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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. GRB010629, optical observations
  2. IPN triangulation of GRB010629
  3. GRB010629: A Burst Localized by HETE
  4. SGR1900+14: Second Burst Localized by HETE
  5. SGR1900+14: A Burst Localized by HETE
  6. Possible burst from SGR1806-20
  7. IPN detection of SGR1900+14
  8. SGR1806-20: A Second, Intense Burst Localized by HETE
  9. GRB 00630: Host Galaxy
  10. SGR1806-20: Localization by HETE
  11. IPN triangulation of GRB010613
  12. IPN triangulation of GRB010612
  13. IPN triangulation of GRB010612
  14. HETE Fully-Automated GCN Notices
  15. GRB000301C: Late-time HST/STIS observation
  16. GRB010518: a faint BeppoSAX detection
  17. GRB000418: HST/STIS Second-epoch Observations
  18. X-ray precursors to the large flare from SGR 1900+14
  19. GRB010214, optical observations
  20. GRB010427, Gamma Ray Observations
  21. SGR 1900+14: No evidence of extended X-ray emission
  22. SGR 1900+14 : RXTE observations
  23. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  24. SGR1900+14 - correction
  25. SGR1900+14
  26. SGR 1900+14: Correction to GCN 1049
  27. GRB 010222 /corrections to VBT data
  28. Millimeter observation of SGR 1900+14
  29. SGR 1900+14: Detection of extended X-ray emission
  30. Chandra Observations of SGR 1900+14
  31. SGR 1900+14, Chandra observations
  32. Chandra Observations of SGR 1900+14
  33. Possible precursor to the SGR1900+14 giant burst
  34. SGR1900+14, I-band observations
  35. IPN Triangulation of the Giant Flare from SGR1900+14
  36. GRB010412, field photometry
  37. Giant flare from SGR1900+14
  38. GRB 010326b Optical Observations
  39. GRB010412: Optical observations
  40. GRB010412: Optical observations
  41. GRB010412: BeppoSAX GRBM and WFC observations
  42. IPN Triangulation of GRB010412
  43. GRB010412: refined positions from BeppoSAX
  44. BeppoSAX GRB: extension of BSAX operations upto April 30, 2002
  45. BeppoSAX GRB ALERT: GRB010412
  46. GRB Observation Report
  47. GRB010324, revised field photometry
  48. REVISED LOCATION OF GRB010326A
  49. GRB 980326: Late-time HST/STIS observations
  50. GRB010324, field photometry
  51. GRB010326B, field photometry
  52. GRB010326, field photometry
  53. GRB010220, field photometry
  54. Further Optical Observations of GRB 010324
  55. GRB010222, CXO X-ray observations
  56. GRB 010326A: Further optical observations
  57. GRB010324: BeppoSAX/GRBM data
  58. GRB 010326B: Optical observations
  59. GRB010324, optical observations
  60. GRB010326B: Localization by HETE (2nd GRB for this date)
  61. GRB 010326: Optical observations
  62. GRB 010326 optical observations
  63. GRB010326: Refined Localization by HETE
  64. GRB010326: Localization by HETE
  65. Duration, ECT, peak flux and fluence of GRB010324
  66. Optical Observations of GRB 010324
  67. IPN TRIANGULATION OF GRB010324
  68. GRB990705, VLT-FORS1 observations of the host galaxy
  69. GRB010222, late-time optical observation
  70. Support extension to the BeppoSAX mission
  71. GRB 010222 - HEGRA GeV/TeV Observations
  72. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  73. GRB010222: Chandra X-ray Observatory Observation
  74. GRB010222: Sub-millimeter vanishing act
  75. GRB010222 - Optical observation
  76. GRB 010222, Optical Observations
  77. GRB010220 optical obsercations
  78. GRB010222 - Optical observation
  79. GRB 010222: High-Resolution Keck Spectroscopy
  80. GRB010222: Optical observation and decay
  81. GRB 010214, I-band data
  82. Sub-millimeter Excess/GRB 010222
  83. GRB 010222
  84. GRB 010222 HST/Chandra TOO
  85. GRB 010222
  86. GRB010222 further R-band photometry
  87. GRB010222: R-band data
  88. GRB010222 Optical observations
  89. GRB 010222: Keck Spectroscopy
  90. GRB010214, field photometry
  91. GRB010222, field photometry
  92. GRB010222 further R-band photometry
  93. GRB010222, possible increase of optical decay slope
  94. GRB 010222 Kyoto optical observation
  95. GRB010222: fading behavior
  96. GRB 010222 BV optical observations
  97. GRB010220, Optical Observations
  98. GRB010222 R-BAND OBSERVATION
  99. GRB 010220: Near-IR Observations
  100. GRB010214 follow-up from Hanle

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