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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"

27774 results found.

  1. GRB 101011A: XRT Refined Analysis
  2. GRB 101011A: Swift/UVOT Observations of a Possible Optical Afterglow
  3. GRB 101011A: Enhanced Swift-XRT position
  4. GRB 101011A: Swift-BAT refined analysis
  5. GRB 101011A: Swift detection of a burst
  6. GRB 101008A: Fermi GBM observation
  7. GRB 101008A: MASTER prompt optical observations
  8. GRB 101008A: Swift-BAT refined analysis
  9. GRB101008A, GROND detection of a fading afterglow
  10. GRB 101008A: Swift-XRT refined analysis
  11. GRB 100915 optical upper limit
  12. GRB 101008: Swift/UVOT Upper Limits
  13. GRB 101008A: Enhanced Swift-XRT position
  14. GRB 101008A: 1.23m CAHA optical observations
  15. GRB 101008A: Swift/XRT Detection of an Afterglow with no UVOT Counterpart
  16. GRB 101008A: Swift detection of a burst
  17. Refined analysis shows Swift Trigger 435520 is not a GRB
  18. Swift Trigger 435520 is probably not a GRB
  19. GRB 100924A: Suzaku WAM observation of the prompt emission
  20. GRB 100928A, Swift-BAT refined analysis
  21. GRB 100924A: Fermi GBM observation
  22. GRB 100928A: Swift detection of a burst
  23. GRB 100925A / MAXI J1659-152: WSRT Radio and Polarization Detection
  24. GRB100925A/MAXI J1659-152: Galactic origin from SED analysis
  25. GRB 100925A / MAXI J1659-152: BOOTES-2/TELMA and IAC80 optical observations
  26. MAXI J1659-152: Swift-BAT refined analysis (triggers 434928 and 434931)
  27. GRB 100925A: Nearby DSS Source - SN-GRB or new Galactic transient?
  28. GRB100925A UVOT afterglow
  29. GRB 100924A: GROND detection of an optical/NIR afterglow
  30. GRB 100925A: Swift detection of a burst
  31. GRB 100924A: Swift-BAT refined analysis
  32. GRB 100924A: Swift detection of a burst
  33. GRB 100917A: TAROT La Silla observatory optical observations
  34. GRB 100915A: TAROT Calern observatory optical observations
  35. GRB100906A: Ashra-1 observation of early optical emission
  36. GRB 100916A: Fermi GBM detection
  37. GRB 100917A: Swift-BAT refined analysis
  38. GRB 100917A: Swift detection of a burst
  39. GRB 100915A: GRT Optical Observation
  40. GRB 100915A: Correction to Swift-BAT refined analysis
  41. GRB 100915A: Swift/UVOT Upper Limits
  42. GRB 100915A: Swift-BAT refined analysis
  43. GRB 100915A: Swift-XRT refined analysis
  44. GRB 100915A: Enhanced Swift-XRT position
  45. GRB 100915A: Swift detection of a likely burst
  46. GRB 100910A: Fermi GBM detection
  47. Swift-BAT trigger 433953 is not a burst
  48. Swift BAT Trigger 433953 probably not a GRB
  49. GRB 100909A: Swift/UVOT observations
  50. GRB 100901A: optical observations in Mondy and R-light curve
  51. GRB 100909A: Swift-XRT refined analysis
  52. GRB 100906A: optical observations at Mt.Terskol
  53. GRB 100901A: optical observation in Maidanak, break confirmation
  54. GRB 100909A: Faulkes Telescope North afterglow candidate
  55. GRB 100909A: ROTSE-III Optical Limits
  56. GRB 100902A : Confirmation of afterglow and re-brightening with CFHT r’-band imaging
  57. GRB 100909A: Swift target of opportunity observation
  58. GRB 100909A: a long GRB detected by INTEGRAL
  59. GRB100906A: detection at 15GHz
  60. EVLA detection of radio afterglow of GRB100901A
  61. GRB 100901A: Confirmation of WSRT Radio Detection
  62. GRB 100901A: CrAO optical observations
  63. GRB100906A: R band observations
  64. Konus-Wind observation of GRB 100906A
  65. GRB100906A: non-detection at 15GHz
  66. GRB 100906A: Fermi GBM observation
  67. GRB 100906A: TLS Monitoring
  68. GRB 100901A: TLS Detection at 5.5 days
  69. GRB 100906A: Swift-XRT refined analysis
  70. GRB 100906A: Enhanced Swift-XRT position
  71. GRB 100906A: Swift/UVOT Observations
  72. GRB 100906A: TLS Multicolor Observations
  73. GRB 100905A: Swift/UVOT Upper Limits
  74. GRB 100901A: ISON-NM optical observations
  75. GRB 100906A: Swift-BAT refined analysis
  76. GRB 100906A: MASTER preliminary polarization prompt light curve
  77. GRB 100906A : Faulkes Telescope North optical observations
  78. GRB 100906A: MASTER early OT observations
  79. GRB 100906A: Swift detection of a burst with an optical afterglow
  80. GRB 100905A: Swift-XRT refined analysis.
  81. GRB 100905A: UKIRT zJHK Observation
  82. GRB 100901A: Possible WSRT Radio Detection
  83. GRB 100905A: Enhanced Swift-XRT position
  84. GRB 100905A: Swift-BAT refined analysis
  85. GRB100904A: BOOTES-3 Upper Limit
  86. GRB 100905A: MASTER Prompt Optical Observations
  87. GRB 100905A: Faulkes Telescope North observations
  88. GRB 100905A: Swift detection of a burst
  89. Optical observations of GRB 100901A
  90. GRB 100902A: UKIRT JK Observation
  91. GRB 100904A: Swift-BAT refined analysis
  92. GRB 100904A: Swift detection of a burst
  93. GRB 100902A: Swift-BAT refined analysis
  94. GRB 100901A: optical observation at Mt.Terskol
  95. GRB 100901A: multicolor photometry at Mt.Terskol
  96. IPN Triangulation of the very bright GRB 100829A
  97. GRB 100901A: Lightbuckets Optical Observations
  98. GRB 100902A: 1.5m OSN I-band Upper Limits
  99. Tentative redshift of GRB100902A from Swift-XRT data
  100. GRB 100902A: Swift XRT refined analysis

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