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

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