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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"

24785 results found.

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

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