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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"

11503 results found.

  1. Renewal of SGR 1806-20 activity
  2. GRB050502A: Optical Observations
  3. GRB 050502: INTEGRAL results
  4. GRB 050502 - A long GRB detected with INTEGRAL
  5. GRB 050421: SLOTIS observations
  6. GRB 050421: IR Observations
  7. GRB 050421: ROTSE-III Optical Limits
  8. GRB 050421: NIR observations
  9. Swift Detection of GRB050421
  10. GRB050326: analysis of the XMM-Newton observation
  11. GRB 050412: Chandra observations
  12. Swift-BAT detection of the bright and long GRB 050418
  13. GRB 050416B: optical observations
  14. GRB 050416: Swift-BAT refined analysis
  15. GRB 050416: Radio observations
  16. GRB 050408: RTT150 optical observations
  17. GRB050408: optical observation
  18. GRB 050412 : XingLong optical observation
  19. GRB050412: optical limit before and during GRB
  20. GRB050412: ROTSE-III Optical Limits
  21. GRB 050410, optical observations
  22. GRB 050410, optical observations
  23. GRB 050408: Swift XRT measurement of possible jet break
  24. Swift-BAT detection of GRB 050410
  25. GRB 050410: Swift XRT Position
  26. GRB 050408: Optical limit at 20 min after the burst
  27. GRB 050408, optical observations
  28. GRB 050408,optical observation
  29. GRB 050408: Mercator Optical Observations
  30. GRB 050408, optical observations
  31. GRB 050408: ROTSE-III Optical Limits
  32. Konus-Wind observation of GRB 050401
  33. GRB 050401 BAT refined analysis
  34. Swift Trigger 113225: P60 Observations
  35. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  36. Swift-BAT detection of GRB 050401
  37. GRB 050401: Prompt XRT position
  38. GRB050331: No Afterglow Detected
  39. Swift-BAT detection of GRB 050331
  40. Konus-Wind observation of GRB 050326
  41. GRB050326: optical limit 33min before GRB
  42. GRB050319, optical observations
  43. GRB050319: optical observation, March 20-22
  44. Swift-BAT detection of a bright outburst from SGR1806-20
  45. GRB 050319: Absorption redshift from the Nordic Optical Telescope
  46. GRB 050319: ROTSE-III Refined Analysis
  47. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  48. GRB 050319: NIR afterglow candidate
  49. GRB 050319:Near IR afterglow
  50. GRB050319: BR optical photometry
  51. GRB 050319: Optical observation
  52. GRB050223: analysis of the XMM-Newton observation
  53. GRB050315: Radio afterglow
  54. GRB 050315: Absorption redshift
  55. GRB 050315: Optical afterglow identification
  56. GRB 050315: Swift XRT Position
  57. Swift-BAT detection of GRB 050315
  58. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  59. GRB 050306: R-band observations
  60. Swift trigger 107518: optical observation
  61. Ongoing activity of SGR 1806-20 after the giant flare
  62. GRB050215B: Late-Time Swift UVOT Observations
  63. INTEGRAL detection of GRB 050223
  64. GRB 050223 : Planned XMM-Newton observation
  65. GRB050223: ROTSE-III Optical Observations
  66. GRB 050219a: Optical observations from LCO
  67. GRB 050215b: Swift XRT Source Variability
  68. GRB 050215b : Lulin follow-up observation
  69. GRB050215B: ROTSE-III optical observations
  70. GRB050215A: ROTSE-III Optical Observations
  71. short/hard GRB 050202, optical observations
  72. GRB 050129: a weak long GRB detected with INTEGRAL
  73. SGR1806-20: Swift-BAT detection of a large normal burst
  74. SGR 1806-20: GMRT results at 240 MHz band.
  75. SGR 1806-20: low frequency GMRT results of 2005 Jan 16.
  76. GRB 050128: Swift XRT prompt afterglow position
  77. GRB050126: Burst Parameters Measured by BAT
  78. GRB 050124 : Lulin R-band follow-up observation
  79. GRB050124: Refined BAT position, spectral and fluence information
  80. Unusual optical transient (GRB ???)
  81. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  82. GRB050117b: Swift-BAT detection of a weak burst
  83. GRB050117: optical observation
  84. GRB050117: Refined XRT position
  85. GRB050117: MASTER optical observations
  86. MASTER:GRB050117 SWIFT
  87. SGR 1806-20: RXTE/PCA pulse frequency during flare
  88. Triangulation of Short Hard GRB050112 (large error box)
  89. SGR 1806-20: Further VLA Observations
  90. SGR 1806-20: Further low frequency GMRT results
  91. SGR 1806-20: Further VLA Observations
  92. SGR1806-20: Swift-BAT observations of two additional bursts
  93. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  94. Further VLA observations of SGR 1806-20
  95. SGR 1806-20 and extragalactic short-duration GRBs
  96. Further ATCA observations of SGR 1806-20
  97. Fourth Epoch VLA observations of SGR 1806-20
  98. SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
  99. SGR 1806-20: Temporal and Spectral behavior of radio transient
  100. ATCA observations of SGR 1806-20

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