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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"

19147 results found.

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

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