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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"

27769 results found.

  1. GRB 101008A: Fermi GBM observation
  2. GRB 101008A: MASTER prompt optical observations
  3. GRB 101008A: Swift-BAT refined analysis
  4. GRB101008A, GROND detection of a fading afterglow
  5. GRB 101008A: Swift-XRT refined analysis
  6. GRB 100915 optical upper limit
  7. GRB 101008: Swift/UVOT Upper Limits
  8. GRB 101008A: Enhanced Swift-XRT position
  9. GRB 101008A: 1.23m CAHA optical observations
  10. GRB 101008A: Swift/XRT Detection of an Afterglow with no UVOT Counterpart
  11. GRB 101008A: Swift detection of a burst
  12. Refined analysis shows Swift Trigger 435520 is not a GRB
  13. Swift Trigger 435520 is probably not a GRB
  14. GRB 100924A: Suzaku WAM observation of the prompt emission
  15. GRB 100928A, Swift-BAT refined analysis
  16. GRB 100924A: Fermi GBM observation
  17. GRB 100928A: Swift detection of a burst
  18. GRB 100925A / MAXI J1659-152: WSRT Radio and Polarization Detection
  19. GRB100925A/MAXI J1659-152: Galactic origin from SED analysis
  20. GRB 100925A / MAXI J1659-152: BOOTES-2/TELMA and IAC80 optical observations
  21. MAXI J1659-152: Swift-BAT refined analysis (triggers 434928 and 434931)
  22. GRB 100925A: Nearby DSS Source - SN-GRB or new Galactic transient?
  23. GRB100925A UVOT afterglow
  24. GRB 100924A: GROND detection of an optical/NIR afterglow
  25. GRB 100925A: Swift detection of a burst
  26. GRB 100924A: Swift-BAT refined analysis
  27. GRB 100924A: Swift detection of a burst
  28. GRB 100917A: TAROT La Silla observatory optical observations
  29. GRB 100915A: TAROT Calern observatory optical observations
  30. GRB100906A: Ashra-1 observation of early optical emission
  31. GRB 100916A: Fermi GBM detection
  32. GRB 100917A: Swift-BAT refined analysis
  33. GRB 100917A: Swift detection of a burst
  34. GRB 100915A: GRT Optical Observation
  35. GRB 100915A: Correction to Swift-BAT refined analysis
  36. GRB 100915A: Swift/UVOT Upper Limits
  37. GRB 100915A: Swift-BAT refined analysis
  38. GRB 100915A: Swift-XRT refined analysis
  39. GRB 100915A: Enhanced Swift-XRT position
  40. GRB 100915A: Swift detection of a likely burst
  41. GRB 100910A: Fermi GBM detection
  42. Swift-BAT trigger 433953 is not a burst
  43. Swift BAT Trigger 433953 probably not a GRB
  44. GRB 100909A: Swift/UVOT observations
  45. GRB 100901A: optical observations in Mondy and R-light curve
  46. GRB 100909A: Swift-XRT refined analysis
  47. GRB 100906A: optical observations at Mt.Terskol
  48. GRB 100901A: optical observation in Maidanak, break confirmation
  49. GRB 100909A: Faulkes Telescope North afterglow candidate
  50. GRB 100909A: ROTSE-III Optical Limits
  51. GRB 100902A : Confirmation of afterglow and re-brightening with CFHT r’-band imaging
  52. GRB 100909A: Swift target of opportunity observation
  53. GRB 100909A: a long GRB detected by INTEGRAL
  54. GRB100906A: detection at 15GHz
  55. EVLA detection of radio afterglow of GRB100901A
  56. GRB 100901A: Confirmation of WSRT Radio Detection
  57. GRB 100901A: CrAO optical observations
  58. GRB100906A: R band observations
  59. Konus-Wind observation of GRB 100906A
  60. GRB100906A: non-detection at 15GHz
  61. GRB 100906A: Fermi GBM observation
  62. GRB 100906A: TLS Monitoring
  63. GRB 100901A: TLS Detection at 5.5 days
  64. GRB 100906A: Swift-XRT refined analysis
  65. GRB 100906A: Enhanced Swift-XRT position
  66. GRB 100906A: Swift/UVOT Observations
  67. GRB 100906A: TLS Multicolor Observations
  68. GRB 100905A: Swift/UVOT Upper Limits
  69. GRB 100901A: ISON-NM optical observations
  70. GRB 100906A: Swift-BAT refined analysis
  71. GRB 100906A: MASTER preliminary polarization prompt light curve
  72. GRB 100906A : Faulkes Telescope North optical observations
  73. GRB 100906A: MASTER early OT observations
  74. GRB 100906A: Swift detection of a burst with an optical afterglow
  75. GRB 100905A: Swift-XRT refined analysis.
  76. GRB 100905A: UKIRT zJHK Observation
  77. GRB 100901A: Possible WSRT Radio Detection
  78. GRB 100905A: Enhanced Swift-XRT position
  79. GRB 100905A: Swift-BAT refined analysis
  80. GRB100904A: BOOTES-3 Upper Limit
  81. GRB 100905A: MASTER Prompt Optical Observations
  82. GRB 100905A: Faulkes Telescope North observations
  83. GRB 100905A: Swift detection of a burst
  84. Optical observations of GRB 100901A
  85. GRB 100902A: UKIRT JK Observation
  86. GRB 100904A: Swift-BAT refined analysis
  87. GRB 100904A: Swift detection of a burst
  88. GRB 100902A: Swift-BAT refined analysis
  89. GRB 100901A: optical observation at Mt.Terskol
  90. GRB 100901A: multicolor photometry at Mt.Terskol
  91. IPN Triangulation of the very bright GRB 100829A
  92. GRB 100901A: Lightbuckets Optical Observations
  93. GRB 100902A: 1.5m OSN I-band Upper Limits
  94. Tentative redshift of GRB100902A from Swift-XRT data
  95. GRB 100902A: Swift XRT refined analysis
  96. GRB 100902A: Swift/UVOT Upper Limits
  97. GRB 100902A: optical observation at Mt.Terskol
  98. GRB 100901A: optical observation at Mt.Terskol
  99. GRB 100902A: Enhanced Swift-XRT position
  100. GRB 100901A: TLS Observations: Break?

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