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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 080430: TLS imaging one day after the GRB
  2. GRB 080503: No further optical rebrightening
  3. GRB 080503: Late-time Optical rebrightening (possible mini-SN) - correction
  4. GRB 080503: Late-time Optical rebrightening (possible mini-SN)
  5. GRB 080503, Swift-BAT lag and time-resolved spectral analysis
  6. GRB 080503: MITSuME Ishigakijima optical upper limits
  7. GRB080503: Swift/UVOT Upper Limits
  8. GRB080503 XRT refined analysis
  9. GRB 080503, Swift-BAT refined analysis
  10. GRB 080430
  11. GRB 080430
  12. GRB 080430
  13. GRB 080503: Enhanced Swift-XRT position
  14. GRB 080503: MITSuME Akeno optical upper limits
  15. GRB 080503: New candidate afterglow/host in Gemini imaging
  16. GRB 080503: Optical afterglow candidate and LRIS spectroscopy of the short burst
  17. GRB 080503: Swift detection of a short burst
  18. GRB 080411: Continued Swift Monitoring
  19. GRB 080430: Optical observations
  20. GRB 080430: Shallow decay
  21. GRB080430: RTT150 Optical Observations
  22. GRB080430: Swift/UVOT observations
  23. VLA radio upper limit on GRB 080430
  24. GRB 080430 - multicolor observations of the afterglow
  25. GRB 080430 optical observations
  26. GRB 080430, Swift-BAT refined analysis
  27. GRB080430: optical observations
  28. GRB 080430: Hobby-Eberly Telescope Absorption Redshift
  29. GRB 080430: Swift-XRT refined analysis
  30. GRB 080430: Enhanced Swift-XRT position
  31. GRB080430: Optical observation in AsU CAS Ondrejov & Brno
  32. GRB 080430: Spectroscopy from CAHA
  33. GRB 080430 - SDSS Pre-Burst Observations
  34. GRB 080430: Bootes observation
  35. GRB 080430: Swift detection of a burst with optical afterglow
  36. GRB 080430: TAROT Calern observatory optical observations
  37. GRB960202B - on the association with SN 1996cr
  38. GRB080426: Observations from CAHA
  39. GRB 080426: Swift-XRT refined analysis
  40. GRB080426: Swift/UVOT upper limits
  41. GRB 080426: Enhanced Swift-XRT position
  42. GRB 080426, Swift-BAT refined analysis
  43. GRB 080426: Swift detection of a possibly short burst
  44. Possible GRB 080315: XRT non-detection of afterglow
  45. GRB 080320 : Faulkes Telescope North Observations
  46. GRB 080319A : Liverpool and Faulkes Telescopes Observations
  47. GRB080319A: MAGIC telescope GeV observation
  48. Swift-BAT trigger 309665 is not a GRB
  49. GRB 080420A: ROTSE-III Optical Limits on a possible short burst
  50. GRB 080420?: Swift detection of a possible short burst
  51. GRB080310, BVRcIc field calibration
  52. GRB 080413A: Suzaku/WAM and Swift/BAT joint spectral analysis
  53. GRB 080413B: Rapid PROMPT Observations
  54. Swift XRT and UVOT observations of GRB080414
  55. GRB 080319B: Jet Break, Energetics, Supernova
  56. GRB 080413B: Faulkes Telescope South optical afterglow observations
  57. GRB 080413A: Liverpool Telescope and Faulkes Telescope South optical observations
  58. GRB 080413A: Suzaku WAM observation of the prompt emission
  59. GRB 080413B: Suzaku WAM observation of the prompt emission
  60. GRB 080413A: MOA-II optical afterglow observations
  61. GRB 080319B: Continued Gemini-N monitoring
  62. GRB 080414: RTT150 optical observations
  63. GRB 080414 Watcher observations
  64. GRB 080414: A long GRB detected by INTEGRAL
  65. VLA radio observations of GRB 080413B
  66. GRB 080413A: Gemini-South Spectroscopy
  67. GRB 080413B: Gemini-South Spectroscopy
  68. VLA radio observations of GRB 080413A
  69. IBAS Alert n. 5257 : not a GRB
  70. GRB 080413B: Ep,i-Eiso correlation
  71. GRB080413B
  72. Swift-BAT spectral lag analysis of GRB 080413B
  73. GRB 080413a, SMARTS optical/IR afterglow observations
  74. GRB 080413B: Swift XRT refined analysis
  75. GRB080413A: Swift/UVOT observations
  76. GRB 080413B, Swift-BAT refined analysis
  77. GRB 080413A: Swift-XRT refined analysis
  78. GRB 080413A, Swift-BAT refined analysis
  79. GRB 080413A Bootes observation
  80. GRB 080413A: VLT/UVES redshift
  81. GRB 080413B: VLT redshift
  82. GRB080413B: REM NIR & Optical Observation
  83. GRB 080413B: GROND detection of afterglow in all bands
  84. GRB 080413B: Swift detection of a possibly short burst with optical counterpart
  85. GRB 080413A: REM detection of the NIR Afterglow
  86. GRB 080413: Enhanced Swift-XRT position
  87. GRB 080413: TAROT Calern observatory optical observations
  88. GRB 080413: Swift detection of a burst with an optical afterglow
  89. GRB 080413: ROTSE-III Detection of Optical Counterpart
  90. GRB 080411: Swift/UVOT refined analysis
  91. GRB 080411, Swift-BAT refined analysis
  92. GRB 080411: Swift-XRT Refined Analysis
  93. Konus-Wind observation of GRB 080411
  94. GRB 080411: Enhanced Swift-XRT position
  95. GRB 080411: VLT redshift
  96. GRB 080411: GROND detection of optical afterglow candidate
  97. GRB080330: MAGIC telescope GeV observation
  98. GRB 080411: Swift detection of a bright burst
  99. GRB 080330: Swift-XRT refined position retraction
  100. GRB 080409: Swift-BAT refined analysis

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