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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"

26082 results found.

  1. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  2. GRB 010921: The afterglow of HETE #1761
  3. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  4. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  5. GRB010923 as seen by BeppoSAX GRBM
  6. GRB010928(=H1770): Localization of a Long GRB by HETE
  7. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  8. GRB010921, negative optical observations
  9. GRB010921 field photometry
  10. H1761: A Bright GRB Detected by HETE
  11. GRB000926, Host Galaxy Observations
  12. GRB001109, Host Galaxy Spectroscopic Observations
  13. Probable SGR or Short Duration GRB Detected by HETE
  14. GCN and HETE status
  15. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  16. GRB 010222 - WHT BVRI images
  17. SGR1900+14 burst seen by HETE: BeppoSAX data
  18. GRB 010629 Optical Observations
  19. SGR1900+14: High Fluence Burst Localized by HETE
  20. GRB010629, optical observations
  21. GRB010629: A Burst Localized by HETE
  22. SGR1900+14: Second Burst Localized by HETE
  23. SGR1900+14: A Burst Localized by HETE
  24. SGR1806-20: A Second, Intense Burst Localized by HETE
  25. SGR1806-20: Localization by HETE
  26. HETE Fully-Automated GCN Notices
  27. GRB000301C: Late-time HST/STIS observation
  28. GRB010518: a faint BeppoSAX detection
  29. GRB000418: HST/STIS Second-epoch Observations
  30. X-ray precursors to the large flare from SGR 1900+14
  31. GRB010427, Gamma Ray Observations
  32. SGR 1900+14: No evidence of extended X-ray emission
  33. SGR 1900+14 : RXTE observations
  34. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  35. SGR 1900+14: Correction to GCN 1049
  36. GRB 010222 /corrections to VBT data
  37. Millimeter observation of SGR 1900+14
  38. SGR 1900+14: Detection of extended X-ray emission
  39. SGR 1900+14, Chandra observations
  40. SGR1900+14, I-band observations
  41. GRB010412, field photometry
  42. Giant flare from SGR1900+14
  43. GRB 010326b Optical Observations
  44. GRB010412: BeppoSAX GRBM and WFC observations
  45. GRB010324, revised field photometry
  46. REVISED LOCATION OF GRB010326A
  47. GRB 980326: Late-time HST/STIS observations
  48. GRB010324, field photometry
  49. GRB010326B, field photometry
  50. GRB010326, field photometry
  51. GRB010220, field photometry
  52. Further Optical Observations of GRB 010324
  53. GRB010222, CXO X-ray observations
  54. GRB010324, optical observations
  55. GRB010326B: Localization by HETE (2nd GRB for this date)
  56. GRB 010326 optical observations
  57. GRB010326: Refined Localization by HETE
  58. GRB010326: Localization by HETE
  59. Optical Observations of GRB 010324
  60. GRB010222, late-time optical observation
  61. Support extension to the BeppoSAX mission
  62. GRB 010222 - HEGRA GeV/TeV Observations
  63. GRB010222: Chandra X-ray Observatory Observation
  64. GRB010222: Sub-millimeter vanishing act
  65. GRB010222 - Optical observation
  66. GRB 010222, Optical Observations
  67. GRB010222 - Optical observation
  68. GRB 010222: High-Resolution Keck Spectroscopy
  69. GRB 010214, I-band data
  70. GRB 010222
  71. GRB010222 further R-band photometry
  72. GRB010222: R-band data
  73. GRB 010222: Keck Spectroscopy
  74. GRB010214, field photometry
  75. GRB010222, field photometry
  76. GRB010222 further R-band photometry
  77. GRB010222, possible increase of optical decay slope
  78. GRB 010222 Kyoto optical observation
  79. GRB010222 R-BAND OBSERVATION
  80. GRB010214 follow-up from Hanle
  81. GRB 010222: Near-IR Observations
  82. GRB 010222: Optical Observations
  83. GRB010222: Optical decay slope
  84. GRB 010214, Optical Observations
  85. GRB010222, radio observations
  86. GRB010222, optical observations
  87. GRB010222: BeppoSAX/NFI Observations
  88. GRB010214B,Gamma Ray Observations
  89. GRB 010220, simultaneous optical observations
  90. GRB010220: BeppoSAX WFC and GRBM preliminary data
  91. GRB010214, candidate optical afterglow
  92. GRB010214, optical observations
  93. GRB010214: BeppoSAX WFC and GRBM preliminary data
  94. GRB 010214: X-Ray afterglow
  95. GRB 010214 optical observation
  96. GRB010213, Radio Observations
  97. J-Band Observation of GRB 010214.
  98. GRB010213, Near-IR observations
  99. Possible InfraRed Transient of GRB 010214.
  100. GRB 010214, optical observations

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