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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

37912 results found.

  1. GRB 050202: Short burst detected by Swift-BAT
  2. GRB 050128 Optical observation with REM
  3. GRB 050129: a weak long GRB detected with INTEGRAL
  4. SGR1806-20: Swift-BAT detection of a large normal burst
  5. GRB050128: Faulkes Telescope South observations
  6. GRB 050124: Radio Observations
  7. GRB 050128: near-infrared observations with REM
  8. GRB050128,optical observations
  9. GRB 050126: A NIR afterglow candidate in the revised XRT error circle
  10. GRB050126: Updated Swift XRT Position
  11. GRB 050126: Radio Observations
  12. GRB050128 Swift-BAT observations
  13. GRB 050128: Swift XRT prompt afterglow position
  14. GRB 050124: K-band afterglow observations
  15. GRB050126: MASTER optical limit for KECK OT
  16. GRB050126: Burst Parameters Measured by BAT
  17. GRB050126: MASTER optical observations
  18. GRB 050126: Detection of NIR afterglow with Keck/NIRC
  19. GRB 050126: Prompt XRT detection and localization
  20. GRB 050124: NIR afterglow confirmed with Keck/NIRC
  21. GRB050124: No Swift UVOT Detection of Afterglow Emission
  22. GRB 050124, SMARTS optical/IR observations
  23. GRB 050117a: Radio Observations
  24. GRB 050124 I-band observation
  25. GRB 050124: NIR Candidates from Keck/NIRC
  26. GRB050124,optical observation
  27. GRB 050124 : Lulin R-band follow-up observation
  28. GRB050124: Updated Swift XRT Position and Fluxes
  29. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  30. GRB050124: Refined BAT position, spectral and fluence information
  31. GRB050124: Swift-BAT position of a double-peaked burst
  32. GRB 050123 : I-band follow-up observation
  33. GRB050123: optical limit 1.8h before GRB
  34. GRB050123,optical observation
  35. GRB 050123: KAIT observations
  36. GRB050123: P60 Observations
  37. GRB 050123(=H3666): A GRB Localized in Real Time by HETE
  38. CFHTLS optical transient unlikely to be a GRB
  39. Unusual optical transient (GRB ???)
  40. GRB050117a: Radio Observations
  41. GRB050117a: Refined analysis
  42. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  43. GRB050117b: Swift-BAT detection of a weak burst
  44. GRB050117: optical observation
  45. GRB 050117, I-band observations
  46. GRB 050117: Optical observation
  47. GRB050117: Refined XRT position
  48. GRB050117: MASTER optical observations
  49. MASTER:GRB050117 SWIFT
  50. GRB050117: Swift-BAT detection of a long multi-peaked burst
  51. GRB050117: Swift XRT Position
  52. Triangulation of Short Hard GRB050112 (large error box)
  53. SGR1806-20: Swift-BAT observations of two additional bursts
  54. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  55. SGR 1806-20 and extragalactic short-duration GRBs
  56. SGR 1806-20: Temporal and Spectral behavior of radio transient
  57. SGR 1806-20, RHESSI observations of the 041227 giant flare
  58. SGR1806: Detection of a Sudden Ionospheric Disturbance
  59. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  60. GRB 041217: Optical observations
  61. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  62. GRB041219, early time observations
  63. IPN localization of giant flare from SGR1806-20
  64. GRB041228: ROTSE-III Optical Observations
  65. GRB041228: Swift-BAT detection of a burst
  66. GRB041219; RXTE ASM Observations
  67. NIR Observations of GRB 041219
  68. GRB041226: ROTSE-III Optical Observations
  69. GRB041226: Swift-BAT detection of a burst
  70. GRB041223: decay of the afterglow
  71. GRB041224: ROTSE-III Optical Observations
  72. GRB 041224: near-infrared observations with REM
  73. GRB 041223: XRT afterglow spectrum and light curve
  74. GRB 041223 Fluence measured by Swift-BAT
  75. GRB041224: Swift-BAT detection of a soft burst
  76. GRB041223: optical and NIR observations with REM
  77. Swift-BAT Time History of GRB041219
  78. GRB 041219: TAROT optical observations
  79. GRB 041218: TAROT optical observations
  80. GRB 041223: J-band observations of the afterglow
  81. GRB 041223: Detection of Optical Transient with LCO40
  82. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  83. GRB 041219c: PROMPT Observations
  84. GRB041223: ROTSE-III Optical Observations
  85. GRB041223: Swift-BAT detection of a bright long burst
  86. GRB 041218: optical observations
  87. GRB 041219: Second Epoch WSRT Radio Observations
  88. GRB 041219: WSRT Radio Afterglow Detection
  89. GRB 041219: Keck IR Observations and Astrometric Refinement of the
  90. GRB 041218: Optical observations
  91. GRB 041219 : optical follow-up observations
  92. GRB041220: Swift-BAT burst
  93. Deep RAPTOR observations during GRB 041219
  94. GRB 041218 Optical Observations
  95. GRB 041219 Optical Observations
  96. GRB041219c: Third Burst in One Day from Swift-BAT
  97. GRB041219: Optical Afterglow Detection
  98. GRB041219: Continued NIR Observations
  99. GRB041219b: A Swift-BAT burst
  100. GRB 041219 ,optical observation

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