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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').
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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

42199 results found.

  1. GRB 011019 optical observation
  2. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  3. GRB011019: Subaru Optical Observations
  4. GRB 011030 I-band Observations
  5. GRB 011030 K-band Observations
  6. GRB010921, optical observations
  7. GRB 011030, WSRT radio observations
  8. GRB011030 - further refinement WFC position
  9. GRB 011030, Radio observations
  10. GRB 011030, R-band observations
  11. BeppoSAX ALERT: Possible X-ray rich GRB011030
  12. GRB 010921: Possible supernova component
  13. GRB011019: NEAT Optical Observations
  14. GRB011019: ROTSE-III optical observations
  15. GRB010921, optical observation at early time
  16. GRB011019: Optical observations
  17. GRB011019, optical observations -- correction
  18. GRB011019, optical observations
  19. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  20. GRB010921: Spectroscopy of the Host Galaxy
  21. GRB 010921: The afterglow of HETE #1761
  22. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  23. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  24. GRB010923 as seen by BeppoSAX GRBM
  25. GRB010928(=H1770): Localization of a Long GRB by HETE
  26. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  27. GRB010921, negative optical observations
  28. GRB010921 field photometry
  29. GRB010921 Optical Observations
  30. GRB 010921 DPOSS Images Available
  31. IPN triangulation of GRB010921 (=H1761)
  32. H1761: A Bright GRB Detected by HETE
  33. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  34. HETE Trigger #1760 (GRB 010920B?): a new optical source
  35. HETE Trigger #1759 (GRB 010920?) optical observations
  36. GRB000926, Host Galaxy Observations
  37. GRB001109, Host Galaxy Spectroscopic Observations
  38. Probable SGR or Short Duration GRB Detected by HETE
  39. GRB000926 Host Galaxy Observations
  40. GRB 010222: HST observations -- host galaxy and late-time decay
  41. GCN and HETE status
  42. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  43. GRB 010222 - WHT BVRI images
  44. SGR1900+14 burst seen by HETE: BeppoSAX data
  45. GRB 010629 Optical Observations
  46. GRB010629: Optical Observations
  47. SGR1900+14: High Fluence Burst Localized by HETE
  48. GRB010629, optical observations
  49. IPN triangulation of GRB010629
  50. GRB010629: A Burst Localized by HETE
  51. SGR1900+14: Second Burst Localized by HETE
  52. SGR1900+14: A Burst Localized by HETE
  53. Possible burst from SGR1806-20
  54. IPN detection of SGR1900+14
  55. SGR1806-20: A Second, Intense Burst Localized by HETE
  56. GRB 00630: Host Galaxy
  57. SGR1806-20: Localization by HETE
  58. IPN triangulation of GRB010613
  59. IPN triangulation of GRB010612
  60. IPN triangulation of GRB010612
  61. GRB000301C: Late-time HST/STIS observation
  62. GRB010518: a faint BeppoSAX detection
  63. GRB000418: HST/STIS Second-epoch Observations
  64. X-ray precursors to the large flare from SGR 1900+14
  65. GRB010214, optical observations
  66. SGR 1900+14: No evidence of extended X-ray emission
  67. SGR 1900+14 : RXTE observations
  68. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  69. SGR1900+14
  70. Millimeter observation of SGR 1900+14
  71. SGR 1900+14: Detection of extended X-ray emission
  72. Chandra Observations of SGR 1900+14
  73. SGR 1900+14, Chandra observations
  74. Chandra Observations of SGR 1900+14
  75. SGR1900+14, I-band observations
  76. GRB010412, field photometry
  77. Giant flare from SGR1900+14
  78. GRB 010326b Optical Observations
  79. GRB010412: Optical observations
  80. GRB010412: Optical observations
  81. GRB010412: BeppoSAX GRBM and WFC observations
  82. IPN Triangulation of GRB010412
  83. BeppoSAX GRB: extension of BSAX operations upto April 30, 2002
  84. GRB Observation Report
  85. GRB010324, revised field photometry
  86. REVISED LOCATION OF GRB010326A
  87. GRB 980326: Late-time HST/STIS observations
  88. GRB010324, field photometry
  89. GRB010326B, field photometry
  90. GRB010326, field photometry
  91. GRB010220, field photometry
  92. Further Optical Observations of GRB 010324
  93. GRB010222, CXO X-ray observations
  94. GRB 010326A: Further optical observations
  95. GRB010324: BeppoSAX/GRBM data
  96. GRB 010326B: Optical observations
  97. GRB010324, optical observations
  98. GRB010326B: Localization by HETE (2nd GRB for this date)
  99. GRB 010326: Optical observations
  100. GRB 010326 optical observations

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