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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"

28081 results found.

  1. GRB 010921: The afterglow of HETE #1761
  2. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  3. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  4. GRB010923 as seen by BeppoSAX GRBM
  5. GRB010928(=H1770): Localization of a Long GRB by HETE
  6. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  7. GRB010921, negative optical observations
  8. GRB010921 field photometry
  9. H1761: A Bright GRB Detected by HETE
  10. GRB000926, Host Galaxy Observations
  11. GRB001109, Host Galaxy Spectroscopic Observations
  12. Probable SGR or Short Duration GRB Detected by HETE
  13. GCN and HETE status
  14. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  15. GRB 010222 - WHT BVRI images
  16. SGR1900+14 burst seen by HETE: BeppoSAX data
  17. GRB 010629 Optical Observations
  18. SGR1900+14: High Fluence Burst Localized by HETE
  19. GRB010629, optical observations
  20. GRB010629: A Burst Localized by HETE
  21. SGR1900+14: Second Burst Localized by HETE
  22. SGR1900+14: A Burst Localized by HETE
  23. SGR1806-20: A Second, Intense Burst Localized by HETE
  24. SGR1806-20: Localization by HETE
  25. HETE Fully-Automated GCN Notices
  26. GRB000301C: Late-time HST/STIS observation
  27. GRB010518: a faint BeppoSAX detection
  28. GRB000418: HST/STIS Second-epoch Observations
  29. X-ray precursors to the large flare from SGR 1900+14
  30. GRB010427, Gamma Ray Observations
  31. SGR 1900+14: No evidence of extended X-ray emission
  32. SGR 1900+14 : RXTE observations
  33. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  34. SGR 1900+14: Correction to GCN 1049
  35. GRB 010222 /corrections to VBT data
  36. Millimeter observation of SGR 1900+14
  37. SGR 1900+14: Detection of extended X-ray emission
  38. SGR 1900+14, Chandra observations
  39. SGR1900+14, I-band observations
  40. GRB010412, field photometry
  41. Giant flare from SGR1900+14
  42. GRB 010326b Optical Observations
  43. GRB010412: BeppoSAX GRBM and WFC observations
  44. GRB010324, revised field photometry
  45. REVISED LOCATION OF GRB010326A
  46. GRB 980326: Late-time HST/STIS observations
  47. GRB010324, field photometry
  48. GRB010326B, field photometry
  49. GRB010326, field photometry
  50. GRB010220, field photometry
  51. Further Optical Observations of GRB 010324
  52. GRB010222, CXO X-ray observations
  53. GRB010324, optical observations
  54. GRB010326B: Localization by HETE (2nd GRB for this date)
  55. GRB 010326 optical observations
  56. GRB010326: Refined Localization by HETE
  57. GRB010326: Localization by HETE
  58. Optical Observations of GRB 010324
  59. GRB010222, late-time optical observation
  60. Support extension to the BeppoSAX mission
  61. GRB 010222 - HEGRA GeV/TeV Observations
  62. GRB010222: Chandra X-ray Observatory Observation
  63. GRB010222: Sub-millimeter vanishing act
  64. GRB010222 - Optical observation
  65. GRB 010222, Optical Observations
  66. GRB010222 - Optical observation
  67. GRB 010222: High-Resolution Keck Spectroscopy
  68. GRB 010214, I-band data
  69. GRB 010222
  70. GRB010222 further R-band photometry
  71. GRB010222: R-band data
  72. GRB 010222: Keck Spectroscopy
  73. GRB010214, field photometry
  74. GRB010222, field photometry
  75. GRB010222 further R-band photometry
  76. GRB010222, possible increase of optical decay slope
  77. GRB 010222 Kyoto optical observation
  78. GRB010222 R-BAND OBSERVATION
  79. GRB010214 follow-up from Hanle
  80. GRB 010222: Near-IR Observations
  81. GRB 010222: Optical Observations
  82. GRB010222: Optical decay slope
  83. GRB 010214, Optical Observations
  84. GRB010222, radio observations
  85. GRB010222, optical observations
  86. GRB010222: BeppoSAX/NFI Observations
  87. GRB010214B,Gamma Ray Observations
  88. GRB 010220, simultaneous optical observations
  89. GRB010220: BeppoSAX WFC and GRBM preliminary data
  90. GRB010214, candidate optical afterglow
  91. GRB010214, optical observations
  92. GRB010214: BeppoSAX WFC and GRBM preliminary data
  93. GRB 010214: X-Ray afterglow
  94. GRB 010214 optical observation
  95. GRB010213, Radio Observations
  96. J-Band Observation of GRB 010214.
  97. GRB010213, Near-IR observations
  98. Possible InfraRed Transient of GRB 010214.
  99. GRB 010214, optical observations
  100. GRB010213 detected by HETE

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