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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"

24770 results found.

  1. Probable SGR or Short Duration GRB Detected by HETE
  2. GCN and HETE status
  3. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  4. GRB 010222 - WHT BVRI images
  5. SGR1900+14 burst seen by HETE: BeppoSAX data
  6. GRB 010629 Optical Observations
  7. SGR1900+14: High Fluence Burst Localized by HETE
  8. GRB010629, optical observations
  9. GRB010629: A Burst Localized by HETE
  10. SGR1900+14: Second Burst Localized by HETE
  11. SGR1900+14: A Burst Localized by HETE
  12. SGR1806-20: A Second, Intense Burst Localized by HETE
  13. SGR1806-20: Localization by HETE
  14. HETE Fully-Automated GCN Notices
  15. GRB000301C: Late-time HST/STIS observation
  16. GRB010518: a faint BeppoSAX detection
  17. GRB000418: HST/STIS Second-epoch Observations
  18. X-ray precursors to the large flare from SGR 1900+14
  19. GRB010427, Gamma Ray Observations
  20. SGR 1900+14: No evidence of extended X-ray emission
  21. SGR 1900+14 : RXTE observations
  22. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  23. SGR 1900+14: Correction to GCN 1049
  24. GRB 010222 /corrections to VBT data
  25. Millimeter observation of SGR 1900+14
  26. SGR 1900+14: Detection of extended X-ray emission
  27. SGR 1900+14, Chandra observations
  28. SGR1900+14, I-band observations
  29. GRB010412, field photometry
  30. Giant flare from SGR1900+14
  31. GRB 010326b Optical Observations
  32. GRB010412: BeppoSAX GRBM and WFC observations
  33. GRB010324, revised field photometry
  34. REVISED LOCATION OF GRB010326A
  35. GRB 980326: Late-time HST/STIS observations
  36. GRB010324, field photometry
  37. GRB010326B, field photometry
  38. GRB010326, field photometry
  39. GRB010220, field photometry
  40. Further Optical Observations of GRB 010324
  41. GRB010222, CXO X-ray observations
  42. GRB010324, optical observations
  43. GRB010326B: Localization by HETE (2nd GRB for this date)
  44. GRB 010326 optical observations
  45. GRB010326: Refined Localization by HETE
  46. GRB010326: Localization by HETE
  47. Optical Observations of GRB 010324
  48. GRB010222, late-time optical observation
  49. Support extension to the BeppoSAX mission
  50. GRB 010222 - HEGRA GeV/TeV Observations
  51. GRB010222: Chandra X-ray Observatory Observation
  52. GRB010222: Sub-millimeter vanishing act
  53. GRB010222 - Optical observation
  54. GRB 010222, Optical Observations
  55. GRB010222 - Optical observation
  56. GRB 010222: High-Resolution Keck Spectroscopy
  57. GRB 010214, I-band data
  58. GRB 010222
  59. GRB010222 further R-band photometry
  60. GRB010222: R-band data
  61. GRB 010222: Keck Spectroscopy
  62. GRB010214, field photometry
  63. GRB010222, field photometry
  64. GRB010222 further R-band photometry
  65. GRB010222, possible increase of optical decay slope
  66. GRB 010222 Kyoto optical observation
  67. GRB010222 R-BAND OBSERVATION
  68. GRB010214 follow-up from Hanle
  69. GRB 010222: Near-IR Observations
  70. GRB 010222: Optical Observations
  71. GRB010222: Optical decay slope
  72. GRB 010214, Optical Observations
  73. GRB010222, radio observations
  74. GRB010222, optical observations
  75. GRB010222: BeppoSAX/NFI Observations
  76. GRB010214B,Gamma Ray Observations
  77. GRB 010220, simultaneous optical observations
  78. GRB010220: BeppoSAX WFC and GRBM preliminary data
  79. GRB010214, candidate optical afterglow
  80. GRB010214, optical observations
  81. GRB010214: BeppoSAX WFC and GRBM preliminary data
  82. GRB 010214: X-Ray afterglow
  83. GRB 010214 optical observation
  84. GRB010213, Radio Observations
  85. J-Band Observation of GRB 010214.
  86. GRB010213, Near-IR observations
  87. Possible InfraRed Transient of GRB 010214.
  88. GRB 010214, optical observations
  89. GRB010213 detected by HETE
  90. IPN Status Report
  91. HETE Status
  92. IPN/RXTE TRIANGULATION OF GRB010126
  93. GRB010126 Optical Observations
  94. IPN TRIANGULATION OF GRB010126
  95. Optical Observations of GRB 001018 at Keck
  96. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  97. Optical observations of GRB 001018 with JCAM
  98. IPN TRIANGULATION OF GRB010115
  99. IPN TRIANGULATION OF GRB010109
  100. IPN TRIANGULATION OF GRB010109

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