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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"

43628 results found.

  1. GCN and HETE status
  2. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  3. BeppoSAX/GRBM detection of GRB010728
  4. GRB 010222 - WHT BVRI images
  5. SGR1900+14 burst seen by HETE: BeppoSAX data
  6. GRB 010629 Optical Observations
  7. GRB010629: Optical Observations
  8. SGR1900+14: High Fluence Burst Localized by HETE
  9. GRB010629, optical observations
  10. IPN triangulation of GRB010629
  11. GRB010629: A Burst Localized by HETE
  12. SGR1900+14: Second Burst Localized by HETE
  13. SGR1900+14: A Burst Localized by HETE
  14. Possible burst from SGR1806-20
  15. IPN detection of SGR1900+14
  16. SGR1806-20: A Second, Intense Burst Localized by HETE
  17. GRB 00630: Host Galaxy
  18. SGR1806-20: Localization by HETE
  19. IPN triangulation of GRB010613
  20. IPN triangulation of GRB010612
  21. IPN triangulation of GRB010612
  22. HETE Fully-Automated GCN Notices
  23. GRB000301C: Late-time HST/STIS observation
  24. GRB010518: a faint BeppoSAX detection
  25. GRB000418: HST/STIS Second-epoch Observations
  26. X-ray precursors to the large flare from SGR 1900+14
  27. GRB010214, optical observations
  28. GRB010427, Gamma Ray Observations
  29. SGR 1900+14: No evidence of extended X-ray emission
  30. SGR 1900+14 : RXTE observations
  31. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  32. SGR1900+14
  33. GRB 010222 /corrections to VBT data
  34. SGR 1900+14: Detection of extended X-ray emission
  35. Chandra Observations of SGR 1900+14
  36. SGR 1900+14, Chandra observations
  37. Chandra Observations of SGR 1900+14
  38. Possible precursor to the SGR1900+14 giant burst
  39. SGR1900+14, I-band observations
  40. IPN Triangulation of the Giant Flare from SGR1900+14
  41. GRB010412, field photometry
  42. Giant flare from SGR1900+14
  43. GRB 010326b Optical Observations
  44. GRB010412: Optical observations
  45. GRB010412: BeppoSAX GRBM and WFC observations
  46. IPN Triangulation of GRB010412
  47. GRB010412: refined positions from BeppoSAX
  48. BeppoSAX GRB ALERT: GRB010412
  49. GRB Observation Report
  50. GRB010324, revised field photometry
  51. REVISED LOCATION OF GRB010326A
  52. GRB 980326: Late-time HST/STIS observations
  53. GRB010324, field photometry
  54. GRB010326B, field photometry
  55. GRB010326, field photometry
  56. GRB010220, field photometry
  57. Further Optical Observations of GRB 010324
  58. GRB010222, CXO X-ray observations
  59. GRB 010326A: Further optical observations
  60. GRB010324: BeppoSAX/GRBM data
  61. GRB 010326B: Optical observations
  62. GRB010324, optical observations
  63. GRB010326B: Localization by HETE (2nd GRB for this date)
  64. GRB 010326: Optical observations
  65. GRB 010326 optical observations
  66. GRB010326: Refined Localization by HETE
  67. GRB010326: Localization by HETE
  68. Duration, ECT, peak flux and fluence of GRB010324
  69. Optical Observations of GRB 010324
  70. IPN TRIANGULATION OF GRB010324
  71. GRB990705, VLT-FORS1 observations of the host galaxy
  72. GRB010222, late-time optical observation
  73. Support extension to the BeppoSAX mission
  74. GRB 010222 - HEGRA GeV/TeV Observations
  75. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  76. GRB010222: Chandra X-ray Observatory Observation
  77. GRB010222: Sub-millimeter vanishing act
  78. GRB010222 - Optical observation
  79. GRB 010222, Optical Observations
  80. GRB010220 optical obsercations
  81. GRB010222 - Optical observation
  82. GRB 010222: High-Resolution Keck Spectroscopy
  83. GRB010222: Optical observation and decay
  84. GRB 010214, I-band data
  85. Sub-millimeter Excess/GRB 010222
  86. GRB 010222
  87. GRB 010222 HST/Chandra TOO
  88. GRB010222 further R-band photometry
  89. GRB010222: R-band data
  90. GRB010222 Optical observations
  91. GRB 010222: Keck Spectroscopy
  92. GRB010214, field photometry
  93. GRB010222, field photometry
  94. GRB010222 further R-band photometry
  95. GRB010222, possible increase of optical decay slope
  96. GRB 010222 Kyoto optical observation
  97. GRB010222: fading behavior
  98. GRB 010222 BV optical observations
  99. GRB010222 R-BAND OBSERVATION
  100. GRB 010220: Near-IR Observations

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