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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.

Advanced Search Examples (click to copy):

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

19129 results found.

  1. GRB050315: Swift-BAT Refined analysis
  2. Non-detection of GRB050315 in ATCA Radio Observations
  3. GRB 050315: Swift XRT Position
  4. GRB 050315: Early Observations with Swift/UVOT
  5. Swift-BAT detection of GRB 050315
  6. GRB050223: No XMM-Newton OM detection of afterglow emission
  7. GRB050309: CONCAM pre-trigger and trigger coincident optical
  8. GRB 050126: Redshift determination
  9. Swift-BAT trigger 107873: No Swift XRT counterpart
  10. GRB 050306: Confirmation of X-ray afterglow
  11. GRB 050309, Early optical limits from RAPTOR
  12. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  13. GRB 050309 : Lulin R-band observation
  14. Swift 107873: P60 Optical Observations
  15. GRB 050306: CORRECTION to date of observation
  16. GRB 050306: No Swift UVOT Optical Counterpart Detected
  17. GRB 050306: Possible X-ray Afterglow Position from the Swift
  18. Swift trigger 107518: optical observation
  19. GRB 050306,optical observation
  20. GRB 050306: Swift-BAT detection of a long burst
  21. GRB050215B: Late-Time Swift UVOT Observations
  22. PROMPT VRcIc Observations of GRB 050223
  23. GRB 050223: optical observations
  24. GRB050223 XMM-Newton observation
  25. INTEGRAL detection of GRB 050223
  26. GRB050223: No Swift UVOT Detection of Afterglow Emission
  27. GRB050223: ROTSE-III Optical Observations
  28. GRB 050223 Swift/BAT detection of a burst
  29. GRB 050223: Swift XRT Position
  30. GRB050219b: CORRECTION to time of UVOT observations
  31. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  32. GRB 050219b: CORRECTION to refined XRT position
  33. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  34. GRB 050219b: Refined XRT position
  35. GRB 050219b: Swift-BAT detection of a burst
  36. GRB 050219b: CORRECTION: Swift XRT Position
  37. GRB 050219b: Swift XRT Position
  38. GRB 050219a, optical observations
  39. GRB 050219a: Refined XRT position
  40. GRB050219a: No Swift UVOT Detection of Afterglow Emission
  41. GRB 050219: Swift-BAT detection of a burst
  42. GRB050215b: Swift UVOT Detection of Afterglow Emission
  43. GRB 050219: Prompt X-ray position
  44. GRB 050215b: XRT confirmation of IR afterglow candidate
  45. GRB050215b: P60 Optical Observations
  46. GRB 050215b: Swift XRT Source Variability
  47. GRB 050215B: candidate afterglow
  48. GRB 050215b : Lulin follow-up observation
  49. GRB 050215b, BOOTES-2 simultaneous optical observations
  50. GRB 050215B: UKIRT K-band imaging
  51. GRB 050215b: Swift XRT Observations
  52. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  53. GRB050215a: No Swift UVOT Detection of Afterglow Emission
  54. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  55. GRB050215B: ROTSE-III optical observations
  56. GRB050215A: ROTSE-III Optical Observations
  57. short/hard GRB 050202, optical observations
  58. GRB 050128: Radio observations
  59. Further analysis of the short Swift-BAT GRB 050202
  60. GRB 050202: Second epoch radio observations
  61. GRB050202: Radio Observations
  62. GRB 050202: Short burst detected by Swift-BAT
  63. SGR1806-20: Swift-BAT detection of a large normal burst
  64. GRB050128: Faulkes Telescope South observations
  65. GRB050128,optical observations
  66. GRB050126: Updated Swift XRT Position
  67. GRB 050126: Radio Observations
  68. GRB050128 Swift-BAT observations
  69. GRB 050128: Swift XRT prompt afterglow position
  70. GRB 050124: K-band afterglow observations
  71. GRB050126: MASTER optical limit for KECK OT
  72. GRB050126: Burst Parameters Measured by BAT
  73. GRB050126: MASTER optical observations
  74. GRB 050126: Prompt XRT detection and localization
  75. GRB050124: No Swift UVOT Detection of Afterglow Emission
  76. GRB 050117a: Radio Observations
  77. GRB050124,optical observation
  78. GRB050124: Updated Swift XRT Position and Fluxes
  79. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  80. GRB050124: Refined BAT position, spectral and fluence information
  81. GRB050124: Swift-BAT position of a double-peaked burst
  82. GRB050117a: Radio Observations
  83. GRB050117a: Refined analysis
  84. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  85. GRB050117b: Swift-BAT detection of a weak burst
  86. GRB050117: optical observation
  87. GRB 050117, I-band observations
  88. GRB 050117: Optical observation
  89. GRB050117: Refined XRT position
  90. GRB050117: MASTER optical observations
  91. MASTER:GRB050117 SWIFT
  92. GRB050117: Swift-BAT detection of a long multi-peaked burst
  93. GRB050117: Swift XRT Position
  94. SGR1806-20: Swift-BAT observations of two additional bursts
  95. SGR 1806-20, RHESSI observations of the 041227 giant flare
  96. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  97. GRB 041217: Optical observations
  98. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  99. GRB041228: ROTSE-III Optical Observations
  100. GRB041228: Swift-BAT detection of a burst

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