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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"
  1. Probable SGR or Short Duration GRB Detected by HETE
  2. GRB000926 Host Galaxy Observations
  3. GRB 010222: HST observations -- host galaxy and late-time decay
  4. BeppoSAX/GRBM detection of GRB 010801
  5. GCN and HETE status
  6. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  7. BeppoSAX/GRBM detection of GRB010728
  8. GRB 010222 - WHT BVRI images
  9. SGR1900+14 burst seen by HETE: BeppoSAX data
  10. GRB 010629 Optical Observations
  11. GRB010629: Optical Observations
  12. SGR1900+14: High Fluence Burst Localized by HETE
  13. GRB010629, optical observations
  14. IPN triangulation of GRB010629
  15. GRB010629: A Burst Localized by HETE
  16. SGR1900+14: Second Burst Localized by HETE
  17. SGR1900+14: A Burst Localized by HETE
  18. Possible burst from SGR1806-20
  19. IPN detection of SGR1900+14
  20. SGR1806-20: A Second, Intense Burst Localized by HETE
  21. GRB 00630: Host Galaxy
  22. SGR1806-20: Localization by HETE
  23. IPN triangulation of GRB010613
  24. IPN triangulation of GRB010612
  25. IPN triangulation of GRB010612
  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. GRB010214, optical observations
  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. SGR1900+14 - correction
  37. SGR1900+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. Chandra Observations of SGR 1900+14
  43. SGR 1900+14, Chandra observations
  44. Chandra Observations of SGR 1900+14
  45. Possible precursor to the SGR1900+14 giant burst
  46. SGR1900+14, I-band observations
  47. IPN Triangulation of the Giant Flare from SGR1900+14
  48. GRB010412, field photometry
  49. Giant flare from SGR1900+14
  50. GRB 010326b Optical Observations
  51. GRB010412: Optical observations
  52. GRB010412: Optical observations
  53. GRB010412: BeppoSAX GRBM and WFC observations
  54. IPN Triangulation of GRB010412
  55. GRB010412: refined positions from BeppoSAX
  56. BeppoSAX GRB: extension of BSAX operations upto April 30, 2002
  57. BeppoSAX GRB ALERT: GRB010412
  58. GRB Observation Report
  59. GRB010324, revised field photometry
  60. REVISED LOCATION OF GRB010326A
  61. GRB 980326: Late-time HST/STIS observations
  62. GRB010324, field photometry
  63. GRB010326B, field photometry
  64. GRB010326, field photometry
  65. GRB010220, field photometry
  66. Further Optical Observations of GRB 010324
  67. GRB010222, CXO X-ray observations
  68. GRB 010326A: Further optical observations
  69. GRB010324: BeppoSAX/GRBM data
  70. GRB 010326B: Optical observations
  71. GRB010324, optical observations
  72. GRB010326B: Localization by HETE (2nd GRB for this date)
  73. GRB 010326: Optical observations
  74. GRB 010326 optical observations
  75. GRB010326: Refined Localization by HETE
  76. GRB010326: Localization by HETE
  77. Duration, ECT, peak flux and fluence of GRB010324
  78. Optical Observations of GRB 010324
  79. IPN TRIANGULATION OF GRB010324
  80. GRB990705, VLT-FORS1 observations of the host galaxy
  81. GRB010222, late-time optical observation
  82. Support extension to the BeppoSAX mission
  83. GRB 010222 - HEGRA GeV/TeV Observations
  84. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  85. GRB010222: Chandra X-ray Observatory Observation
  86. GRB010222: Sub-millimeter vanishing act
  87. GRB010222 - Optical observation
  88. GRB 010222, Optical Observations
  89. GRB010220 optical obsercations
  90. GRB010222 - Optical observation
  91. GRB 010222: High-Resolution Keck Spectroscopy
  92. GRB010222: Optical observation and decay
  93. GRB 010214, I-band data
  94. Sub-millimeter Excess/GRB 010222
  95. GRB 010222
  96. GRB 010222 HST/Chandra TOO
  97. GRB 010222
  98. GRB010222 further R-band photometry
  99. GRB010222: R-band data
  100. GRB010222 Optical observations

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