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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"

18541 results found.

  1. GRB050319: BR optical photometry
  2. GRB 050318: SWIFT-UVOT refined analysis
  3. GRB 050319: Swift-BAT refined analysis
  4. GRB050319,optical observation
  5. Swift Detection of GRB 050319
  6. GRB 050319: Detection of Possible Optical Counterpart
  7. GRB 050318: Swift/UVOT detection of afterglow emission
  8. GRB050318: Swift XRT position
  9. Swift-BAT detection of GRB 050318
  10. GRB050223: analysis of the XMM-Newton observation
  11. GRB 050306: ROTSE-III early limits
  12. GRB 050315: Swift-BAT further refined analysis
  13. GRB050315: Swift-BAT Refined analysis
  14. Non-detection of GRB050315 in ATCA Radio Observations
  15. GRB 050315: Swift XRT Position
  16. GRB 050315: Early Observations with Swift/UVOT
  17. Swift-BAT detection of GRB 050315
  18. GRB050223: No XMM-Newton OM detection of afterglow emission
  19. GRB050309: CONCAM pre-trigger and trigger coincident optical
  20. GRB 050126: Redshift determination
  21. Swift-BAT trigger 107873: No Swift XRT counterpart
  22. GRB 050306: Confirmation of X-ray afterglow
  23. GRB 050309, Early optical limits from RAPTOR
  24. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  25. GRB 050309 : Lulin R-band observation
  26. Swift 107873: P60 Optical Observations
  27. GRB 050306: CORRECTION to date of observation
  28. GRB 050306: No Swift UVOT Optical Counterpart Detected
  29. GRB 050306: Possible X-ray Afterglow Position from the Swift
  30. Swift trigger 107518: optical observation
  31. GRB 050306,optical observation
  32. GRB 050306: Swift-BAT detection of a long burst
  33. GRB050215B: Late-Time Swift UVOT Observations
  34. PROMPT VRcIc Observations of GRB 050223
  35. GRB 050223: optical observations
  36. GRB050223 XMM-Newton observation
  37. INTEGRAL detection of GRB 050223
  38. GRB050223: No Swift UVOT Detection of Afterglow Emission
  39. GRB050223: ROTSE-III Optical Observations
  40. GRB 050223 Swift/BAT detection of a burst
  41. GRB 050223: Swift XRT Position
  42. GRB050219b: CORRECTION to time of UVOT observations
  43. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  44. GRB 050219b: CORRECTION to refined XRT position
  45. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  46. GRB 050219b: Refined XRT position
  47. GRB 050219b: Swift-BAT detection of a burst
  48. GRB 050219b: CORRECTION: Swift XRT Position
  49. GRB 050219b: Swift XRT Position
  50. GRB 050219a, optical observations
  51. GRB 050219a: Refined XRT position
  52. GRB050219a: No Swift UVOT Detection of Afterglow Emission
  53. GRB 050219: Swift-BAT detection of a burst
  54. GRB050215b: Swift UVOT Detection of Afterglow Emission
  55. GRB 050219: Prompt X-ray position
  56. GRB 050215b: XRT confirmation of IR afterglow candidate
  57. GRB050215b: P60 Optical Observations
  58. GRB 050215b: Swift XRT Source Variability
  59. GRB 050215B: candidate afterglow
  60. GRB 050215b : Lulin follow-up observation
  61. GRB 050215b, BOOTES-2 simultaneous optical observations
  62. GRB 050215B: UKIRT K-band imaging
  63. GRB 050215b: Swift XRT Observations
  64. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  65. GRB050215a: No Swift UVOT Detection of Afterglow Emission
  66. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  67. GRB050215B: ROTSE-III optical observations
  68. GRB050215A: ROTSE-III Optical Observations
  69. short/hard GRB 050202, optical observations
  70. GRB 050128: Radio observations
  71. Further analysis of the short Swift-BAT GRB 050202
  72. GRB 050202: Second epoch radio observations
  73. GRB050202: Radio Observations
  74. GRB 050202: Short burst detected by Swift-BAT
  75. SGR1806-20: Swift-BAT detection of a large normal burst
  76. GRB050128: Faulkes Telescope South observations
  77. GRB050128,optical observations
  78. GRB050126: Updated Swift XRT Position
  79. GRB 050126: Radio Observations
  80. GRB050128 Swift-BAT observations
  81. GRB 050128: Swift XRT prompt afterglow position
  82. GRB 050124: K-band afterglow observations
  83. GRB050126: MASTER optical limit for KECK OT
  84. GRB050126: Burst Parameters Measured by BAT
  85. GRB050126: MASTER optical observations
  86. GRB 050126: Prompt XRT detection and localization
  87. GRB050124: No Swift UVOT Detection of Afterglow Emission
  88. GRB 050117a: Radio Observations
  89. GRB050124,optical observation
  90. GRB050124: Updated Swift XRT Position and Fluxes
  91. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  92. GRB050124: Refined BAT position, spectral and fluence information
  93. GRB050124: Swift-BAT position of a double-peaked burst
  94. GRB050117a: Radio Observations
  95. GRB050117a: Refined analysis
  96. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  97. GRB050117b: Swift-BAT detection of a weak burst
  98. GRB050117: optical observation
  99. GRB 050117, I-band observations
  100. GRB 050117: Optical observation

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