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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.

Advanced Search Examples (click to copy):

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

3758 results found.

  1. SGR1900+14: Second Burst Localized by HETE
  2. IPN triangulation of GRB010613
  3. GRB000418: HST/STIS Second-epoch Observations
  4. X-ray precursors to the large flare from SGR 1900+14
  5. SGR 1900+14 : RXTE observations
  6. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  7. GRB010412: BeppoSAX GRBM and WFC observations
  8. GRB010222: Chandra X-ray Observatory Observation
  9. GRB010222 - Optical observation
  10. GRB010222: Optical observation and decay
  11. GRB 010222 HST/Chandra TOO
  12. GRB010222: Optical Observations
  13. GRB 010220, simultaneous optical observations
  14. GRB010126 optical observations
  15. GRB001007, Radio observations
  16. GRB000926 - Amateur Optical Observations
  17. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  18. IPN localization of GRB000801
  19. GRB 990510: Possible detection of a host galaxy
  20. GRB 990510 Host Galaxy Discovery
  21. possible optical counterpart of GRB 000630
  22. IPN annulus for GRB000620
  23. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  24. The redshift of GRB 000418
  25. Correction to IPN error box for GRB000419
  26. GRB 000408, optical observations
  27. GRB000315 [IPN Positions]
  28. GRB000226 [IPN Position]
  29. IPN error boxes for GRB991229
  30. GRB 991106, LOTIS Optical Observations
  31. GRB991105: SAX-GRBM/-WFC detection
  32. GRB 991014, radio observations
  33. GRB 991014, Optical Observations
  34. IPN/NFI error box for GRB991014
  35. GRB990907: BeppoSAX follow up and X-ray afterglow
  36. GRB990806: BATSE Observations
  37. BeppoSAX ALERT GRB990806: Summer GRB
  38. Late-time HST/STIS Observations of GRB 990510
  39. GRB 990510: BeppoSAX/GRBM observations
  40. GRB980425 Optical observations of exponential decline at late time
  41. GRB990321 REFINED IPN ANNULUS
  42. GRB990308, Possible new SGR~0209+70
  43. GRB 990123: New Constraints on Possible Foreground Galaxies
  44. GRB 990123: Continued Radio Observations
  45. GRB 981226: radio variable
  46. GRB 980613: Spectroscopy of the host galaxy
  47. GRB981226 Optical Observations
  48. GRB 981226 optical observations
  49. GRB980613 Optical Observations
  50. GRB 980613 Near-IR observations
  51. GRB 980613: Optical transient and its host galaxy
  52. GRB 980613 optical observations
  53. GRB 980519
  54. GRB980425: Radio Observations
  55. GRB980326 optical observations
  56. Optical Observations of GRB 970508
  57. GRB 971214: Redshift from Keck Observations
  58. GRB 970828: Palomar Observations

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