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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"

20358 results found.

  1. GRB011130 (XRF011130) Chandra Observations
  2. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  3. GRB 011130: Magellan spectroscopy
  4. Sub-mm and Centimeter Detections of the Host Galaxy of GRB000418
  5. GRB 011130, K band observations
  6. GRB011130, optical observations
  7. GRB011130 (XRF011130) SDSS PT i-band observations
  8. XRF011130: Infrared Observations
  9. GRB011130 (=XRF011130): Revised Localization of an X-ray
  10. GRB 011121
  11. GRB 011121: J-band observations
  12. GRB 011121: NIR observations, host galaxy?
  13. GRB010921 - Milagro GeV/TeV Observations
  14. GRB 011121: HST Scheduled
  15. GRB011121: UBRI Observations
  16. GRB011121
  17. GRB 011121 J-Band Astrometry
  18. GRB 011121: Detection of Bright IR Counterpart
  19. GRB011121: possible redshift, continued decay
  20. GRB 011030: TNG K-band observation
  21. XRF011030: J and K band observations
  22. XRF011030: Chandra Observations
  23. GRB011030: Z-band observations
  24. The X-ray Flash 011030 ('GRB 011030')
  25. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  26. GRB 970828: HST Observations of the Host Galaxy
  27. GRB 000131: HST Detection of the Host Galaxy
  28. GRB 970828: HST Observations of the Host Galaxy
  29. GRB011019: Subaru Optical Observations
  30. GRB011030 - further refinement WFC position
  31. GRB011030: radio search
  32. GRB 010921: Possible supernova component
  33. GRB010921, optical observation at early time
  34. GRB 010921, I-band observations
  35. GRB011019, optical observations
  36. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  37. GRB010921: Spectroscopy of the Host Galaxy
  38. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  39. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  40. GRB010923 as seen by BeppoSAX GRBM
  41. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  42. GRB010921, negative optical observations
  43. GRB010921 field photometry
  44. GRB010921 Optical Observations
  45. HETE Trigger #1760 (GRB 010920B?): a new optical source
  46. GRB000926, Host Galaxy Observations
  47. GRB001109, Host Galaxy Spectroscopic Observations
  48. GRB 010222: HST observations -- host galaxy and late-time decay
  49. BeppoSAX/GRBM detection of GRB 010801
  50. GCN and HETE status
  51. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  52. GRB 010222 - WHT BVRI images
  53. GRB 010629 Optical Observations
  54. GRB010629: Optical Observations
  55. SGR1900+14: High Fluence Burst Localized by HETE
  56. GRB010629, optical observations
  57. GRB010629: A Burst Localized by HETE
  58. SGR1900+14: Second Burst Localized by HETE
  59. SGR1900+14: A Burst Localized by HETE
  60. SGR1806-20: A Second, Intense Burst Localized by HETE
  61. SGR1806-20: Localization by HETE
  62. IPN triangulation of GRB010613
  63. HETE Fully-Automated GCN Notices
  64. GRB000301C: Late-time HST/STIS observation
  65. GRB010518: a faint BeppoSAX detection
  66. GRB000418: HST/STIS Second-epoch Observations
  67. X-ray precursors to the large flare from SGR 1900+14
  68. SGR 1900+14 : RXTE observations
  69. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  70. Millimeter observation of SGR 1900+14
  71. SGR 1900+14, Chandra observations
  72. Chandra Observations of SGR 1900+14
  73. SGR1900+14, I-band observations
  74. IPN Triangulation of the Giant Flare from SGR1900+14
  75. GRB010412, field photometry
  76. Giant flare from SGR1900+14
  77. GRB 010326b Optical Observations
  78. GRB010412: BeppoSAX GRBM and WFC observations
  79. GRB010324, revised field photometry
  80. GRB 980326: Late-time HST/STIS observations
  81. GRB010324, field photometry
  82. GRB010326B, field photometry
  83. GRB010326, field photometry
  84. GRB010220, field photometry
  85. Further Optical Observations of GRB 010324
  86. GRB010222, CXO X-ray observations
  87. GRB010324, optical observations
  88. GRB010326B: Localization by HETE (2nd GRB for this date)
  89. GRB 010326 optical observations
  90. GRB010326: Refined Localization by HETE
  91. GRB010326: Localization by HETE
  92. Optical Observations of GRB 010324
  93. GRB010222, late-time optical observation
  94. Support extension to the BeppoSAX mission
  95. GRB 010222 - HEGRA GeV/TeV Observations
  96. GRB010222 - Optical observation
  97. GRB 010222, Optical Observations
  98. GRB 010214, I-band data
  99. GRB010222 further R-band photometry
  100. GRB 010222: Keck Spectroscopy

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