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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"

42561 results found.

  1. GRB 011030 I-band Observation
  2. The X-ray Flash 011030 ('GRB 011030')
  3. Non-triggered burst 011030 ("GRB 011030")
  4. The Radio Afterglow from the X-ray Rich GRB 011030
  5. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  6. GRB 970828: HST Observations of the Host Galaxy
  7. GRB 000131: HST Detection of the Host Galaxy
  8. GRB 970828: HST Observations of the Host Galaxy
  9. GRB010921, optical observation
  10. GRB 011019 optical observation
  11. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  12. GRB 011030 I-band Observations
  13. GRB 011030 K-band Observations
  14. GRB010921, optical observations
  15. GRB 011030, WSRT radio observations
  16. GRB011030 - further refinement WFC position
  17. GRB 011030, Radio observations
  18. GRB011030: radio search
  19. GRB 011030, R-band observations
  20. BeppoSAX ALERT: Possible X-ray rich GRB011030
  21. GRB 010921: Possible supernova component
  22. GRB011019: NEAT Optical Observations
  23. GRB011019: ROTSE-III optical observations
  24. GRB010921, optical observation at early time
  25. GRB 010921, I-band observations
  26. GRB011019: Optical observations
  27. GRB011019, optical observations -- correction
  28. GRB011019, optical observations
  29. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  30. GRB010921: Spectroscopy of the Host Galaxy
  31. GRB 010921: The afterglow of HETE #1761
  32. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  33. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  34. GRB010923 as seen by BeppoSAX GRBM
  35. GRB010928(=H1770): Localization of a Long GRB by HETE
  36. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  37. GRB010921, negative optical observations
  38. GRB010921 field photometry
  39. GRB 010921 DPOSS Images Available
  40. IPN triangulation of GRB010921 (=H1761)
  41. H1761: A Bright GRB Detected by HETE
  42. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  43. HETE Trigger #1760 (GRB 010920B?): a new optical source
  44. HETE Trigger #1759 (GRB 010920?) optical observations
  45. GRB001109, Host Galaxy Astrometry
  46. GRB000926, Host Galaxy Observations
  47. GRB001109, Host Galaxy Spectroscopic Observations
  48. Probable SGR or Short Duration GRB Detected by HETE
  49. GRB000926 Host Galaxy Observations
  50. GRB 010222: HST observations -- host galaxy and late-time decay
  51. BeppoSAX/GRBM detection of GRB 010801
  52. GCN and HETE status
  53. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  54. BeppoSAX/GRBM detection of GRB010728
  55. GRB 010222 - WHT BVRI images
  56. SGR1900+14 burst seen by HETE: BeppoSAX data
  57. GRB 010629 Optical Observations
  58. GRB010629: Optical Observations
  59. SGR1900+14: High Fluence Burst Localized by HETE
  60. GRB010629, optical observations
  61. IPN triangulation of GRB010629
  62. GRB010629: A Burst Localized by HETE
  63. SGR1900+14: Second Burst Localized by HETE
  64. SGR1900+14: A Burst Localized by HETE
  65. Possible burst from SGR1806-20
  66. IPN detection of SGR1900+14
  67. SGR1806-20: A Second, Intense Burst Localized by HETE
  68. GRB 00630: Host Galaxy
  69. SGR1806-20: Localization by HETE
  70. IPN triangulation of GRB010613
  71. IPN triangulation of GRB010612
  72. IPN triangulation of GRB010612
  73. HETE Fully-Automated GCN Notices
  74. GRB000301C: Late-time HST/STIS observation
  75. GRB010518: a faint BeppoSAX detection
  76. GRB000418: HST/STIS Second-epoch Observations
  77. X-ray precursors to the large flare from SGR 1900+14
  78. GRB010214, optical observations
  79. GRB010427, Gamma Ray Observations
  80. SGR 1900+14: No evidence of extended X-ray emission
  81. SGR 1900+14 : RXTE observations
  82. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  83. SGR1900+14
  84. SGR 1900+14: Detection of extended X-ray emission
  85. Chandra Observations of SGR 1900+14
  86. SGR 1900+14, Chandra observations
  87. Chandra Observations of SGR 1900+14
  88. Possible precursor to the SGR1900+14 giant burst
  89. SGR1900+14, I-band observations
  90. IPN Triangulation of the Giant Flare from SGR1900+14
  91. GRB010412, field photometry
  92. Giant flare from SGR1900+14
  93. GRB 010326b Optical Observations
  94. GRB010412: Optical observations
  95. GRB010412: Optical observations
  96. GRB010412: BeppoSAX GRBM and WFC observations
  97. IPN Triangulation of GRB010412
  98. BeppoSAX GRB ALERT: GRB010412
  99. GRB Observation Report
  100. GRB010324, revised field photometry

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