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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. Possible burst from SGR1806-20
  2. IPN detection of SGR1900+14
  3. SGR1806-20: A Second, Intense Burst Localized by HETE
  4. GRB 00630: Host Galaxy
  5. SGR1806-20: Localization by HETE
  6. IPN triangulation of GRB010613
  7. IPN triangulation of GRB010612
  8. IPN triangulation of GRB010612
  9. HETE Fully-Automated GCN Notices
  10. GRB000301C: Late-time HST/STIS observation
  11. GRB010518: a faint BeppoSAX detection
  12. GRB000418: HST/STIS Second-epoch Observations
  13. X-ray precursors to the large flare from SGR 1900+14
  14. GRB010214, optical observations
  15. GRB010427, Gamma Ray Observations
  16. SGR 1900+14: No evidence of extended X-ray emission
  17. SGR 1900+14 : RXTE observations
  18. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  19. SGR1900+14 - correction
  20. SGR1900+14
  21. SGR 1900+14: Correction to GCN 1049
  22. GRB 010222 /corrections to VBT data
  23. Millimeter observation of SGR 1900+14
  24. SGR 1900+14: Detection of extended X-ray emission
  25. Chandra Observations of SGR 1900+14
  26. SGR 1900+14, Chandra observations
  27. Chandra Observations of SGR 1900+14
  28. Possible precursor to the SGR1900+14 giant burst
  29. SGR1900+14, I-band observations
  30. IPN Triangulation of the Giant Flare from SGR1900+14
  31. GRB010412, field photometry
  32. Giant flare from SGR1900+14
  33. GRB 010326b Optical Observations
  34. GRB010412: Optical observations
  35. GRB010412: Optical observations
  36. GRB010412: BeppoSAX GRBM and WFC observations
  37. IPN Triangulation of GRB010412
  38. GRB010412: refined positions from BeppoSAX
  39. BeppoSAX GRB: extension of BSAX operations upto April 30, 2002
  40. BeppoSAX GRB ALERT: GRB010412
  41. GRB Observation Report
  42. GRB010324, revised field photometry
  43. REVISED LOCATION OF GRB010326A
  44. GRB 980326: Late-time HST/STIS observations
  45. GRB010324, field photometry
  46. GRB010326B, field photometry
  47. GRB010326, field photometry
  48. GRB010220, field photometry
  49. Further Optical Observations of GRB 010324
  50. GRB010222, CXO X-ray observations
  51. GRB 010326A: Further optical observations
  52. GRB010324: BeppoSAX/GRBM data
  53. GRB 010326B: Optical observations
  54. GRB010324, optical observations
  55. GRB010326B: Localization by HETE (2nd GRB for this date)
  56. GRB 010326: Optical observations
  57. GRB 010326 optical observations
  58. GRB010326: Refined Localization by HETE
  59. GRB010326: Localization by HETE
  60. Duration, ECT, peak flux and fluence of GRB010324
  61. Optical Observations of GRB 010324
  62. IPN TRIANGULATION OF GRB010324
  63. GRB990705, VLT-FORS1 observations of the host galaxy
  64. GRB010222, late-time optical observation
  65. Support extension to the BeppoSAX mission
  66. GRB 010222 - HEGRA GeV/TeV Observations
  67. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  68. GRB010222: Chandra X-ray Observatory Observation
  69. GRB010222: Sub-millimeter vanishing act
  70. GRB010222 - Optical observation
  71. GRB 010222, Optical Observations
  72. GRB010220 optical obsercations
  73. GRB010222 - Optical observation
  74. GRB 010222: High-Resolution Keck Spectroscopy
  75. GRB010222: Optical observation and decay
  76. GRB 010214, I-band data
  77. Sub-millimeter Excess/GRB 010222
  78. GRB 010222
  79. GRB 010222 HST/Chandra TOO
  80. GRB 010222
  81. GRB010222 further R-band photometry
  82. GRB010222: R-band data
  83. GRB010222 Optical observations
  84. GRB 010222: Keck Spectroscopy
  85. GRB010214, field photometry
  86. GRB010222, field photometry
  87. GRB010222 further R-band photometry
  88. GRB010222, possible increase of optical decay slope
  89. GRB 010222 Kyoto optical observation
  90. GRB010222: fading behavior
  91. GRB 010222 BV optical observations
  92. GRB010220, Optical Observations
  93. GRB010222 R-BAND OBSERVATION
  94. GRB 010220: Near-IR Observations
  95. GRB010214 follow-up from Hanle
  96. GRB 010222: Near-IR Observations
  97. GRB 010222: Optical Observations
  98. GRB 010222, Decay Slope Confirmed
  99. GRB010222: Another absorption line system
  100. GRB010222: Optical decay slope

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