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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"

24874 results found.

  1. GRB010921 field photometry
  2. H1761: A Bright GRB Detected by HETE
  3. GRB000926, Host Galaxy Observations
  4. GRB001109, Host Galaxy Spectroscopic Observations
  5. Probable SGR or Short Duration GRB Detected by HETE
  6. GCN and HETE status
  7. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  8. GRB 010222 - WHT BVRI images
  9. SGR1900+14 burst seen by HETE: BeppoSAX data
  10. GRB 010629 Optical Observations
  11. SGR1900+14: High Fluence Burst Localized by HETE
  12. GRB010629, optical observations
  13. GRB010629: A Burst Localized by HETE
  14. SGR1900+14: Second Burst Localized by HETE
  15. SGR1900+14: A Burst Localized by HETE
  16. SGR1806-20: A Second, Intense Burst Localized by HETE
  17. SGR1806-20: Localization by HETE
  18. HETE Fully-Automated GCN Notices
  19. GRB000301C: Late-time HST/STIS observation
  20. GRB010518: a faint BeppoSAX detection
  21. GRB000418: HST/STIS Second-epoch Observations
  22. X-ray precursors to the large flare from SGR 1900+14
  23. GRB010427, Gamma Ray Observations
  24. SGR 1900+14: No evidence of extended X-ray emission
  25. SGR 1900+14 : RXTE observations
  26. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  27. SGR 1900+14: Correction to GCN 1049
  28. GRB 010222 /corrections to VBT data
  29. Millimeter observation of SGR 1900+14
  30. SGR 1900+14: Detection of extended X-ray emission
  31. SGR 1900+14, Chandra observations
  32. SGR1900+14, I-band observations
  33. GRB010412, field photometry
  34. Giant flare from SGR1900+14
  35. GRB 010326b Optical Observations
  36. GRB010412: BeppoSAX GRBM and WFC observations
  37. GRB010324, revised field photometry
  38. REVISED LOCATION OF GRB010326A
  39. GRB 980326: Late-time HST/STIS observations
  40. GRB010324, field photometry
  41. GRB010326B, field photometry
  42. GRB010326, field photometry
  43. GRB010220, field photometry
  44. Further Optical Observations of GRB 010324
  45. GRB010222, CXO X-ray observations
  46. GRB010324, optical observations
  47. GRB010326B: Localization by HETE (2nd GRB for this date)
  48. GRB 010326 optical observations
  49. GRB010326: Refined Localization by HETE
  50. GRB010326: Localization by HETE
  51. Optical Observations of GRB 010324
  52. GRB010222, late-time optical observation
  53. Support extension to the BeppoSAX mission
  54. GRB 010222 - HEGRA GeV/TeV Observations
  55. GRB010222: Chandra X-ray Observatory Observation
  56. GRB010222: Sub-millimeter vanishing act
  57. GRB010222 - Optical observation
  58. GRB 010222, Optical Observations
  59. GRB010222 - Optical observation
  60. GRB 010222: High-Resolution Keck Spectroscopy
  61. GRB 010214, I-band data
  62. GRB 010222
  63. GRB010222 further R-band photometry
  64. GRB010222: R-band data
  65. GRB 010222: Keck Spectroscopy
  66. GRB010214, field photometry
  67. GRB010222, field photometry
  68. GRB010222 further R-band photometry
  69. GRB010222, possible increase of optical decay slope
  70. GRB 010222 Kyoto optical observation
  71. GRB010222 R-BAND OBSERVATION
  72. GRB010214 follow-up from Hanle
  73. GRB 010222: Near-IR Observations
  74. GRB 010222: Optical Observations
  75. GRB010222: Optical decay slope
  76. GRB 010214, Optical Observations
  77. GRB010222, radio observations
  78. GRB010222, optical observations
  79. GRB010222: BeppoSAX/NFI Observations
  80. GRB010214B,Gamma Ray Observations
  81. GRB 010220, simultaneous optical observations
  82. GRB010220: BeppoSAX WFC and GRBM preliminary data
  83. GRB010214, candidate optical afterglow
  84. GRB010214, optical observations
  85. GRB010214: BeppoSAX WFC and GRBM preliminary data
  86. GRB 010214: X-Ray afterglow
  87. GRB 010214 optical observation
  88. GRB010213, Radio Observations
  89. J-Band Observation of GRB 010214.
  90. GRB010213, Near-IR observations
  91. Possible InfraRed Transient of GRB 010214.
  92. GRB 010214, optical observations
  93. GRB010213 detected by HETE
  94. IPN Status Report
  95. HETE Status
  96. IPN/RXTE TRIANGULATION OF GRB010126
  97. GRB010126 Optical Observations
  98. IPN TRIANGULATION OF GRB010126
  99. Optical Observations of GRB 001018 at Keck
  100. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)

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