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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"

19128 results found.

  1. Non-detection of GRB050315 in ATCA Radio Observations
  2. GRB 050315: Swift XRT Position
  3. GRB 050315: Early Observations with Swift/UVOT
  4. Swift-BAT detection of GRB 050315
  5. GRB050223: No XMM-Newton OM detection of afterglow emission
  6. GRB050309: CONCAM pre-trigger and trigger coincident optical
  7. GRB 050126: Redshift determination
  8. Swift-BAT trigger 107873: No Swift XRT counterpart
  9. GRB 050306: Confirmation of X-ray afterglow
  10. GRB 050309, Early optical limits from RAPTOR
  11. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  12. GRB 050309 : Lulin R-band observation
  13. Swift 107873: P60 Optical Observations
  14. GRB 050306: CORRECTION to date of observation
  15. GRB 050306: No Swift UVOT Optical Counterpart Detected
  16. GRB 050306: Possible X-ray Afterglow Position from the Swift
  17. Swift trigger 107518: optical observation
  18. GRB 050306,optical observation
  19. GRB 050306: Swift-BAT detection of a long burst
  20. GRB050215B: Late-Time Swift UVOT Observations
  21. PROMPT VRcIc Observations of GRB 050223
  22. GRB 050223: optical observations
  23. GRB050223 XMM-Newton observation
  24. INTEGRAL detection of GRB 050223
  25. GRB050223: No Swift UVOT Detection of Afterglow Emission
  26. GRB050223: ROTSE-III Optical Observations
  27. GRB 050223 Swift/BAT detection of a burst
  28. GRB 050223: Swift XRT Position
  29. GRB050219b: CORRECTION to time of UVOT observations
  30. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  31. GRB 050219b: CORRECTION to refined XRT position
  32. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  33. GRB 050219b: Refined XRT position
  34. GRB 050219b: Swift-BAT detection of a burst
  35. GRB 050219b: CORRECTION: Swift XRT Position
  36. GRB 050219b: Swift XRT Position
  37. GRB 050219a, optical observations
  38. GRB 050219a: Refined XRT position
  39. GRB050219a: No Swift UVOT Detection of Afterglow Emission
  40. GRB 050219: Swift-BAT detection of a burst
  41. GRB050215b: Swift UVOT Detection of Afterglow Emission
  42. GRB 050219: Prompt X-ray position
  43. GRB 050215b: XRT confirmation of IR afterglow candidate
  44. GRB050215b: P60 Optical Observations
  45. GRB 050215b: Swift XRT Source Variability
  46. GRB 050215B: candidate afterglow
  47. GRB 050215b : Lulin follow-up observation
  48. GRB 050215b, BOOTES-2 simultaneous optical observations
  49. GRB 050215B: UKIRT K-band imaging
  50. GRB 050215b: Swift XRT Observations
  51. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  52. GRB050215a: No Swift UVOT Detection of Afterglow Emission
  53. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  54. GRB050215B: ROTSE-III optical observations
  55. GRB050215A: ROTSE-III Optical Observations
  56. short/hard GRB 050202, optical observations
  57. GRB 050128: Radio observations
  58. Further analysis of the short Swift-BAT GRB 050202
  59. GRB 050202: Second epoch radio observations
  60. GRB050202: Radio Observations
  61. GRB 050202: Short burst detected by Swift-BAT
  62. SGR1806-20: Swift-BAT detection of a large normal burst
  63. GRB050128: Faulkes Telescope South observations
  64. GRB050128,optical observations
  65. GRB050126: Updated Swift XRT Position
  66. GRB 050126: Radio Observations
  67. GRB050128 Swift-BAT observations
  68. GRB 050128: Swift XRT prompt afterglow position
  69. GRB 050124: K-band afterglow observations
  70. GRB050126: MASTER optical limit for KECK OT
  71. GRB050126: Burst Parameters Measured by BAT
  72. GRB050126: MASTER optical observations
  73. GRB 050126: Prompt XRT detection and localization
  74. GRB050124: No Swift UVOT Detection of Afterglow Emission
  75. GRB 050117a: Radio Observations
  76. GRB050124,optical observation
  77. GRB050124: Updated Swift XRT Position and Fluxes
  78. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  79. GRB050124: Refined BAT position, spectral and fluence information
  80. GRB050124: Swift-BAT position of a double-peaked burst
  81. GRB050117a: Radio Observations
  82. GRB050117a: Refined analysis
  83. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  84. GRB050117b: Swift-BAT detection of a weak burst
  85. GRB050117: optical observation
  86. GRB 050117, I-band observations
  87. GRB 050117: Optical observation
  88. GRB050117: Refined XRT position
  89. GRB050117: MASTER optical observations
  90. MASTER:GRB050117 SWIFT
  91. GRB050117: Swift-BAT detection of a long multi-peaked burst
  92. GRB050117: Swift XRT Position
  93. SGR1806-20: Swift-BAT observations of two additional bursts
  94. SGR 1806-20, RHESSI observations of the 041227 giant flare
  95. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  96. GRB 041217: Optical observations
  97. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  98. GRB041228: ROTSE-III Optical Observations
  99. GRB041228: Swift-BAT detection of a burst
  100. GRB041219; RXTE ASM Observations

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