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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"

42259 results found.

  1. GRB 050126: Detection of NIR afterglow with Keck/NIRC
  2. GRB 050126: Prompt XRT detection and localization
  3. GRB 050124: NIR afterglow confirmed with Keck/NIRC
  4. GRB050124: No Swift UVOT Detection of Afterglow Emission
  5. GRB 050124, SMARTS optical/IR observations
  6. GRB 050117a: Radio Observations
  7. GRB 050124 I-band observation
  8. GRB 050124: NIR Candidates from Keck/NIRC
  9. GRB050124,optical observation
  10. GRB050124: Updated Swift XRT Position and Fluxes
  11. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  12. GRB050124: Refined BAT position, spectral and fluence information
  13. GRB050124: Swift-BAT position of a double-peaked burst
  14. GRB 050123 : I-band follow-up observation
  15. GRB050123: optical limit 1.8h before GRB
  16. GRB050123,optical observation
  17. GRB 050123: KAIT observations
  18. GRB050123: P60 Observations
  19. GRB 050123(=H3666): A GRB Localized in Real Time by HETE
  20. CFHTLS optical transient unlikely to be a GRB
  21. Unusual optical transient (GRB ???)
  22. GRB050117a: Refined analysis
  23. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  24. GRB050117: Palomar WIRC Ks-band observations
  25. GRB050117b: Swift-BAT detection of a weak burst
  26. GRB050117: optical observation
  27. GRB 050117, I-band observations
  28. GRB 050117: Optical observation
  29. GRB050117: MASTER optical observations
  30. GRB050117: Swift-BAT detection of a long multi-peaked burst
  31. GRB050117: Swift XRT Position
  32. Triangulation of Short Hard GRB050112 (large error box)
  33. SGR 1806-20: Further VLA Observations
  34. SGR 1806-20: Further low frequency GMRT results
  35. SGR 1806-20: Further VLA Observations
  36. SGR1806-20: Swift-BAT observations of two additional bursts
  37. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  38. Further VLA observations of SGR 1806-20
  39. SGR 1806-20 and extragalactic short-duration GRBs
  40. Further ATCA observations of SGR 1806-20
  41. Fourth Epoch VLA observations of SGR 1806-20
  42. SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
  43. SGR 1806-20: Temporal and Spectral behavior of radio transient
  44. ATCA observations of SGR 1806-20
  45. SGR 1806-20, RHESSI observations of the 041227 giant flare
  46. Third epoch observations of SGR 1806-20 with VLA
  47. Second Epoch VLA observations of SGR 1806-20
  48. Second-epoch VLA observations of SGR 1806-20
  49. SGR1806: Detection of a Sudden Ionospheric Disturbance
  50. VLA observations of SGR 1806-20
  51. SGR1806 VLA Observations
  52. VLA observations of SGR 1806-20
  53. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  54. GRB 041217: Optical observations
  55. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  56. GRB041219, early time observations
  57. Detection of the SGR 1806-20 giant outburst back-scattered by the
  58. The giant outburst from SGR 1806-20
  59. IPN localization of giant flare from SGR1806-20
  60. Giant flare from SGR 1806-20 detected by INTEGRAL
  61. GRB041228: ROTSE-III Optical Observations
  62. GRB041228: Swift-BAT detection of a burst
  63. GRB041219; RXTE ASM Observations
  64. NIR Observations of GRB 041219
  65. GRB041226: ROTSE-III Optical Observations
  66. GRB041226: Swift-BAT detection of a burst
  67. GRB041223: decay of the afterglow
  68. GRB041224: ROTSE-III Optical Observations
  69. GRB 041224: near-infrared observations with REM
  70. GRB 041223: XRT afterglow spectrum and light curve
  71. GRB 041223 Fluence measured by Swift-BAT
  72. GRB041224: Swift-BAT detection of a soft burst
  73. GRB041223: optical and NIR observations with REM
  74. Swift-BAT Time History of GRB041219
  75. GRB 041219: TAROT optical observations
  76. GRB 041218: TAROT optical observations
  77. GRB 041223: J-band observations of the afterglow
  78. GRB 041223: Detection of Optical Transient with LCO40
  79. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  80. GRB 041219c: PROMPT Observations
  81. GRB041223: ROTSE-III Optical Observations
  82. GRB041223: Swift-BAT detection of a bright long burst
  83. GRB 041218: optical observations
  84. Very high activity of SGR 1806-20
  85. GRB 041219: Second Epoch WSRT Radio Observations
  86. GRB 041219: WSRT Radio Afterglow Detection
  87. GRB 041219: Keck IR Observations and Astrometric Refinement of the
  88. GRB 041218: Optical observations
  89. GRB 041219 : optical follow-up observations
  90. GRB041220: Swift-BAT burst
  91. Deep RAPTOR observations during GRB 041219
  92. GRB 041218 Optical Observations
  93. GRB 041219 Optical Observations
  94. GRB041219c: Third Burst in One Day from Swift-BAT
  95. GRB041219: Optical Afterglow Detection
  96. GRB041219: Continued NIR Observations
  97. GRB041219b: A Swift-BAT burst
  98. GRB 041219 ,optical observation
  99. GRB 041219: Radio Afterglow Detection
  100. GRB 041218 : Radio Observations

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