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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').

17099 results found.

  1. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  2. GRB 050219b: CORRECTION to refined XRT position
  3. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  4. GRB 050219b: Refined XRT position
  5. GRB 050219b: Swift-BAT detection of a burst
  6. GRB 050219b: CORRECTION: Swift XRT Position
  7. GRB 050219b: Swift XRT Position
  8. GRB 050219a, optical observations
  9. GRB 050219a: Refined XRT position
  10. GRB050219a: No Swift UVOT Detection of Afterglow Emission
  11. GRB 050219: Swift-BAT detection of a burst
  12. GRB050215b: Swift UVOT Detection of Afterglow Emission
  13. GRB 050219: Prompt X-ray position
  14. GRB 050215b: XRT confirmation of IR afterglow candidate
  15. GRB050215b: P60 Optical Observations
  16. GRB 050215b: Swift XRT Source Variability
  17. GRB 050215B: candidate afterglow
  18. GRB 050215b : Lulin follow-up observation
  19. GRB 050215b, BOOTES-2 simultaneous optical observations
  20. GRB 050215B: UKIRT K-band imaging
  21. GRB 050215b: Swift XRT Observations
  22. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  23. GRB050215a: No Swift UVOT Detection of Afterglow Emission
  24. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  25. GRB050215B: ROTSE-III optical observations
  26. GRB050215A: ROTSE-III Optical Observations
  27. short/hard GRB 050202, optical observations
  28. GRB 050128: Radio observations
  29. Further analysis of the short Swift-BAT GRB 050202
  30. GRB 050202: Second epoch radio observations
  31. GRB050202: Radio Observations
  32. GRB 050202: Short burst detected by Swift-BAT
  33. SGR1806-20: Swift-BAT detection of a large normal burst
  34. GRB050128: Faulkes Telescope South observations
  35. GRB050128,optical observations
  36. GRB050126: Updated Swift XRT Position
  37. GRB 050126: Radio Observations
  38. GRB050128 Swift-BAT observations
  39. GRB 050128: Swift XRT prompt afterglow position
  40. GRB 050124: K-band afterglow observations
  41. GRB050126: MASTER optical limit for KECK OT
  42. GRB050126: Burst Parameters Measured by BAT
  43. GRB050126: MASTER optical observations
  44. GRB 050126: Prompt XRT detection and localization
  45. GRB050124: No Swift UVOT Detection of Afterglow Emission
  46. GRB 050117a: Radio Observations
  47. GRB050124,optical observation
  48. GRB050124: Updated Swift XRT Position and Fluxes
  49. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  50. GRB050124: Refined BAT position, spectral and fluence information
  51. GRB050124: Swift-BAT position of a double-peaked burst
  52. GRB050117a: Radio Observations
  53. GRB050117a: Refined analysis
  54. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  55. GRB050117b: Swift-BAT detection of a weak burst
  56. GRB050117: optical observation
  57. GRB 050117, I-band observations
  58. GRB 050117: Optical observation
  59. GRB050117: Refined XRT position
  60. GRB050117: MASTER optical observations
  61. MASTER:GRB050117 SWIFT
  62. GRB050117: Swift-BAT detection of a long multi-peaked burst
  63. GRB050117: Swift XRT Position
  64. SGR1806-20: Swift-BAT observations of two additional bursts
  65. SGR 1806-20, RHESSI observations of the 041227 giant flare
  66. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  67. GRB 041217: Optical observations
  68. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  69. GRB041228: ROTSE-III Optical Observations
  70. GRB041228: Swift-BAT detection of a burst
  71. GRB041219; RXTE ASM Observations
  72. NIR Observations of GRB 041219
  73. GRB041226: ROTSE-III Optical Observations
  74. GRB041226: Swift-BAT detection of a burst
  75. GRB041223: decay of the afterglow
  76. GRB041224: ROTSE-III Optical Observations
  77. GRB 041223: XRT afterglow spectrum and light curve
  78. GRB 041223 Fluence measured by Swift-BAT
  79. GRB041224: Swift-BAT detection of a soft burst
  80. GRB041223: optical and NIR observations with REM
  81. Swift-BAT Time History of GRB041219
  82. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  83. GRB041223: ROTSE-III Optical Observations
  84. GRB041223: Swift-BAT detection of a bright long burst
  85. GRB041220: Swift-BAT burst
  86. GRB 041219 Optical Observations
  87. GRB041219c: Third Burst in One Day from Swift-BAT
  88. GRB041219b: A Swift-BAT burst
  89. Swift-BAT detection of the bright long burst GRB041219
  90. GRB041217: optical limit 30 min after GRB
  91. GRB041217: Optical Observations
  92. GRB041217: NIR and optical observations with REM
  93. GRB041217: P60 Optical Observations
  94. GRB041217: Infrared Observations
  95. GRB041217: The First GRB Located On-Board Swift
  96. GRB040916: Optical observations
  97. GRB040422: optical and NIR observations at the VLT
  98. GRB040223, improved XMM position
  99. SN 2003jd (SN/GRB?) - possible association with GRB 030929

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