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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"

21458 results found.

  1. GRB 050319: Swift-BAT refined analysis
  2. GRB050319,optical observation
  3. Swift Detection of GRB 050319
  4. GRB 050319: Detection of Possible Optical Counterpart
  5. GRB 050318: Swift/UVOT detection of afterglow emission
  6. GRB 050318: Magellan optical afterglow identification
  7. GRB050318: Swift XRT position
  8. Swift-BAT detection of GRB 050318
  9. GRB050223: analysis of the XMM-Newton observation
  10. GRB 050306: ROTSE-III early limits
  11. GRB 050315: Swift-BAT further refined analysis
  12. GRB050315: Radio afterglow
  13. GRB 050315: Optical afterglow identification
  14. GRB050315: Swift-BAT Refined analysis
  15. Non-detection of GRB050315 in ATCA Radio Observations
  16. GRB 050315: Swift XRT Position
  17. GRB 050315: Early Observations with Swift/UVOT
  18. Swift-BAT detection of GRB 050315
  19. GRB050223: No XMM-Newton OM detection of afterglow emission
  20. GRB 050306: Radio Observations
  21. GRB050309: CONCAM pre-trigger and trigger coincident optical
  22. GRB 050306: optical afterglow
  23. GRB 050126: Redshift determination
  24. Swift-BAT trigger 107873: No Swift XRT counterpart
  25. GRB 050306: Confirmation of X-ray afterglow
  26. GRB 050309, Early optical limits from RAPTOR
  27. GRB050309: Early optical limit from P60
  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 050219b: candidate NIR afterglow
  40. GRB 050223: optical observations
  41. GRB050223 XMM-Newton observation
  42. INTEGRAL detection of GRB 050223
  43. GRB050223: No Swift UVOT Detection of Afterglow Emission
  44. GRB050223: ROTSE-III Optical Observations
  45. GRB 050223 Swift/BAT detection of a burst
  46. GRB 050223: Swift XRT Position
  47. GRB050219b: CORRECTION to time of UVOT observations
  48. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  49. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  50. GRB 050219b: CORRECTION to refined XRT position
  51. GRB 050219a: Optical observations from LCO
  52. GRB 050219b: Optical and near-IR observations from LCO
  53. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  54. GRB 050219b: Refined XRT position
  55. GRB 050219b: Swift-BAT detection of a burst
  56. GRB 050219b: CORRECTION: Swift XRT Position
  57. GRB 050219b: Swift XRT Position
  58. GRB 050219a, optical observations
  59. GRB 050219a: Refined XRT position
  60. GRB050219a: No Swift UVOT Detection of Afterglow Emission
  61. GRB 050219: Swift-BAT detection of a burst
  62. GRB050215b: Swift UVOT Detection of Afterglow Emission
  63. GRB 050219: Prompt X-ray position
  64. GRB 050215B: Radio Observations
  65. GRB 050215b: XRT confirmation of IR afterglow candidate
  66. GRB050215b: P60 Optical Observations
  67. GRB 050215b: Swift XRT Source Variability
  68. GRB 050215B: candidate afterglow
  69. GRB 050215b : Lulin follow-up observation
  70. GRB 050215b, BOOTES-2 simultaneous optical observations
  71. GRB 050215B: UKIRT K-band imaging
  72. GRB 050215b: Swift XRT Observations
  73. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  74. GRB050215a: No Swift UVOT Detection of Afterglow Emission
  75. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  76. GRB050215B: ROTSE-III optical observations
  77. GRB050215A: ROTSE-III Optical Observations
  78. short/hard GRB 050202, optical observations
  79. GRB 050128: Radio observations
  80. Further analysis of the short Swift-BAT GRB 050202
  81. GRB 050202: Second epoch radio observations
  82. GRB050202: Radio Observations
  83. GRB 050202: Short burst detected by Swift-BAT
  84. GRB 050128 Optical observation with REM
  85. SGR1806-20: Swift-BAT detection of a large normal burst
  86. GRB050128: Faulkes Telescope South observations
  87. GRB 050128: near-infrared observations with REM
  88. GRB050128,optical observations
  89. GRB 050126: A NIR afterglow candidate in the revised XRT error circle
  90. GRB050126: Updated Swift XRT Position
  91. GRB 050126: Radio Observations
  92. GRB050128 Swift-BAT observations
  93. GRB 050128: Swift XRT prompt afterglow position
  94. GRB 050124: K-band afterglow observations
  95. GRB050126: MASTER optical limit for KECK OT
  96. GRB050126: Burst Parameters Measured by BAT
  97. GRB050126: MASTER optical observations
  98. GRB 050126: Detection of NIR afterglow with Keck/NIRC
  99. GRB 050126: Prompt XRT detection and localization
  100. GRB 050124: NIR afterglow confirmed with Keck/NIRC

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