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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"

25883 results found.

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

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