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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').
  1. GRB 010921: The afterglow of HETE #1761
  2. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  3. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  4. GRB010923 as seen by BeppoSAX GRBM
  5. GRB010928(=H1770): Localization of a Long GRB by HETE
  6. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  7. GRB010921, negative optical observations
  8. GRB010921 field photometry
  9. GRB010921 Optical Observations
  10. GRB 010921 DPOSS Images Available
  11. IPN triangulation of GRB010921 (=H1761)
  12. H1761: A Bright GRB Detected by HETE
  13. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  14. HETE Trigger #1760 (GRB 010920B?): a new optical source
  15. HETE Trigger #1759 (GRB 010920?) optical observations
  16. GRB001109, Host Galaxy Astrometry
  17. GRB000926, Host Galaxy Observations
  18. GRB001109, Host Galaxy Spectroscopic Observations
  19. Probable SGR or Short Duration GRB Detected by HETE
  20. GRB000926 Host Galaxy Observations
  21. GRB 010222: HST observations -- host galaxy and late-time decay
  22. BeppoSAX/GRBM detection of GRB 010801
  23. GCN and HETE status
  24. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  25. BeppoSAX/GRBM detection of GRB010728
  26. GRB 010222 - WHT BVRI images
  27. SGR1900+14 burst seen by HETE: BeppoSAX data
  28. GRB 010629 Optical Observations
  29. GRB010629: Optical Observations
  30. SGR1900+14: High Fluence Burst Localized by HETE
  31. GRB010629, optical observations
  32. IPN triangulation of GRB010629
  33. GRB010629: A Burst Localized by HETE
  34. SGR1900+14: Second Burst Localized by HETE
  35. SGR1900+14: A Burst Localized by HETE
  36. Possible burst from SGR1806-20
  37. IPN detection of SGR1900+14
  38. SGR1806-20: A Second, Intense Burst Localized by HETE
  39. GRB 00630: Host Galaxy
  40. SGR1806-20: Localization by HETE
  41. IPN triangulation of GRB010613
  42. IPN triangulation of GRB010612
  43. IPN triangulation of GRB010612
  44. HETE Fully-Automated GCN Notices
  45. GRB000301C: Late-time HST/STIS observation
  46. GRB010518: a faint BeppoSAX detection
  47. GRB000418: HST/STIS Second-epoch Observations
  48. X-ray precursors to the large flare from SGR 1900+14
  49. GRB010214, optical observations
  50. GRB010427, Gamma Ray Observations
  51. SGR 1900+14: No evidence of extended X-ray emission
  52. SGR 1900+14 : RXTE observations
  53. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  54. SGR1900+14 - correction
  55. SGR1900+14
  56. SGR 1900+14: Correction to GCN 1049
  57. GRB 010222 /corrections to VBT data
  58. Millimeter observation of SGR 1900+14
  59. SGR 1900+14: Detection of extended X-ray emission
  60. Chandra Observations of SGR 1900+14
  61. SGR 1900+14, Chandra observations
  62. Chandra Observations of SGR 1900+14
  63. Possible precursor to the SGR1900+14 giant burst
  64. SGR1900+14, I-band observations
  65. IPN Triangulation of the Giant Flare from SGR1900+14
  66. GRB010412, field photometry
  67. Giant flare from SGR1900+14
  68. GRB 010326b Optical Observations
  69. GRB010412: Optical observations
  70. GRB010412: Optical observations
  71. GRB010412: BeppoSAX GRBM and WFC observations
  72. IPN Triangulation of GRB010412
  73. GRB010412: refined positions from BeppoSAX
  74. BeppoSAX GRB: extension of BSAX operations upto April 30, 2002
  75. BeppoSAX GRB ALERT: GRB010412
  76. GRB Observation Report
  77. GRB010324, revised field photometry
  78. REVISED LOCATION OF GRB010326A
  79. GRB 980326: Late-time HST/STIS observations
  80. GRB010324, field photometry
  81. GRB010326B, field photometry
  82. GRB010326, field photometry
  83. GRB010220, field photometry
  84. Further Optical Observations of GRB 010324
  85. GRB010222, CXO X-ray observations
  86. GRB 010326A: Further optical observations
  87. GRB010324: BeppoSAX/GRBM data
  88. GRB 010326B: Optical observations
  89. GRB010324, optical observations
  90. GRB010326B: Localization by HETE (2nd GRB for this date)
  91. GRB 010326: Optical observations
  92. GRB 010326 optical observations
  93. GRB010326: Refined Localization by HETE
  94. GRB010326: Localization by HETE
  95. Duration, ECT, peak flux and fluence of GRB010324
  96. Optical Observations of GRB 010324
  97. IPN TRIANGULATION OF GRB010324
  98. GRB990705, VLT-FORS1 observations of the host galaxy
  99. GRB010222, late-time optical observation
  100. Support extension to the BeppoSAX mission

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