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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"

24596 results found.

  1. GRB 000131: HST Detection of the Host Galaxy
  2. GRB 970828: HST Observations of the Host Galaxy
  3. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  4. GRB011019: Subaru Optical Observations
  5. GRB 011030 I-band Observations
  6. GRB 011030 K-band Observations
  7. GRB010921, optical observations
  8. GRB011030 - further refinement WFC position
  9. GRB 011030, Radio observations
  10. GRB011030: radio search
  11. GRB 010921: Possible supernova component
  12. GRB010921, optical observation at early time
  13. GRB 010921, I-band observations
  14. GRB011019, optical observations
  15. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  16. GRB 010921: The afterglow of HETE #1761
  17. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  18. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  19. GRB010923 as seen by BeppoSAX GRBM
  20. GRB010928(=H1770): Localization of a Long GRB by HETE
  21. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  22. GRB010921, negative optical observations
  23. GRB010921 field photometry
  24. H1761: A Bright GRB Detected by HETE
  25. GRB000926, Host Galaxy Observations
  26. GRB001109, Host Galaxy Spectroscopic Observations
  27. Probable SGR or Short Duration GRB Detected by HETE
  28. GCN and HETE status
  29. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  30. GRB 010222 - WHT BVRI images
  31. SGR1900+14 burst seen by HETE: BeppoSAX data
  32. GRB 010629 Optical Observations
  33. SGR1900+14: High Fluence Burst Localized by HETE
  34. GRB010629, optical observations
  35. GRB010629: A Burst Localized by HETE
  36. SGR1900+14: Second Burst Localized by HETE
  37. SGR1900+14: A Burst Localized by HETE
  38. SGR1806-20: A Second, Intense Burst Localized by HETE
  39. SGR1806-20: Localization by HETE
  40. HETE Fully-Automated GCN Notices
  41. GRB000301C: Late-time HST/STIS observation
  42. GRB010518: a faint BeppoSAX detection
  43. GRB000418: HST/STIS Second-epoch Observations
  44. X-ray precursors to the large flare from SGR 1900+14
  45. GRB010427, Gamma Ray Observations
  46. SGR 1900+14: No evidence of extended X-ray emission
  47. SGR 1900+14 : RXTE observations
  48. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  49. SGR 1900+14: Correction to GCN 1049
  50. GRB 010222 /corrections to VBT data
  51. Millimeter observation of SGR 1900+14
  52. SGR 1900+14: Detection of extended X-ray emission
  53. SGR 1900+14, Chandra observations
  54. SGR1900+14, I-band observations
  55. GRB010412, field photometry
  56. Giant flare from SGR1900+14
  57. GRB 010326b Optical Observations
  58. GRB010412: BeppoSAX GRBM and WFC observations
  59. GRB010324, revised field photometry
  60. REVISED LOCATION OF GRB010326A
  61. GRB 980326: Late-time HST/STIS observations
  62. GRB010324, field photometry
  63. GRB010326B, field photometry
  64. GRB010326, field photometry
  65. GRB010220, field photometry
  66. Further Optical Observations of GRB 010324
  67. GRB010222, CXO X-ray observations
  68. GRB010324, optical observations
  69. GRB010326B: Localization by HETE (2nd GRB for this date)
  70. GRB 010326 optical observations
  71. GRB010326: Refined Localization by HETE
  72. GRB010326: Localization by HETE
  73. Optical Observations of GRB 010324
  74. GRB010222, late-time optical observation
  75. Support extension to the BeppoSAX mission
  76. GRB 010222 - HEGRA GeV/TeV Observations
  77. GRB010222: Chandra X-ray Observatory Observation
  78. GRB010222: Sub-millimeter vanishing act
  79. GRB010222 - Optical observation
  80. GRB 010222, Optical Observations
  81. GRB010222 - Optical observation
  82. GRB 010222: High-Resolution Keck Spectroscopy
  83. GRB 010214, I-band data
  84. GRB 010222
  85. GRB010222 further R-band photometry
  86. GRB010222: R-band data
  87. GRB 010222: Keck Spectroscopy
  88. GRB010214, field photometry
  89. GRB010222, field photometry
  90. GRB010222 further R-band photometry
  91. GRB010222, possible increase of optical decay slope
  92. GRB 010222 Kyoto optical observation
  93. GRB010222 R-BAND OBSERVATION
  94. GRB010214 follow-up from Hanle
  95. GRB 010222: Near-IR Observations
  96. GRB 010222: Optical Observations
  97. GRB010222: Optical decay slope
  98. GRB 010214, Optical Observations
  99. GRB010222, radio observations
  100. GRB010222, optical observations

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