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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"

21681 results found.

  1. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  2. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  3. GRB010928(=H1770): Localization of a Long GRB by HETE
  4. GRB010921, negative optical observations
  5. GRB010921 field photometry
  6. GRB010921 Optical Observations
  7. IPN triangulation of GRB010921 (=H1761)
  8. H1761: A Bright GRB Detected by HETE
  9. HETE Trigger #1760 (GRB 010920B?): a new optical source
  10. HETE Trigger #1759 (GRB 010920?) optical observations
  11. GRB000926, Host Galaxy Observations
  12. GRB001109, Host Galaxy Spectroscopic Observations
  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. GRB 010629 Optical Observations
  17. GRB010629: Optical Observations
  18. SGR1900+14: High Fluence Burst Localized by HETE
  19. GRB010629, optical observations
  20. IPN triangulation of GRB010629
  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. IPN triangulation of GRB010613
  27. IPN triangulation of GRB010612
  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. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  34. Millimeter observation of SGR 1900+14
  35. SGR 1900+14: Detection of extended X-ray emission
  36. SGR 1900+14, Chandra observations
  37. SGR1900+14, I-band observations
  38. GRB010412, field photometry
  39. Giant flare from SGR1900+14
  40. GRB 010326b Optical Observations
  41. GRB010412: BeppoSAX GRBM and WFC observations
  42. IPN Triangulation of GRB010412
  43. GRB Observation Report
  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. GRB990705, VLT-FORS1 observations of the host galaxy
  60. GRB010222, late-time optical observation
  61. Support extension to the BeppoSAX mission
  62. GRB 010222, Optical Observations
  63. GRB010220 optical obsercations
  64. GRB 010222: High-Resolution Keck Spectroscopy
  65. GRB 010214, I-band data
  66. GRB 010222
  67. GRB010222 further R-band photometry
  68. GRB 010222: Keck Spectroscopy
  69. GRB010214, field photometry
  70. GRB010222, field photometry
  71. GRB010222 further R-band photometry
  72. GRB 010222 Kyoto optical observation
  73. GRB010222 R-BAND OBSERVATION
  74. GRB 010220: Near-IR Observations
  75. GRB010214 follow-up from Hanle
  76. GRB 010222: Near-IR Observations
  77. GRB 010222: Optical Observations
  78. GRB010222, radio observations
  79. GRB010222, optical observations
  80. Redshift of the Optical Transient of GRB010222
  81. GRB010220, Radio and Optical Observations
  82. GRB 010220, simultaneous optical observations
  83. GRB010220: BeppoSAX WFC and GRBM preliminary data
  84. GRB010214, candidate optical afterglow
  85. GRB010214, optical observations
  86. GRB010214: BeppoSAX WFC and GRBM preliminary data
  87. GRB 010214: X-Ray afterglow
  88. GRB 010214 optical observation
  89. J-Band Observation of GRB 010214.
  90. GRB010213, Near-IR observations
  91. Possible InfraRed Transient of GRB 010214.
  92. GRB 010214, optical observations
  93. GRB010213 detected by HETE
  94. GRB010214 refined WFC position
  95. IPN Status Report
  96. HETE Status
  97. IPN/RXTE TRIANGULATION OF GRB010126
  98. GRB010126, TNG R-band observations
  99. IPN TRIANGULATION OF GRB010126
  100. Optical Observations of GRB 001018 at Keck

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