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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"

28057 results found.

  1. GRB 100925A / MAXI J1659-152: BOOTES-2/TELMA and IAC80 optical observations
  2. GRB 100925A: Nearby DSS Source - SN-GRB or new Galactic transient?
  3. GRB100925A UVOT afterglow
  4. GRB 100924A: GROND detection of an optical/NIR afterglow
  5. GRB 100925A: Swift detection of a burst
  6. GRB 100924A: Swift-BAT refined analysis
  7. GRB 100917A: TAROT La Silla observatory optical observations
  8. GRB 100915A: TAROT Calern observatory optical observations
  9. GRB100906A: Ashra-1 observation of early optical emission
  10. GRB 100916A: Fermi GBM detection
  11. GRB 100917A: Swift-BAT refined analysis
  12. GRB 100917A: Swift detection of a burst
  13. GRB100915A: MITSuME Ishigakijima Optical upper limits
  14. GRB 100915B: GRT Optical Observation
  15. GRB 100915A: GRT Optical Observation
  16. GRB 100915B: Fermi GBM observation
  17. GRB 100915A: Correction to Swift-BAT refined analysis
  18. GRB 100915A: Swift/UVOT Upper Limits
  19. GRB 100915A: Swift-BAT refined analysis
  20. GRB 100915A: Swift-XRT refined analysis
  21. GRB 100915A: Enhanced Swift-XRT position
  22. GRB 100915B: a long GRB detected by INTEGRAL
  23. GRB 100915A: Swift detection of a likely burst
  24. GRB 100910A: Fermi GBM detection
  25. Swift BAT Trigger 433953 probably not a GRB
  26. GRB100909A: MITSuME Ishigakijima Optical upper limits
  27. GRB 100909A: Swift/UVOT observations
  28. GRB 100901A: errata of GRB name in GCN 11270
  29. GRB 100909A: Swift-XRT refined analysis
  30. GRB 100906A: optical observations at Mt.Terskol
  31. GRB 100901A: optical observation in Maidanak, break confirmation
  32. GRB 100909A: Faulkes Telescope North afterglow candidate
  33. GRB 100902A : Confirmation of afterglow and re-brightening with CFHT r’-band imaging
  34. GRB 100909A: Swift target of opportunity observation
  35. GRB100906A: detection at 15GHz
  36. GRB100901A: IAO optical upper limits at 4 days after the burst
  37. GRB100906A: R band observations
  38. GRB100906A: non-detection at 15GHz
  39. GRB100906A: Optical observations at IAO
  40. GRB 100906A: Fermi GBM observation
  41. GRB 100906A: Swift-XRT refined analysis
  42. GRB 100906A: Enhanced Swift-XRT position
  43. GRB 100906A: Swift/UVOT Observations
  44. GRB100906A: MITSuME Okayama Optical Observation
  45. GRB 100905A: Swift/UVOT Upper Limits
  46. GRB 100901A: TLS observations, SDSS calibration, decay slope
  47. GRB 100906A: MASTER preliminary prompt+afterglow lc
  48. GRB 100906A: Swift-BAT refined analysis
  49. GRB 100906A: Swift detection of a burst with an optical afterglow
  50. GRB 100829A: MASTER optical observations
  51. GRB100905A: Optical upper limits at IAO
  52. GRB100905A: MITSuME Okayama optical upper limits
  53. GRB 100905A: Swift-XRT refined analysis.
  54. GRB100905A: 1.5m OSN upper limit
  55. GRB 100905A: Enhanced Swift-XRT position
  56. GRB 100905A: Swift-BAT refined analysis
  57. GRB 100905A: Faulkes Telescope North observations
  58. GRB 100905A: Swift detection of a burst
  59. GRB10901A: Murikabushi telescope observation at 3 days after the burst
  60. GRB 100901A: Submm observations from SMA
  61. GRB 100904A: Swift-BAT refined analysis
  62. GRB100902A: Optical upper limits at IAO
  63. GRB10901A: Optical observations at IAO
  64. GRB 100902A: Swift-BAT refined analysis
  65. IPN Triangulation of the very bright GRB 100829A
  66. GRB 100902A: Swift XRT refined analysis
  67. GRB 100902A: Swift/UVOT Upper Limits
  68. GRB 100902A: optical observation at Mt.Terskol
  69. GRB 100901A: optical observation at Mt.Terskol
  70. GRB100901A: MITSuME Okayama Optical Observation at 1 day after the burst
  71. GRB 100902A: Enhanced Swift-XRT position
  72. GRB 100901A: TLS Observations: Break?
  73. GRB 100901A: ISON-NM optical observations
  74. GRB 100902A: Faulkes Telescope South observations
  75. GRB 100902A: Swift detection of a burst
  76. GRB 100901A: Vega telescope optical afterglow observation
  77. Swift/UVOT Observations of GRB100901A
  78. GRB 100901A: SARA-N observations
  79. GRB 100901A: THO optical observations
  80. GRB100901A: MITSuME Okayama Optical Observation
  81. GRB 100901A: Swift-XRT Team refined analysis
  82. GRB 100901A - NOT optical observation
  83. GRB 100901A: Swift-BAT refined analysis
  84. GRB 100901A: Enhanced Swift-XRT position
  85. GRB 100901A: Swift detection of a burst with an optical afterglow
  86. GRB 100829.9: MASTER Optical Limits
  87. GRB 100823A: optical upper limit
  88. GRB 100814A: Maidanak optical observations
  89. GRB 100823A: optical observations
  90. GRB 100725B: Mondy optical upper limit
  91. GRB 100725B: Maidanak optical upper limit
  92. GRB100807A: R band observations
  93. GRB 100823A: Swift XRT refined analysis
  94. GRB 100823A - second epoch WHT observations
  95. GRB 100823A: TNG NIR observations
  96. GRB 100823A: Swift/UVOT Upper Limits
  97. GRB 100823A: WHT observations
  98. GRB 100823A: Swift-BAT refined analysis
  99. GRB 100823A: Enhanced Swift-XRT position
  100. GRB 100823A: Swift detection of a burst

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