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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"

18430 results found.

  1. GRB 101117B: Swift-XRT refined analysis
  2. GRB101114A: Swift/UVOT Upper Limits
  3. GRB 101114A: Confirmation of the X-ray afterglow
  4. GRB 101117B: Swift-BAT refined analysis
  5. GRB 101117B: Enhanced Swift-XRT position
  6. GRB 101117B: Swift/UVOT Discovery of an Optical Afterglow
  7. GRB 101117B: Swift detection of a burst
  8. GRB 101114A: GROND Upper limits
  9. GRB 101114A: Swift-XRT candidate afterglow detection and analysis
  10. GRB 101114A, Swift-BAT GRB detected by ground processing
  11. GRB 101112A - XRT source detection/analysis
  12. GRB 101030A : MOA optical observation
  13. GRB 101030A : Swift XRT refined analysis
  14. GRB 101030A: Swift/UVOT Upper Limits
  15. GRB 101030A: Swift-BAT refined analysis
  16. GRB 101030A: Enhanced Swift-XRT position
  17. GRB 101030A: Swift detection of a burst
  18. Konus-Wind observation of GRB 101023A
  19. GRB 101024A: Swift XRT refined analysis
  20. GRB 101024A: Zadko observatory - Gingin. Optical observations
  21. GRB 101024A: Fermi GBM observation
  22. GRB 101023A: Fermi GBM observation
  23. GRB101024A: Swift/UVOT
  24. GRB 101024A: Swift-BAT refined analysis
  25. GRB 101024A: Enhanced Swift-XRT position
  26. Swift/UVOT observations of GRB101023A
  27. GRB 101024A: Swift detection of a burst with an optical afterglow
  28. GGRB 101023A: GROND detection of the optical-NIR afterglow
  29. GRB 101023A: Swift-XRT Team Refined Analysis
  30. GRB 101023A: Swift-BAT refined analysis
  31. GRB 101023A: Enhanced Swift-XRT position
  32. GRB 101023A: Swift detection of a burst
  33. GRB 101020A: MASTER prompt and afterglow limit
  34. GRB 101020A: MASTER polarization optical observations
  35. GRB 101020A, Swift-BAT refined analysis
  36. GRB 101020A: Swift detection of a burst
  37. GRB 101017A: Swift XRT refined analysis
  38. GRB 101017A: Swift/UVOT Observations
  39. GRB 101008A: optical observations
  40. Konus-Wind observation of GRB 101017A
  41. GRB 101017A: Enhanced Swift-XRT position
  42. GRB 101017A: Swift-BAT refined analysis
  43. GRB 101017A: ROTSE-III Optical Limits
  44. GRB 101017A: Swift detection of a burst with optical counterpart
  45. GRB 101011A: Fermi GBM detection
  46. GRB 101011A: BOOTES-3 Upper Limit
  47. GRB 100906A: D50 optical detection
  48. GRB 100902A: D50 optical limit
  49. GRB 101011A: Swift/UVOT observations
  50. GRB 101011A, GROND upper limits
  51. GRB 101011A: Zadko observatory - Gingin optical observations
  52. GRB 101011A: XRT Refined Analysis
  53. GRB 101011A: Swift/UVOT Observations of a Possible Optical Afterglow
  54. GRB 101011A: Enhanced Swift-XRT position
  55. GRB 101011A: Swift-BAT refined analysis
  56. GRB 101011A: Swift detection of a burst
  57. GRB 101008A: Fermi GBM observation
  58. GRB 101008A: MASTER prompt optical observations
  59. GRB 101008A: Swift-BAT refined analysis
  60. GRB101008A, GROND detection of a fading afterglow
  61. GRB 101008A: Swift-XRT refined analysis
  62. GRB 100915 optical upper limit
  63. GRB 101008: Swift/UVOT Upper Limits
  64. GRB 101008A: Enhanced Swift-XRT position
  65. GRB 101008A: 1.23m CAHA optical observations
  66. GRB 101008A: Swift/XRT Detection of an Afterglow with no UVOT Counterpart
  67. GRB 101008A: Swift detection of a burst
  68. Refined analysis shows Swift Trigger 435520 is not a GRB
  69. Swift Trigger 435520 is probably not a GRB
  70. GRB 100924A: Suzaku WAM observation of the prompt emission
  71. GRB 100928A, Swift-BAT refined analysis
  72. GRB 100924A: Fermi GBM observation
  73. GRB 100928A: Swift detection of a burst
  74. GRB 100925A / MAXI J1659-152: WSRT Radio and Polarization Detection
  75. GRB100925A/MAXI J1659-152: Galactic origin from SED analysis
  76. GRB 100925A / MAXI J1659-152: BOOTES-2/TELMA and IAC80 optical observations
  77. MAXI J1659-152: Swift-BAT refined analysis (triggers 434928 and 434931)
  78. GRB 100925A: Nearby DSS Source - SN-GRB or new Galactic transient?
  79. GRB100925A UVOT afterglow
  80. GRB 100924A: GROND detection of an optical/NIR afterglow
  81. GRB 100925A: Swift detection of a burst
  82. GRB 100924A: Swift-BAT refined analysis
  83. GRB 100924A: Swift detection of a burst
  84. GRB 100917A: TAROT La Silla observatory optical observations
  85. GRB 100915A: TAROT Calern observatory optical observations
  86. GRB100906A: Ashra-1 observation of early optical emission
  87. GRB 100917A: Swift-BAT refined analysis
  88. GRB 100917A: Swift detection of a burst
  89. GRB 100915A: GRT Optical Observation
  90. GRB 100915A: Correction to Swift-BAT refined analysis
  91. GRB 100915A: Swift/UVOT Upper Limits
  92. GRB 100915A: Swift-BAT refined analysis
  93. GRB 100915A: Swift-XRT refined analysis
  94. GRB 100915A: Enhanced Swift-XRT position
  95. GRB 100915A: Swift detection of a likely burst
  96. Swift-BAT trigger 433953 is not a burst
  97. Swift BAT Trigger 433953 probably not a GRB
  98. GRB 100909A: Swift/UVOT observations
  99. GRB 100901A: optical observations in Mondy and R-light curve
  100. GRB 100909A: Swift-XRT refined analysis

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