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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"

3663 results found.

  1. BeppoSAX ALERT: Possible X-ray rich GRB011030
  2. GRB010928(=H1770): Localization of a Long GRB by HETE
  3. GRB 010222: HST observations -- host galaxy and late-time decay
  4. GCN and HETE status
  5. BeppoSAX/GRBM detection of GRB010728
  6. SGR1900+14: Second Burst Localized by HETE
  7. IPN triangulation of GRB010613
  8. GRB000418: HST/STIS Second-epoch Observations
  9. X-ray precursors to the large flare from SGR 1900+14
  10. SGR 1900+14 : RXTE observations
  11. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  12. GRB010412: BeppoSAX GRBM and WFC observations
  13. GRB010222: Chandra X-ray Observatory Observation
  14. GRB010222 - Optical observation
  15. GRB010222: Optical observation and decay
  16. GRB 010222 HST/Chandra TOO
  17. GRB010222: Optical Observations
  18. GRB 010220, simultaneous optical observations
  19. GRB010126 optical observations
  20. GRB001007, Radio observations
  21. GRB000926 - Amateur Optical Observations
  22. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  23. IPN localization of GRB000801
  24. GRB 990510: Possible detection of a host galaxy
  25. GRB 990510 Host Galaxy Discovery
  26. possible optical counterpart of GRB 000630
  27. IPN annulus for GRB000620
  28. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  29. The redshift of GRB 000418
  30. Correction to IPN error box for GRB000419
  31. GRB 000408, optical observations
  32. GRB000315 [IPN Positions]
  33. GRB000226 [IPN Position]
  34. IPN error boxes for GRB991229
  35. GRB 991106, LOTIS Optical Observations
  36. GRB991105: SAX-GRBM/-WFC detection
  37. GRB 991014, radio observations
  38. GRB 991014, Optical Observations
  39. IPN/NFI error box for GRB991014
  40. GRB990907: BeppoSAX follow up and X-ray afterglow
  41. GRB990806: BATSE Observations
  42. BeppoSAX ALERT GRB990806: Summer GRB
  43. Late-time HST/STIS Observations of GRB 990510
  44. GRB 990510: BeppoSAX/GRBM observations
  45. GRB980425 Optical observations of exponential decline at late time
  46. GRB990321 REFINED IPN ANNULUS
  47. GRB990308, Possible new SGR~0209+70
  48. GRB 990123: New Constraints on Possible Foreground Galaxies
  49. GRB 990123: Continued Radio Observations
  50. GRB 981226: radio variable
  51. GRB 980613: Spectroscopy of the host galaxy
  52. GRB981226 Optical Observations
  53. GRB 981226 optical observations
  54. GRB980613 Optical Observations
  55. GRB 980613 Near-IR observations
  56. GRB 980613: Optical transient and its host galaxy
  57. GRB 980613 optical observations
  58. GRB 980519
  59. GRB980425: Radio Observations
  60. GRB980326 optical observations
  61. Optical Observations of GRB 970508
  62. GRB 971214: Redshift from Keck Observations
  63. GRB 970828: Palomar Observations

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