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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"

19608 results found.

  1. GRB 101024A: Zadko observatory - Gingin. Optical observations
  2. GRB 101024A: Fermi GBM observation
  3. GRB 101023A: Fermi GBM observation
  4. GRB101024A: Swift/UVOT
  5. GRB 101024A: Swift-BAT refined analysis
  6. GRB 101024A: Enhanced Swift-XRT position
  7. Swift/UVOT observations of GRB101023A
  8. GRB 101024A: Swift detection of a burst with an optical afterglow
  9. GGRB 101023A: GROND detection of the optical-NIR afterglow
  10. GRB 101023A: Swift-XRT Team Refined Analysis
  11. GRB 101023A: Swift-BAT refined analysis
  12. GRB 101023A: Enhanced Swift-XRT position
  13. GRB 101023A: Swift detection of a burst
  14. GRB 101020A: MASTER prompt and afterglow limit
  15. GRB 101020A: MASTER polarization optical observations
  16. GRB 101020A, Swift-BAT refined analysis
  17. GRB 101020A: Swift detection of a burst
  18. GRB 101017A: Swift XRT refined analysis
  19. GRB 101017A: Swift/UVOT Observations
  20. GRB 101008A: optical observations
  21. Konus-Wind observation of GRB 101017A
  22. GRB 101017A: Enhanced Swift-XRT position
  23. GRB 101017A: Swift-BAT refined analysis
  24. GRB 101017A: ROTSE-III Optical Limits
  25. GRB 101017A: Swift detection of a burst with optical counterpart
  26. GRB 101011A: Fermi GBM detection
  27. GRB 101011A: BOOTES-3 Upper Limit
  28. GRB 100906A: D50 optical detection
  29. GRB 100902A: D50 optical limit
  30. GRB 101011A: Swift/UVOT observations
  31. GRB 101011A, GROND upper limits
  32. GRB 101011A: Zadko observatory - Gingin optical observations
  33. GRB 101011A: XRT Refined Analysis
  34. GRB 101011A: Swift/UVOT Observations of a Possible Optical Afterglow
  35. GRB 101011A: Enhanced Swift-XRT position
  36. GRB 101011A: Swift-BAT refined analysis
  37. GRB 101011A: Swift detection of a burst
  38. GRB 101008A: Fermi GBM observation
  39. GRB 101008A: MASTER prompt optical observations
  40. GRB 101008A: Swift-BAT refined analysis
  41. GRB101008A, GROND detection of a fading afterglow
  42. GRB 101008A: Swift-XRT refined analysis
  43. GRB 100915 optical upper limit
  44. GRB 101008: Swift/UVOT Upper Limits
  45. GRB 101008A: Enhanced Swift-XRT position
  46. GRB 101008A: 1.23m CAHA optical observations
  47. GRB 101008A: Swift/XRT Detection of an Afterglow with no UVOT Counterpart
  48. GRB 101008A: Swift detection of a burst
  49. Refined analysis shows Swift Trigger 435520 is not a GRB
  50. Swift Trigger 435520 is probably not a GRB
  51. GRB 100924A: Suzaku WAM observation of the prompt emission
  52. GRB 100928A, Swift-BAT refined analysis
  53. GRB 100924A: Fermi GBM observation
  54. GRB 100928A: Swift detection of a burst
  55. GRB 100925A / MAXI J1659-152: WSRT Radio and Polarization Detection
  56. GRB100925A/MAXI J1659-152: Galactic origin from SED analysis
  57. GRB 100925A / MAXI J1659-152: BOOTES-2/TELMA and IAC80 optical observations
  58. MAXI J1659-152: Swift-BAT refined analysis (triggers 434928 and 434931)
  59. GRB 100925A: Nearby DSS Source - SN-GRB or new Galactic transient?
  60. GRB100925A UVOT afterglow
  61. GRB 100924A: GROND detection of an optical/NIR afterglow
  62. GRB 100925A: Swift detection of a burst
  63. GRB 100924A: Swift-BAT refined analysis
  64. GRB 100924A: Swift detection of a burst
  65. GRB 100917A: TAROT La Silla observatory optical observations
  66. GRB 100915A: TAROT Calern observatory optical observations
  67. GRB100906A: Ashra-1 observation of early optical emission
  68. GRB 100917A: Swift-BAT refined analysis
  69. GRB 100917A: Swift detection of a burst
  70. GRB 100915A: GRT Optical Observation
  71. GRB 100915A: Correction to Swift-BAT refined analysis
  72. GRB 100915A: Swift/UVOT Upper Limits
  73. GRB 100915A: Swift-BAT refined analysis
  74. GRB 100915A: Swift-XRT refined analysis
  75. GRB 100915A: Enhanced Swift-XRT position
  76. GRB 100915A: Swift detection of a likely burst
  77. Swift-BAT trigger 433953 is not a burst
  78. Swift BAT Trigger 433953 probably not a GRB
  79. GRB 100909A: Swift/UVOT observations
  80. GRB 100901A: optical observations in Mondy and R-light curve
  81. GRB 100909A: Swift-XRT refined analysis
  82. GRB 100906A: optical observations at Mt.Terskol
  83. GRB 100901A: optical observation in Maidanak, break confirmation
  84. GRB 100909A: Faulkes Telescope North afterglow candidate
  85. GRB 100909A: ROTSE-III Optical Limits
  86. GRB 100902A : Confirmation of afterglow and re-brightening with CFHT r’-band imaging
  87. GRB 100909A: Swift target of opportunity observation
  88. EVLA detection of radio afterglow of GRB100901A
  89. GRB 100901A: CrAO optical observations
  90. GRB100906A: R band observations
  91. Konus-Wind observation of GRB 100906A
  92. GRB 100906A: Fermi GBM observation
  93. GRB 100901A: TLS Detection at 5.5 days
  94. GRB 100906A: Swift-XRT refined analysis
  95. GRB 100906A: Enhanced Swift-XRT position
  96. GRB 100906A: Swift/UVOT Observations
  97. GRB 100906A: TLS Multicolor Observations
  98. GRB 100905A: Swift/UVOT Upper Limits
  99. GRB 100901A: ISON-NM optical observations
  100. GRB 100906A: Swift-BAT refined analysis

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