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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"

18651 results found.

  1. GRB050319, color indices
  2. GRB050319: RTT150 Optical Observations
  3. Swift-BAT detection of a bright outburst from SGR1806-20
  4. Swift-BAT trigger 112060 is not a real GRB
  5. GRB 050319: ROTSE-III Refined Analysis
  6. GRB 050318: Swift-BAT refined analysis
  7. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  8. GRB 050319 R band observations
  9. GRB 050319: Swift-UVOT detection of the afterglow
  10. GRB 050315: Variability Analysis of Swift BAT Time History
  11. GRB050319: BR optical photometry
  12. GRB 050318: SWIFT-UVOT refined analysis
  13. GRB 050319: Swift-BAT refined analysis
  14. GRB050319,optical observation
  15. Swift Detection of GRB 050319
  16. GRB 050319: Detection of Possible Optical Counterpart
  17. GRB 050318: Swift/UVOT detection of afterglow emission
  18. GRB050318: Swift XRT position
  19. Swift-BAT detection of GRB 050318
  20. GRB050223: analysis of the XMM-Newton observation
  21. GRB 050306: ROTSE-III early limits
  22. GRB 050315: Swift-BAT further refined analysis
  23. GRB050315: Swift-BAT Refined analysis
  24. Non-detection of GRB050315 in ATCA Radio Observations
  25. GRB 050315: Swift XRT Position
  26. GRB 050315: Early Observations with Swift/UVOT
  27. Swift-BAT detection of GRB 050315
  28. GRB050223: No XMM-Newton OM detection of afterglow emission
  29. GRB050309: CONCAM pre-trigger and trigger coincident optical
  30. GRB 050126: Redshift determination
  31. Swift-BAT trigger 107873: No Swift XRT counterpart
  32. GRB 050306: Confirmation of X-ray afterglow
  33. GRB 050309, Early optical limits from RAPTOR
  34. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  35. GRB 050309 : Lulin R-band observation
  36. Swift 107873: P60 Optical Observations
  37. GRB 050306: CORRECTION to date of observation
  38. GRB 050306: No Swift UVOT Optical Counterpart Detected
  39. GRB 050306: Possible X-ray Afterglow Position from the Swift
  40. Swift trigger 107518: optical observation
  41. GRB 050306,optical observation
  42. GRB 050306: Swift-BAT detection of a long burst
  43. GRB050215B: Late-Time Swift UVOT Observations
  44. PROMPT VRcIc Observations of GRB 050223
  45. GRB 050223: optical observations
  46. GRB050223 XMM-Newton observation
  47. INTEGRAL detection of GRB 050223
  48. GRB050223: No Swift UVOT Detection of Afterglow Emission
  49. GRB050223: ROTSE-III Optical Observations
  50. GRB 050223 Swift/BAT detection of a burst
  51. GRB 050223: Swift XRT Position
  52. GRB050219b: CORRECTION to time of UVOT observations
  53. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  54. GRB 050219b: CORRECTION to refined XRT position
  55. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  56. GRB 050219b: Refined XRT position
  57. GRB 050219b: Swift-BAT detection of a burst
  58. GRB 050219b: CORRECTION: Swift XRT Position
  59. GRB 050219b: Swift XRT Position
  60. GRB 050219a, optical observations
  61. GRB 050219a: Refined XRT position
  62. GRB050219a: No Swift UVOT Detection of Afterglow Emission
  63. GRB 050219: Swift-BAT detection of a burst
  64. GRB050215b: Swift UVOT Detection of Afterglow Emission
  65. GRB 050219: Prompt X-ray position
  66. GRB 050215b: XRT confirmation of IR afterglow candidate
  67. GRB050215b: P60 Optical Observations
  68. GRB 050215b: Swift XRT Source Variability
  69. GRB 050215B: candidate afterglow
  70. GRB 050215b : Lulin follow-up observation
  71. GRB 050215b, BOOTES-2 simultaneous optical observations
  72. GRB 050215B: UKIRT K-band imaging
  73. GRB 050215b: Swift XRT Observations
  74. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  75. GRB050215a: No Swift UVOT Detection of Afterglow Emission
  76. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  77. GRB050215B: ROTSE-III optical observations
  78. GRB050215A: ROTSE-III Optical Observations
  79. short/hard GRB 050202, optical observations
  80. GRB 050128: Radio observations
  81. Further analysis of the short Swift-BAT GRB 050202
  82. GRB 050202: Second epoch radio observations
  83. GRB050202: Radio Observations
  84. GRB 050202: Short burst detected by Swift-BAT
  85. SGR1806-20: Swift-BAT detection of a large normal burst
  86. GRB050128: Faulkes Telescope South observations
  87. GRB050128,optical observations
  88. GRB050126: Updated Swift XRT Position
  89. GRB 050126: Radio Observations
  90. GRB050128 Swift-BAT observations
  91. GRB 050128: Swift XRT prompt afterglow position
  92. GRB 050124: K-band afterglow observations
  93. GRB050126: MASTER optical limit for KECK OT
  94. GRB050126: Burst Parameters Measured by BAT
  95. GRB050126: MASTER optical observations
  96. GRB 050126: Prompt XRT detection and localization
  97. GRB050124: No Swift UVOT Detection of Afterglow Emission
  98. GRB 050117a: Radio Observations
  99. GRB050124,optical observation
  100. GRB050124: Updated Swift XRT Position and Fluxes

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