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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"

23406 results found.

  1. GRB 011121: Radio Observations
  2. GRB 011121 J-Band Astrometry
  3. GRB 011121: Detection of Bright IR Counterpart
  4. GRB011121: possible redshift, continued decay
  5. IPN triangulation of GRB011121
  6. GRB 011030: TNG K-band observation
  7. XRF011030: J and K band observations
  8. XRF011030: Chandra Observations
  9. GRB011030: Z-band observations
  10. The X-ray Flash 011030 ('GRB 011030')
  11. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  12. GRB 970828: HST Observations of the Host Galaxy
  13. GRB 000131: HST Detection of the Host Galaxy
  14. GRB 970828: HST Observations of the Host Galaxy
  15. GRB011019: Subaru Optical Observations
  16. GRB011030 - further refinement WFC position
  17. GRB 011030, Radio observations
  18. GRB011030: radio search
  19. X-ray rich GRB011030: BeppoSAX refined positions
  20. GRB 010921: Possible supernova component
  21. GRB010921, optical observation at early time
  22. GRB 010921, I-band observations
  23. GRB011019, optical observations
  24. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  25. GRB 010921: The afterglow of HETE #1761
  26. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  27. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  28. GRB010928(=H1770): Localization of a Long GRB by HETE
  29. GRB010921, negative optical observations
  30. GRB010921 field photometry
  31. GRB010921 Optical Observations
  32. IPN triangulation of GRB010921 (=H1761)
  33. H1761: A Bright GRB Detected by HETE
  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. GCN and HETE status
  39. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  40. GRB 010222 - WHT BVRI images
  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. SGR1806-20: A Second, Intense Burst Localized by HETE
  50. SGR1806-20: Localization by HETE
  51. IPN triangulation of GRB010613
  52. IPN triangulation of GRB010612
  53. HETE Fully-Automated GCN Notices
  54. GRB000301C: Late-time HST/STIS observation
  55. GRB010518: a faint BeppoSAX detection
  56. GRB000418: HST/STIS Second-epoch Observations
  57. X-ray precursors to the large flare from SGR 1900+14
  58. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  59. Millimeter observation of SGR 1900+14
  60. SGR 1900+14: Detection of extended X-ray emission
  61. SGR 1900+14, Chandra observations
  62. SGR1900+14, I-band observations
  63. GRB010412, field photometry
  64. Giant flare from SGR1900+14
  65. GRB 010326b Optical Observations
  66. GRB010412: BeppoSAX GRBM and WFC observations
  67. IPN Triangulation of GRB010412
  68. GRB Observation Report
  69. GRB010324, revised field photometry
  70. REVISED LOCATION OF GRB010326A
  71. GRB 980326: Late-time HST/STIS observations
  72. GRB010324, field photometry
  73. GRB010326B, field photometry
  74. GRB010326, field photometry
  75. GRB010220, field photometry
  76. Further Optical Observations of GRB 010324
  77. GRB010222, CXO X-ray observations
  78. GRB010324, optical observations
  79. GRB010326B: Localization by HETE (2nd GRB for this date)
  80. GRB 010326 optical observations
  81. GRB010326: Refined Localization by HETE
  82. GRB010326: Localization by HETE
  83. Optical Observations of GRB 010324
  84. GRB990705, VLT-FORS1 observations of the host galaxy
  85. GRB010222, late-time optical observation
  86. Support extension to the BeppoSAX mission
  87. GRB 010222, Optical Observations
  88. GRB010220 optical obsercations
  89. GRB 010222: High-Resolution Keck Spectroscopy
  90. GRB 010214, I-band data
  91. GRB 010222
  92. GRB010222 further R-band photometry
  93. GRB 010222: Keck Spectroscopy
  94. GRB010214, field photometry
  95. GRB010222, field photometry
  96. GRB010222 further R-band photometry
  97. GRB 010222 Kyoto optical observation
  98. GRB010222 R-BAND OBSERVATION
  99. GRB 010220: Near-IR Observations
  100. GRB010214 follow-up from Hanle

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