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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"

18745 results found.

  1. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  2. GRB 050319 R band observations
  3. GRB 050319: Swift-UVOT detection of the afterglow
  4. GRB 050315: Variability Analysis of Swift BAT Time History
  5. GRB050319: BR optical photometry
  6. GRB 050318: SWIFT-UVOT refined analysis
  7. GRB 050319: Swift-BAT refined analysis
  8. GRB050319,optical observation
  9. Swift Detection of GRB 050319
  10. GRB 050319: Detection of Possible Optical Counterpart
  11. GRB 050318: Swift/UVOT detection of afterglow emission
  12. GRB050318: Swift XRT position
  13. Swift-BAT detection of GRB 050318
  14. GRB050223: analysis of the XMM-Newton observation
  15. GRB 050306: ROTSE-III early limits
  16. GRB 050315: Swift-BAT further refined analysis
  17. GRB050315: Swift-BAT Refined analysis
  18. Non-detection of GRB050315 in ATCA Radio Observations
  19. GRB 050315: Swift XRT Position
  20. GRB 050315: Early Observations with Swift/UVOT
  21. Swift-BAT detection of GRB 050315
  22. GRB050223: No XMM-Newton OM detection of afterglow emission
  23. GRB050309: CONCAM pre-trigger and trigger coincident optical
  24. GRB 050126: Redshift determination
  25. Swift-BAT trigger 107873: No Swift XRT counterpart
  26. GRB 050306: Confirmation of X-ray afterglow
  27. GRB 050309, Early optical limits from RAPTOR
  28. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  29. GRB 050309 : Lulin R-band observation
  30. Swift 107873: P60 Optical Observations
  31. GRB 050306: CORRECTION to date of observation
  32. GRB 050306: No Swift UVOT Optical Counterpart Detected
  33. GRB 050306: Possible X-ray Afterglow Position from the Swift
  34. Swift trigger 107518: optical observation
  35. GRB 050306,optical observation
  36. GRB 050306: Swift-BAT detection of a long burst
  37. GRB050215B: Late-Time Swift UVOT Observations
  38. PROMPT VRcIc Observations of GRB 050223
  39. GRB 050223: optical observations
  40. GRB050223 XMM-Newton observation
  41. INTEGRAL detection of GRB 050223
  42. GRB050223: No Swift UVOT Detection of Afterglow Emission
  43. GRB050223: ROTSE-III Optical Observations
  44. GRB 050223 Swift/BAT detection of a burst
  45. GRB 050223: Swift XRT Position
  46. GRB050219b: CORRECTION to time of UVOT observations
  47. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  48. GRB 050219b: CORRECTION to refined XRT position
  49. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  50. GRB 050219b: Refined XRT position
  51. GRB 050219b: Swift-BAT detection of a burst
  52. GRB 050219b: CORRECTION: Swift XRT Position
  53. GRB 050219b: Swift XRT Position
  54. GRB 050219a, optical observations
  55. GRB 050219a: Refined XRT position
  56. GRB050219a: No Swift UVOT Detection of Afterglow Emission
  57. GRB 050219: Swift-BAT detection of a burst
  58. GRB050215b: Swift UVOT Detection of Afterglow Emission
  59. GRB 050219: Prompt X-ray position
  60. GRB 050215b: XRT confirmation of IR afterglow candidate
  61. GRB050215b: P60 Optical Observations
  62. GRB 050215b: Swift XRT Source Variability
  63. GRB 050215B: candidate afterglow
  64. GRB 050215b : Lulin follow-up observation
  65. GRB 050215b, BOOTES-2 simultaneous optical observations
  66. GRB 050215B: UKIRT K-band imaging
  67. GRB 050215b: Swift XRT Observations
  68. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  69. GRB050215a: No Swift UVOT Detection of Afterglow Emission
  70. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  71. GRB050215B: ROTSE-III optical observations
  72. GRB050215A: ROTSE-III Optical Observations
  73. short/hard GRB 050202, optical observations
  74. GRB 050128: Radio observations
  75. Further analysis of the short Swift-BAT GRB 050202
  76. GRB 050202: Second epoch radio observations
  77. GRB050202: Radio Observations
  78. GRB 050202: Short burst detected by Swift-BAT
  79. SGR1806-20: Swift-BAT detection of a large normal burst
  80. GRB050128: Faulkes Telescope South observations
  81. GRB050128,optical observations
  82. GRB050126: Updated Swift XRT Position
  83. GRB 050126: Radio Observations
  84. GRB050128 Swift-BAT observations
  85. GRB 050128: Swift XRT prompt afterglow position
  86. GRB 050124: K-band afterglow observations
  87. GRB050126: MASTER optical limit for KECK OT
  88. GRB050126: Burst Parameters Measured by BAT
  89. GRB050126: MASTER optical observations
  90. GRB 050126: Prompt XRT detection and localization
  91. GRB050124: No Swift UVOT Detection of Afterglow Emission
  92. GRB 050117a: Radio Observations
  93. GRB050124,optical observation
  94. GRB050124: Updated Swift XRT Position and Fluxes
  95. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  96. GRB050124: Refined BAT position, spectral and fluence information
  97. GRB050124: Swift-BAT position of a double-peaked burst
  98. GRB050117a: Radio Observations
  99. GRB050117a: Refined analysis
  100. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations

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