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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"

21455 results found.

  1. GRB 050319: Detection of Possible Optical Counterpart
  2. GRB 050318: Swift/UVOT detection of afterglow emission
  3. GRB 050318: Magellan optical afterglow identification
  4. GRB050318: Swift XRT position
  5. Swift-BAT detection of GRB 050318
  6. GRB050223: analysis of the XMM-Newton observation
  7. GRB 050306: ROTSE-III early limits
  8. GRB 050315: Swift-BAT further refined analysis
  9. GRB050315: Radio afterglow
  10. GRB 050315: Optical afterglow identification
  11. GRB050315: Swift-BAT Refined analysis
  12. Non-detection of GRB050315 in ATCA Radio Observations
  13. GRB 050315: Swift XRT Position
  14. GRB 050315: Early Observations with Swift/UVOT
  15. Swift-BAT detection of GRB 050315
  16. GRB050223: No XMM-Newton OM detection of afterglow emission
  17. GRB 050306: Radio Observations
  18. GRB050309: CONCAM pre-trigger and trigger coincident optical
  19. GRB 050306: optical afterglow
  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. GRB050309: Early optical limit from P60
  25. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  26. GRB 050309 : Lulin R-band observation
  27. Swift 107873: P60 Optical Observations
  28. GRB 050306: CORRECTION to date of observation
  29. GRB 050306: No Swift UVOT Optical Counterpart Detected
  30. GRB 050306: Possible X-ray Afterglow Position from the Swift
  31. Swift trigger 107518: optical observation
  32. GRB 050306,optical observation
  33. GRB 050306: Swift-BAT detection of a long burst
  34. GRB050215B: Late-Time Swift UVOT Observations
  35. PROMPT VRcIc Observations of GRB 050223
  36. GRB 050219b: candidate NIR afterglow
  37. GRB 050223: optical observations
  38. GRB050223 XMM-Newton observation
  39. INTEGRAL detection of GRB 050223
  40. GRB050223: No Swift UVOT Detection of Afterglow Emission
  41. GRB050223: ROTSE-III Optical Observations
  42. GRB 050223 Swift/BAT detection of a burst
  43. GRB 050223: Swift XRT Position
  44. GRB050219b: CORRECTION to time of UVOT observations
  45. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  46. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  47. GRB 050219b: CORRECTION to refined XRT position
  48. GRB 050219a: Optical observations from LCO
  49. GRB 050219b: Optical and near-IR observations from LCO
  50. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  51. GRB 050219b: Refined XRT position
  52. GRB 050219b: Swift-BAT detection of a burst
  53. GRB 050219b: CORRECTION: Swift XRT Position
  54. GRB 050219b: Swift XRT Position
  55. GRB 050219a, optical observations
  56. GRB 050219a: Refined XRT position
  57. GRB050219a: No Swift UVOT Detection of Afterglow Emission
  58. GRB 050219: Swift-BAT detection of a burst
  59. GRB050215b: Swift UVOT Detection of Afterglow Emission
  60. GRB 050219: Prompt X-ray position
  61. GRB 050215B: Radio Observations
  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. GRB 050128 Optical observation with REM
  82. SGR1806-20: Swift-BAT detection of a large normal burst
  83. GRB050128: Faulkes Telescope South observations
  84. GRB 050128: near-infrared observations with REM
  85. GRB050128,optical observations
  86. GRB 050126: A NIR afterglow candidate in the revised XRT error circle
  87. GRB050126: Updated Swift XRT Position
  88. GRB 050126: Radio Observations
  89. GRB050128 Swift-BAT observations
  90. GRB 050128: Swift XRT prompt afterglow position
  91. GRB 050124: K-band afterglow observations
  92. GRB050126: MASTER optical limit for KECK OT
  93. GRB050126: Burst Parameters Measured by BAT
  94. GRB050126: MASTER optical observations
  95. GRB 050126: Detection of NIR afterglow with Keck/NIRC
  96. GRB 050126: Prompt XRT detection and localization
  97. GRB 050124: NIR afterglow confirmed with Keck/NIRC
  98. GRB050124: No Swift UVOT Detection of Afterglow Emission
  99. GRB 050117a: Radio Observations
  100. GRB 050124: NIR Candidates from Keck/NIRC

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