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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"

41195 results found.

  1. GRB 011030 K-band Observations
  2. GRB010921, optical observations
  3. GRB 011030, WSRT radio observations
  4. GRB011030 - further refinement WFC position
  5. GRB 011030, Radio observations
  6. GRB 011030, R-band observations
  7. BeppoSAX ALERT: Possible X-ray rich GRB011030
  8. GRB 010921: Possible supernova component
  9. GRB011019: NEAT Optical Observations
  10. GRB011019: ROTSE-III optical observations
  11. GRB010921, optical observation at early time
  12. GRB011019: Optical observations
  13. GRB011019, optical observations -- correction
  14. GRB011019, optical observations
  15. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  16. GRB010921: Spectroscopy of the Host Galaxy
  17. GRB 010921: The afterglow of HETE #1761
  18. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  19. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  20. GRB010923 as seen by BeppoSAX GRBM
  21. GRB010928(=H1770): Localization of a Long GRB by HETE
  22. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  23. GRB010921, negative optical observations
  24. GRB010921 field photometry
  25. GRB010921 Optical Observations
  26. GRB 010921 DPOSS Images Available
  27. IPN triangulation of GRB010921 (=H1761)
  28. H1761: A Bright GRB Detected by HETE
  29. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  30. HETE Trigger #1760 (GRB 010920B?): a new optical source
  31. HETE Trigger #1759 (GRB 010920?) optical observations
  32. GRB000926, Host Galaxy Observations
  33. GRB001109, Host Galaxy Spectroscopic Observations
  34. Probable SGR or Short Duration GRB Detected by HETE
  35. GRB000926 Host Galaxy Observations
  36. GRB 010222: HST observations -- host galaxy and late-time decay
  37. GCN and HETE status
  38. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  39. GRB 010222 - WHT BVRI images
  40. SGR1900+14 burst seen by HETE: BeppoSAX data
  41. GRB 010629 Optical Observations
  42. GRB010629: Optical Observations
  43. SGR1900+14: High Fluence Burst Localized by HETE
  44. GRB010629, optical observations
  45. IPN triangulation of GRB010629
  46. GRB010629: A Burst Localized by HETE
  47. SGR1900+14: Second Burst Localized by HETE
  48. SGR1900+14: A Burst Localized by HETE
  49. Possible burst from SGR1806-20
  50. IPN detection of SGR1900+14
  51. SGR1806-20: A Second, Intense Burst Localized by HETE
  52. GRB 00630: Host Galaxy
  53. SGR1806-20: Localization by HETE
  54. IPN triangulation of GRB010613
  55. IPN triangulation of GRB010612
  56. IPN triangulation of GRB010612
  57. GRB000301C: Late-time HST/STIS observation
  58. GRB010518: a faint BeppoSAX detection
  59. GRB000418: HST/STIS Second-epoch Observations
  60. X-ray precursors to the large flare from SGR 1900+14
  61. GRB010214, optical observations
  62. SGR 1900+14: No evidence of extended X-ray emission
  63. SGR 1900+14 : RXTE observations
  64. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  65. SGR1900+14
  66. Millimeter observation of SGR 1900+14
  67. SGR 1900+14: Detection of extended X-ray emission
  68. Chandra Observations of SGR 1900+14
  69. SGR 1900+14, Chandra observations
  70. Chandra Observations of SGR 1900+14
  71. SGR1900+14, I-band observations
  72. GRB010412, field photometry
  73. Giant flare from SGR1900+14
  74. GRB 010326b Optical Observations
  75. GRB010412: Optical observations
  76. GRB010412: Optical observations
  77. GRB010412: BeppoSAX GRBM and WFC observations
  78. IPN Triangulation of GRB010412
  79. BeppoSAX GRB: extension of BSAX operations upto April 30, 2002
  80. GRB Observation Report
  81. GRB010324, revised field photometry
  82. REVISED LOCATION OF GRB010326A
  83. GRB 980326: Late-time HST/STIS observations
  84. GRB010324, field photometry
  85. GRB010326B, field photometry
  86. GRB010326, field photometry
  87. GRB010220, field photometry
  88. Further Optical Observations of GRB 010324
  89. GRB010222, CXO X-ray observations
  90. GRB 010326A: Further optical observations
  91. GRB010324: BeppoSAX/GRBM data
  92. GRB 010326B: Optical observations
  93. GRB010324, optical observations
  94. GRB010326B: Localization by HETE (2nd GRB for this date)
  95. GRB 010326: Optical observations
  96. GRB 010326 optical observations
  97. GRB010326: Refined Localization by HETE
  98. GRB010326: Localization by HETE
  99. Duration, ECT, peak flux and fluence of GRB010324
  100. Optical Observations of GRB 010324

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