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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"

26040 results found.

  1. GRB 050126: Radio Observations
  2. GRB050128 Swift-BAT observations
  3. GRB 050128: Swift XRT prompt afterglow position
  4. GRB 050124: K-band afterglow observations
  5. GRB050126: MASTER optical limit for KECK OT
  6. GRB050126: Burst Parameters Measured by BAT
  7. GRB050126: MASTER optical observations
  8. GRB 050126: Detection of NIR afterglow with Keck/NIRC
  9. GRB 050126: Prompt XRT detection and localization
  10. GRB 050124: NIR afterglow confirmed with Keck/NIRC
  11. GRB050124: No Swift UVOT Detection of Afterglow Emission
  12. GRB 050117a: Radio Observations
  13. GRB 050124: NIR Candidates from Keck/NIRC
  14. GRB050124,optical observation
  15. GRB050124: Updated Swift XRT Position and Fluxes
  16. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  17. GRB050124: Refined BAT position, spectral and fluence information
  18. GRB050124: Swift-BAT position of a double-peaked burst
  19. Unusual optical transient (GRB ???)
  20. GRB050117a: Radio Observations
  21. GRB050117a: Refined analysis
  22. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  23. GRB050117: Palomar WIRC Ks-band observations
  24. GRB050117b: Swift-BAT detection of a weak burst
  25. GRB050117: optical observation
  26. GRB 050117, I-band observations
  27. GRB 050117: Optical observation
  28. GRB050117: Refined XRT position
  29. GRB050117: MASTER optical observations
  30. MASTER:GRB050117 SWIFT
  31. GRB050117: Swift-BAT detection of a long multi-peaked burst
  32. GRB050117: Swift XRT Position
  33. SGR1806-20: Swift-BAT observations of two additional bursts
  34. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  35. SGR 1806-20: Temporal and Spectral behavior of radio transient
  36. SGR 1806-20, RHESSI observations of the 041227 giant flare
  37. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  38. GRB 041217: Optical observations
  39. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  40. GRB041219, early time observations
  41. GRB041228: ROTSE-III Optical Observations
  42. GRB041228: Swift-BAT detection of a burst
  43. GRB041219; RXTE ASM Observations
  44. NIR Observations of GRB 041219
  45. GRB041226: ROTSE-III Optical Observations
  46. GRB041226: Swift-BAT detection of a burst
  47. GRB041223: decay of the afterglow
  48. GRB041224: ROTSE-III Optical Observations
  49. GRB 041223: XRT afterglow spectrum and light curve
  50. GRB 041223 Fluence measured by Swift-BAT
  51. GRB041224: Swift-BAT detection of a soft burst
  52. GRB041223: optical and NIR observations with REM
  53. Swift-BAT Time History of GRB041219
  54. GRB 041223: J-band observations of the afterglow
  55. GRB 041223: Detection of Optical Transient with LCO40
  56. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  57. GRB041223: ROTSE-III Optical Observations
  58. GRB041223: Swift-BAT detection of a bright long burst
  59. GRB 041218: optical observations
  60. GRB 041219: WSRT Radio Afterglow Detection
  61. GRB 041219 : optical follow-up observations
  62. GRB041220: Swift-BAT burst
  63. GRB 041219 Optical Observations
  64. GRB041219c: Third Burst in One Day from Swift-BAT
  65. GRB041219: Optical Afterglow Detection
  66. GRB041219: Continued NIR Observations
  67. GRB041219b: A Swift-BAT burst
  68. GRB 041219: Radio Afterglow Detection
  69. GRB 041218 : Radio Observations
  70. GRB 041218: R-band optical observations
  71. GRB041218: Liverpool Telescope optical observations
  72. GRB041218: optical observations
  73. GRB041219: Confirmed NIR Afterglow
  74. GRB041218: Continued P60 Optical Observations
  75. Swift-BAT detection of the bright long burst GRB041219
  76. GRB 041219: Infrared Afterglow Candidate
  77. GRB 041219: Infrared Afterglow Candidate
  78. GRB041218, BVRcIc field calibration
  79. GRB041218: optical observations
  80. GRB041217: optical limit 30 min after GRB
  81. GRB 041218: Optical observations
  82. GRB041217: Optical Observations
  83. GRB041217: NIR and optical observations with REM
  84. GRB041217: P60 Optical Observations
  85. GRB041217: Infrared Observations
  86. GRB041217: The First GRB Located On-Board Swift
  87. Optical transient (GRB?) in Lynx
  88. GRB041211, BVRcIc field calibration
  89. GRB041211: P60 optical imaging
  90. GRB970815: Discovery of Optical Afterglow
  91. GRB 040924: Afterglow Color
  92. GRB 041006: GETS Optical Afterglow Observation
  93. GRB 041006: Optical Observations
  94. GRB041006, late-time optical photometry
  95. GRB041006: RTT150 Optical Observations
  96. HST Observations: XRF 040701 and 040812
  97. GRB041006: RTT150 Optical Observations
  98. GRB 041016: Optical limits
  99. GRB041006: Near Infrared observations
  100. GRB040924, BVRcIc field calibration

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