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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"

27391 results found.

  1. GRB050209: TAROT optical observations
  2. GRB 050209(=U11568): Duration and spectrum
  3. GRB050209: REM optical observations
  4. GRB 050209 I-band observation
  5. GRB 050209 Optical observations
  6. GRB050209: P60 Optical Observations
  7. GRB 050128: Radio observations
  8. Further analysis of the short Swift-BAT GRB 050202
  9. GRB 050202: Short burst detected by Swift-BAT
  10. GRB 050128 Optical observation with REM
  11. SGR1806-20: Swift-BAT detection of a large normal burst
  12. GRB 050128: near-infrared observations with REM
  13. GRB050128,optical observations
  14. GRB050128 Swift-BAT observations
  15. GRB 050128: Swift XRT prompt afterglow position
  16. GRB050126: MASTER optical limit for KECK OT
  17. GRB050126: Burst Parameters Measured by BAT
  18. GRB050126: MASTER optical observations
  19. GRB 050124 I-band observation
  20. GRB050124,optical observation
  21. GRB 050124 : Lulin R-band follow-up observation
  22. GRB050124: Updated Swift XRT Position and Fluxes
  23. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  24. GRB050124: Refined BAT position, spectral and fluence information
  25. GRB 050123 : I-band follow-up observation
  26. GRB050123,optical observation
  27. GRB 050123: KAIT observations
  28. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  29. GRB050117: Refined XRT position
  30. GRB050117: MASTER optical observations
  31. MASTER:GRB050117 SWIFT
  32. GRB050117: Swift XRT Position
  33. Triangulation of Short Hard GRB050112 (large error box)
  34. SGR 1806-20: Further VLA Observations
  35. SGR1806-20: Swift-BAT observations of two additional bursts
  36. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  37. Further VLA observations of SGR 1806-20
  38. SGR 1806-20 and extragalactic short-duration GRBs
  39. Further ATCA observations of SGR 1806-20
  40. Fourth Epoch VLA observations of SGR 1806-20
  41. SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
  42. ATCA observations of SGR 1806-20
  43. SGR 1806-20, RHESSI observations of the 041227 giant flare
  44. Third epoch observations of SGR 1806-20 with VLA
  45. Second Epoch VLA observations of SGR 1806-20
  46. Second-epoch VLA observations of SGR 1806-20
  47. SGR1806 VLA Observations
  48. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  49. GRB 041217: Optical observations
  50. GRB041228: Swift-BAT detection of a burst
  51. GRB041219; RXTE ASM Observations
  52. NIR Observations of GRB 041219
  53. GRB041226: Swift-BAT detection of a burst
  54. GRB041223: decay of the afterglow
  55. GRB 041224: near-infrared observations with REM
  56. GRB 041223 Fluence measured by Swift-BAT
  57. GRB041223: optical and NIR observations with REM
  58. Swift-BAT Time History of GRB041219
  59. GRB 041219: TAROT optical observations
  60. GRB 041218: TAROT optical observations
  61. GRB 041223: J-band observations of the afterglow
  62. GRB 041219c: PROMPT Observations
  63. GRB041223: Swift-BAT detection of a bright long burst
  64. GRB 041218: optical observations
  65. GRB 041219 : optical follow-up observations
  66. Deep RAPTOR observations during GRB 041219
  67. GRB 041218 Optical Observations
  68. GRB041219: Continued NIR Observations
  69. GRB 041219 ,optical observation
  70. GRB 041219: Radio Afterglow Detection
  71. GRB 041218 : Radio Observations
  72. GRB 041218: R-band optical observations
  73. GRB041218: optical observations
  74. GRB041219: Confirmed NIR Afterglow
  75. Swift-BAT detection of the bright long burst GRB041219
  76. GRB 041219: Infrared Afterglow Candidate
  77. GRB041219, BVRcIc field calibration
  78. GRB 041219: Infrared Afterglow Candidate
  79. GRB041218, BVRcIc field calibration
  80. GRB041219: Prompt Optical Observations from ROTSE-IIIb
  81. GRB 041219 - A long GRB detected by INTEGRAL
  82. GRB 041219: PAIRITEL IR Observations, < 3 minutes after trigger
  83. GRB 041217: PROMPT Observations
  84. GRB 041217: LCO40 Optical Observations and Possible Candidates
  85. GRB 041218 - A long GRB detected by integral
  86. GRB041217: NIR and optical observations with REM
  87. GRB041217: Infrared Observations
  88. GRB041217: The First GRB Located On-Board Swift
  89. GRB041211: Faulkes Telescope continued optical monitoring
  90. Optical Transient in Lynx not a GRB
  91. Optical transient (GRB?) in Lynx
  92. GRB041211: RAPTOR observations
  93. GRB041211: Ashra Prototype optical observation
  94. GRB041211, BVRcIc field calibration
  95. GRB041211,optical observation
  96. GRB 041211: Infrared Observations
  97. GRB 041211: KAIT observations
  98. GRB 041211: Optical follow-up in East Asian region
  99. Triangulation of short GRB 041116 (large error box)
  100. GRB 040924: Afterglow Color

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