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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"

19595 results found.

  1. GRB 101020A: Swift detection of a burst
  2. GRB 101017A: Swift XRT refined analysis
  3. GRB 101017A: Swift/UVOT Observations
  4. GRB 101008A: optical observations
  5. Konus-Wind observation of GRB 101017A
  6. GRB 101017A: Enhanced Swift-XRT position
  7. GRB 101017A: Swift-BAT refined analysis
  8. GRB 101017A: ROTSE-III Optical Limits
  9. GRB 101017A: Swift detection of a burst with optical counterpart
  10. GRB 101011A: Fermi GBM detection
  11. GRB 101011A: BOOTES-3 Upper Limit
  12. GRB 100906A: D50 optical detection
  13. GRB 100902A: D50 optical limit
  14. GRB 101011A: Swift/UVOT observations
  15. GRB 101011A, GROND upper limits
  16. GRB 101011A: Zadko observatory - Gingin optical observations
  17. GRB 101011A: XRT Refined Analysis
  18. GRB 101011A: Swift/UVOT Observations of a Possible Optical Afterglow
  19. GRB 101011A: Enhanced Swift-XRT position
  20. GRB 101011A: Swift-BAT refined analysis
  21. GRB 101011A: Swift detection of a burst
  22. GRB 101008A: Fermi GBM observation
  23. GRB 101008A: MASTER prompt optical observations
  24. GRB 101008A: Swift-BAT refined analysis
  25. GRB101008A, GROND detection of a fading afterglow
  26. GRB 101008A: Swift-XRT refined analysis
  27. GRB 100915 optical upper limit
  28. GRB 101008: Swift/UVOT Upper Limits
  29. GRB 101008A: Enhanced Swift-XRT position
  30. GRB 101008A: 1.23m CAHA optical observations
  31. GRB 101008A: Swift/XRT Detection of an Afterglow with no UVOT Counterpart
  32. GRB 101008A: Swift detection of a burst
  33. Refined analysis shows Swift Trigger 435520 is not a GRB
  34. Swift Trigger 435520 is probably not a GRB
  35. GRB 100924A: Suzaku WAM observation of the prompt emission
  36. GRB 100928A, Swift-BAT refined analysis
  37. GRB 100924A: Fermi GBM observation
  38. GRB 100928A: Swift detection of a burst
  39. GRB 100925A / MAXI J1659-152: WSRT Radio and Polarization Detection
  40. GRB100925A/MAXI J1659-152: Galactic origin from SED analysis
  41. GRB 100925A / MAXI J1659-152: BOOTES-2/TELMA and IAC80 optical observations
  42. MAXI J1659-152: Swift-BAT refined analysis (triggers 434928 and 434931)
  43. GRB 100925A: Nearby DSS Source - SN-GRB or new Galactic transient?
  44. GRB100925A UVOT afterglow
  45. GRB 100924A: GROND detection of an optical/NIR afterglow
  46. GRB 100925A: Swift detection of a burst
  47. GRB 100924A: Swift-BAT refined analysis
  48. GRB 100924A: Swift detection of a burst
  49. GRB 100917A: TAROT La Silla observatory optical observations
  50. GRB 100915A: TAROT Calern observatory optical observations
  51. GRB100906A: Ashra-1 observation of early optical emission
  52. GRB 100917A: Swift-BAT refined analysis
  53. GRB 100917A: Swift detection of a burst
  54. GRB 100915A: GRT Optical Observation
  55. GRB 100915A: Correction to Swift-BAT refined analysis
  56. GRB 100915A: Swift/UVOT Upper Limits
  57. GRB 100915A: Swift-BAT refined analysis
  58. GRB 100915A: Swift-XRT refined analysis
  59. GRB 100915A: Enhanced Swift-XRT position
  60. GRB 100915A: Swift detection of a likely burst
  61. Swift-BAT trigger 433953 is not a burst
  62. Swift BAT Trigger 433953 probably not a GRB
  63. GRB 100909A: Swift/UVOT observations
  64. GRB 100901A: optical observations in Mondy and R-light curve
  65. GRB 100909A: Swift-XRT refined analysis
  66. GRB 100906A: optical observations at Mt.Terskol
  67. GRB 100901A: optical observation in Maidanak, break confirmation
  68. GRB 100909A: Faulkes Telescope North afterglow candidate
  69. GRB 100909A: ROTSE-III Optical Limits
  70. GRB 100902A : Confirmation of afterglow and re-brightening with CFHT r’-band imaging
  71. GRB 100909A: Swift target of opportunity observation
  72. EVLA detection of radio afterglow of GRB100901A
  73. GRB 100901A: CrAO optical observations
  74. GRB100906A: R band observations
  75. Konus-Wind observation of GRB 100906A
  76. GRB 100906A: Fermi GBM observation
  77. GRB 100901A: TLS Detection at 5.5 days
  78. GRB 100906A: Swift-XRT refined analysis
  79. GRB 100906A: Enhanced Swift-XRT position
  80. GRB 100906A: Swift/UVOT Observations
  81. GRB 100906A: TLS Multicolor Observations
  82. GRB 100905A: Swift/UVOT Upper Limits
  83. GRB 100901A: ISON-NM optical observations
  84. GRB 100906A: Swift-BAT refined analysis
  85. GRB 100906A: MASTER preliminary polarization prompt light curve
  86. GRB 100906A : Faulkes Telescope North optical observations
  87. GRB 100906A: MASTER early OT observations
  88. GRB 100906A: Swift detection of a burst with an optical afterglow
  89. GRB 100905A: Swift-XRT refined analysis.
  90. GRB 100905A: Enhanced Swift-XRT position
  91. GRB 100905A: Swift-BAT refined analysis
  92. GRB100904A: BOOTES-3 Upper Limit
  93. GRB 100905A: MASTER Prompt Optical Observations
  94. GRB 100905A: Faulkes Telescope North observations
  95. GRB 100905A: Swift detection of a burst
  96. GRB 100904A: Swift-BAT refined analysis
  97. GRB 100904A: Swift detection of a burst
  98. GRB 100902A: Swift-BAT refined analysis
  99. GRB 100901A: optical observation at Mt.Terskol
  100. GRB 100901A: multicolor photometry at Mt.Terskol

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