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

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