long/very bright)
  42. GRB 230307A: AGILE/MCAL detection
  43. GRB 230307A: Fermi GBM Observation of a very bright burst
  44. Solar Orbiter STIX observation of GRB 230307A
  45. GRB 230307A: Fermi GBM detection of a very bright GRB
  46. GRB 230307A: GECAM detection of an extremely bright burst
  47. GRB 230307A: Fermi GBM Final Real-time Localization

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