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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 080503: Late-time Optical rebrightening (possible mini-SN)
  2. GRB 080503, Swift-BAT lag and time-resolved spectral analysis
  3. GRB 080503: MITSuME Ishigakijima optical upper limits
  4. GRB080503: Swift/UVOT Upper Limits
  5. GRB080503 XRT refined analysis
  6. GRB 080503, Swift-BAT refined analysis
  7. GRB 080430
  8. GRB 080430
  9. GRB 080430
  10. GRB 080503: Enhanced Swift-XRT position
  11. GRB 080503: MITSuME Akeno optical upper limits
  12. GRB 080503: New candidate afterglow/host in Gemini imaging
  13. GRB 080503: Optical afterglow candidate and LRIS spectroscopy of the short burst
  14. GRB 080503: Swift detection of a short burst
  15. GRB 080411: Continued Swift Monitoring
  16. GRB 080430: Optical observations
  17. GRB 080430: Shallow decay
  18. GRB080430: RTT150 Optical Observations
  19. GRB080430: Swift/UVOT observations
  20. VLA radio upper limit on GRB 080430
  21. GRB 080430 - multicolor observations of the afterglow
  22. GRB 080430 optical observations
  23. GRB 080430, Swift-BAT refined analysis
  24. GRB080430: optical observations
  25. GRB 080430: Hobby-Eberly Telescope Absorption Redshift
  26. GRB 080430: Swift-XRT refined analysis
  27. GRB 080430: Enhanced Swift-XRT position
  28. GRB080430: Optical observation in AsU CAS Ondrejov & Brno
  29. GRB 080430: Spectroscopy from CAHA
  30. GRB 080430 - SDSS Pre-Burst Observations
  31. GRB 080430: Bootes observation
  32. GRB 080430: Swift detection of a burst with optical afterglow
  33. GRB 080430: TAROT Calern observatory optical observations
  34. GRB960202B - on the association with SN 1996cr
  35. GRB080426: Observations from CAHA
  36. GRB 080426: Swift-XRT refined analysis
  37. GRB080426: Swift/UVOT upper limits
  38. GRB 080426: Enhanced Swift-XRT position
  39. GRB 080426, Swift-BAT refined analysis
  40. GRB 080426: Swift detection of a possibly short burst
  41. Possible GRB 080315: XRT non-detection of afterglow
  42. GRB 080320 : Faulkes Telescope North Observations
  43. GRB 080319A : Liverpool and Faulkes Telescopes Observations
  44. GRB080319A: MAGIC telescope GeV observation
  45. Swift-BAT trigger 309665 is not a GRB
  46. GRB 080420A: ROTSE-III Optical Limits on a possible short burst
  47. GRB 080420?: Swift detection of a possible short burst
  48. GRB080310, BVRcIc field calibration
  49. GRB 080413A: Suzaku/WAM and Swift/BAT joint spectral analysis
  50. GRB 080413B: Rapid PROMPT Observations
  51. Swift XRT and UVOT observations of GRB080414
  52. GRB 080319B: Jet Break, Energetics, Supernova
  53. GRB 080413B: Faulkes Telescope South optical afterglow observations
  54. GRB 080413A: Liverpool Telescope and Faulkes Telescope South optical observations
  55. GRB 080413A: Suzaku WAM observation of the prompt emission
  56. GRB 080413B: Suzaku WAM observation of the prompt emission
  57. GRB 080413A: MOA-II optical afterglow observations
  58. GRB 080319B: Continued Gemini-N monitoring
  59. GRB 080414: RTT150 optical observations
  60. GRB 080414 Watcher observations
  61. GRB 080414: A long GRB detected by INTEGRAL
  62. VLA radio observations of GRB 080413B
  63. GRB 080413A: Gemini-South Spectroscopy
  64. GRB 080413B: Gemini-South Spectroscopy
  65. VLA radio observations of GRB 080413A
  66. IBAS Alert n. 5257 : not a GRB
  67. GRB 080413B: Ep,i-Eiso correlation
  68. GRB080413B
  69. Swift-BAT spectral lag analysis of GRB 080413B
  70. GRB 080413a, SMARTS optical/IR afterglow observations
  71. GRB 080413B: Swift XRT refined analysis
  72. GRB080413A: Swift/UVOT observations
  73. GRB 080413B, Swift-BAT refined analysis
  74. GRB 080413A: Swift-XRT refined analysis
  75. GRB 080413A, Swift-BAT refined analysis
  76. GRB 080413A Bootes observation
  77. GRB 080413A: VLT/UVES redshift
  78. GRB 080413B: VLT redshift
  79. GRB080413B: REM NIR & Optical Observation
  80. GRB 080413B: GROND detection of afterglow in all bands
  81. GRB 080413B: Swift detection of a possibly short burst with optical counterpart
  82. GRB 080413A: REM detection of the NIR Afterglow
  83. GRB 080413: Enhanced Swift-XRT position
  84. GRB 080413: TAROT Calern observatory optical observations
  85. GRB 080413: Swift detection of a burst with an optical afterglow
  86. GRB 080413: ROTSE-III Detection of Optical Counterpart
  87. GRB 080411: Swift/UVOT refined analysis
  88. GRB 080411, Swift-BAT refined analysis
  89. GRB 080411: Swift-XRT Refined Analysis
  90. Konus-Wind observation of GRB 080411
  91. GRB 080411: Enhanced Swift-XRT position
  92. GRB 080411: VLT redshift
  93. GRB 080411: GROND detection of optical afterglow candidate
  94. GRB080330: MAGIC telescope GeV observation
  95. GRB 080411: Swift detection of a bright burst
  96. GRB 080330: Swift-XRT refined position retraction
  97. GRB 080409: Swift-BAT refined analysis
  98. GRB 080408: GROND detection of optical/NIR afterglow candidate
  99. GRB 080330 optical observations
  100. Swift/UVOT observations of GRB080409

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