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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"
  1. GRB 100925A: Swift detection of a burst
  2. GRB 100924A: Swift-BAT refined analysis
  3. GRB 100924A: Swift detection of a burst
  4. GRB 100917A: TAROT La Silla observatory optical observations
  5. GRB 100915A: TAROT Calern observatory optical observations
  6. GRB100906A: Ashra-1 observation of early optical emission
  7. GRB 100916A: Fermi GBM detection
  8. GRB 100917A: Swift-BAT refined analysis
  9. GRB 100917A: Swift detection of a burst
  10. GRB100915A: MITSuME Ishigakijima Optical upper limits
  11. GRB 100915B: GRT Optical Observation
  12. GRB 100915A: GRT Optical Observation
  13. GRB 100915B: Fermi GBM observation
  14. GRB 100915A: Correction to Swift-BAT refined analysis
  15. GRB 100915A: Swift/UVOT Upper Limits
  16. GRB 100915A: Swift-BAT refined analysis
  17. GRB 100915A: Swift-XRT refined analysis
  18. GRB 100915A: Enhanced Swift-XRT position
  19. GRB 100915B: a long GRB detected by INTEGRAL
  20. GRB 100915A: Swift detection of a likely burst
  21. GRB 100910A: Fermi GBM detection
  22. Swift-BAT trigger 433953 is not a burst
  23. Swift BAT Trigger 433953 probably not a GRB
  24. GRB100909A: MITSuME Ishigakijima Optical upper limits
  25. GRB 100909A: Swift/UVOT observations
  26. GRB 100901A: errata of GRB name in GCN 11270
  27. GRB 100901A: optical observations in Mondy and R-light curve
  28. GRB100909A: NOT optical afterglow confirmation
  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 100909A: ROTSE-III Optical Limits
  34. GRB 100909A: Planned XMM-Newton observation
  35. GRB 100902A : Confirmation of afterglow and re-brightening with CFHT r’-band imaging
  36. GRB 100909A: Swift target of opportunity observation
  37. GRB 100909A: a long GRB detected by INTEGRAL
  38. GRB100906A: detection at 15GHz
  39. GRB100901A: IAO optical upper limits at 4 days after the burst
  40. EVLA detection of radio afterglow of GRB100901A
  41. GRB 100901A: Confirmation of WSRT Radio Detection
  42. GRB 100901A: CrAO optical observations
  43. GRB 100906A: RTT150 optical observations
  44. GRB 100906A: GRAS-007 optical observations
  45. GRB100906A: R band observations
  46. Konus-Wind observation of GRB 100906A
  47. GRB100906A: non-detection at 15GHz
  48. GRB100906A: Optical observations at IAO
  49. GRB 100906A: Fermi GBM observation
  50. GRB 100906A: TLS Monitoring
  51. GRB 100901A: TLS Detection at 5.5 days
  52. GRB 100906A: Observations at the Virtual Telescope
  53. GRB 100906A: Swift-XRT refined analysis
  54. GRB 100906A: Enhanced Swift-XRT position
  55. GRB 100906A: Swift/UVOT Observations
  56. GRB100906A: Errata of MITSuME Okayama about observation time
  57. GRB100906A: MITSuME Okayama Optical Observation
  58. GRB 100906A: Ondrejov 65cm observations
  59. GRB 100906A: TLS Multicolor Observations
  60. GRB 100905A: Swift/UVOT Upper Limits
  61. GRB 100901A: TLS observations, SDSS calibration, decay slope
  62. GRB 100906A: MASTER preliminary prompt+afterglow lc
  63. GRB 100901A: ISON-NM optical observations
  64. GRB 100906A: Swift-BAT refined analysis
  65. GRB 100906A: UKIRT zYJHK Observation
  66. GRB 100906A: MASTER preliminary polarization prompt light curve
  67. GRB 100906A: Gemini-N/GMOS redshift
  68. GRB 100906A : Faulkes Telescope North optical observations
  69. GRB 100906A: MASTER early OT observations
  70. GRB 100906A: Swift detection of a burst with an optical afterglow
  71. GRB 100829A: MASTER optical observations
  72. GRB100905A: Optical upper limits at IAO
  73. GRB100905A: MITSuME Okayama optical upper limits
  74. GRB 100905A: Swift-XRT refined analysis.
  75. GRB 100905A: UKIRT zJHK Observation
  76. GRB 100901A: Possible WSRT Radio Detection
  77. GRB100905A: 1.5m OSN upper limit
  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. GRB10901A: Murikabushi telescope observation at 3 days after the burst
  86. GRB 100901A: Submm observations from SMA
  87. GRB 100902A: UKIRT JK Observation
  88. GRB 100902A: GROND observations; afterglow candidate
  89. GRB 100901A: UKIRT zYJHK Observation
  90. GRB 100904A: Swift-BAT refined analysis
  91. GRB100902A: Optical upper limits at IAO
  92. GRB10901A: Optical observations at IAO
  93. Konus-Wind observation of GRB 100829A
  94. GRB 100904A: Swift detection of a burst
  95. GRB 100902A: Swift-BAT refined analysis
  96. GRB 100901A: optical observation at Mt.Terskol
  97. GRB 100901A: multicolor photometry at Mt.Terskol
  98. IPN Triangulation of the very bright GRB 100829A
  99. GRB 100901A: Lightbuckets Optical Observations
  100. GRB 100901A: HCT optical observations

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