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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"

24784 results found.

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

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