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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.

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

24794 results found.

  1. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  2. GRB011019: Subaru Optical Observations
  3. GRB 011030 I-band Observations
  4. GRB 011030 K-band Observations
  5. GRB010921, optical observations
  6. GRB011030 - further refinement WFC position
  7. GRB 011030, Radio observations
  8. GRB011030: radio search
  9. GRB 010921: Possible supernova component
  10. GRB010921, optical observation at early time
  11. GRB 010921, I-band observations
  12. GRB011019, optical observations
  13. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  14. GRB 010921: The afterglow of HETE #1761
  15. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  16. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  17. GRB010923 as seen by BeppoSAX GRBM
  18. GRB010928(=H1770): Localization of a Long GRB by HETE
  19. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  20. GRB010921, negative optical observations
  21. GRB010921 field photometry
  22. H1761: A Bright GRB Detected by HETE
  23. GRB000926, Host Galaxy Observations
  24. GRB001109, Host Galaxy Spectroscopic Observations
  25. Probable SGR or Short Duration GRB Detected by HETE
  26. GCN and HETE status
  27. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  28. GRB 010222 - WHT BVRI images
  29. SGR1900+14 burst seen by HETE: BeppoSAX data
  30. GRB 010629 Optical Observations
  31. SGR1900+14: High Fluence Burst Localized by HETE
  32. GRB010629, optical observations
  33. GRB010629: A Burst Localized by HETE
  34. SGR1900+14: Second Burst Localized by HETE
  35. SGR1900+14: A Burst Localized by HETE
  36. SGR1806-20: A Second, Intense Burst Localized by HETE
  37. SGR1806-20: Localization by HETE
  38. HETE Fully-Automated GCN Notices
  39. GRB000301C: Late-time HST/STIS observation
  40. GRB010518: a faint BeppoSAX detection
  41. GRB000418: HST/STIS Second-epoch Observations
  42. X-ray precursors to the large flare from SGR 1900+14
  43. GRB010427, Gamma Ray Observations
  44. SGR 1900+14: No evidence of extended X-ray emission
  45. SGR 1900+14 : RXTE observations
  46. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  47. SGR 1900+14: Correction to GCN 1049
  48. GRB 010222 /corrections to VBT data
  49. Millimeter observation of SGR 1900+14
  50. SGR 1900+14: Detection of extended X-ray emission
  51. SGR 1900+14, Chandra observations
  52. SGR1900+14, I-band observations
  53. GRB010412, field photometry
  54. Giant flare from SGR1900+14
  55. GRB 010326b Optical Observations
  56. GRB010412: BeppoSAX GRBM and WFC observations
  57. GRB010324, revised field photometry
  58. REVISED LOCATION OF GRB010326A
  59. GRB 980326: Late-time HST/STIS observations
  60. GRB010324, field photometry
  61. GRB010326B, field photometry
  62. GRB010326, field photometry
  63. GRB010220, field photometry
  64. Further Optical Observations of GRB 010324
  65. GRB010222, CXO X-ray observations
  66. GRB010324, optical observations
  67. GRB010326B: Localization by HETE (2nd GRB for this date)
  68. GRB 010326 optical observations
  69. GRB010326: Refined Localization by HETE
  70. GRB010326: Localization by HETE
  71. Optical Observations of GRB 010324
  72. GRB010222, late-time optical observation
  73. Support extension to the BeppoSAX mission
  74. GRB 010222 - HEGRA GeV/TeV Observations
  75. GRB010222: Chandra X-ray Observatory Observation
  76. GRB010222: Sub-millimeter vanishing act
  77. GRB010222 - Optical observation
  78. GRB 010222, Optical Observations
  79. GRB010222 - Optical observation
  80. GRB 010222: High-Resolution Keck Spectroscopy
  81. GRB 010214, I-band data
  82. GRB 010222
  83. GRB010222 further R-band photometry
  84. GRB010222: R-band data
  85. GRB 010222: Keck Spectroscopy
  86. GRB010214, field photometry
  87. GRB010222, field photometry
  88. GRB010222 further R-band photometry
  89. GRB010222, possible increase of optical decay slope
  90. GRB 010222 Kyoto optical observation
  91. GRB010222 R-BAND OBSERVATION
  92. GRB010214 follow-up from Hanle
  93. GRB 010222: Near-IR Observations
  94. GRB 010222: Optical Observations
  95. GRB010222: Optical decay slope
  96. GRB 010214, Optical Observations
  97. GRB010222, radio observations
  98. GRB010222, optical observations
  99. GRB010222: BeppoSAX/NFI Observations
  100. GRB010214B,Gamma Ray Observations

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