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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
  2. GRB 080514B: possible AGILE detection at E>50 MeV
  3. GRB 080514B: SuperAGILE/IPN GRB Localization
  4. procesure for GRB Circular
  5. Swift detection of a possible galactic transient
  6. GRB080514: REM NIR & Optical Observations
  7. Konus-Wind observation of GRB 080507
  8. GRB 080319B: Further HST observations and underlying host
  9. GRB 080506: NAYUTA Optical Observation
  10. GRB 080507: Suzaku WAM observation of the prompt emission
  11. GRB 080507: Swift XRT analysis confirms the X-ray afterglow
  12. GRB 080507: Keck photometry
  13. GRB 080507: E Pur Si Muove!
  14. GRB 080503: Chandra Observation of X-ray Rebrightening or Flattening
  15. GRB 080503: Hubble Space Telescope Imaging
  16. GRB080507: Swift/UVOT followup observations
  17. GRB 080507: Optical Afterglow
  18. GRB 080506:Optical observations from HCT
  19. GRB 080507: Swift-XRT position of a possible afterglow
  20. GRB 080506: VLA radio upper limit
  21. GRB 080507: GRB localization by SuperAGILE
  22. GRB 080506: TLS 2nd Epoch - possible light curve break
  23. GRB 080503: Fading in continued Gemini imaging
  24. GRB 080506: Swift XRT refined analysis
  25. GRB080506: Swift/UVOT observations
  26. GRB 080506, Swift-BAT refined analysis
  27. GRB080503, RIMOTS optical upper limit
  28. GRB 080506: Observations from NOT
  29. GRB 080506: optical observation from Ondrejov
  30. GRB 080506: TLS afterglow detection in VRIZ
  31. GRB 080506: Enhanced Swift-XRT position
  32. GRB 080506: Optical observation with KANATA/TRISPEC
  33. GRB 080506: Swift detection of a burst with optical afterglow
  34. GRB 080503: VLA radio upper limit
  35. GRB 080503: Observations from NOT
  36. GRB 080503: Slow-rise optical AG ?
  37. GRB 080430: TLS imaging one day after the GRB
  38. GRB 080503: No further optical rebrightening
  39. GRB 080503: Late-time Optical rebrightening (possible mini-SN) - correction
  40. GRB 080503: Late-time Optical rebrightening (possible mini-SN)
  41. GRB 080503, Swift-BAT lag and time-resolved spectral analysis
  42. GRB 080503: MITSuME Ishigakijima optical upper limits
  43. GRB080503: Swift/UVOT Upper Limits
  44. GRB080503 XRT refined analysis
  45. GRB 080503, Swift-BAT refined analysis
  46. GRB 080430
  47. GRB 080430
  48. GRB 080430
  49. GRB 080503: Enhanced Swift-XRT position
  50. GRB 080503: MITSuME Akeno optical upper limits
  51. GRB 080503: New candidate afterglow/host in Gemini imaging
  52. GRB 080503: Optical afterglow candidate and LRIS spectroscopy of the short burst
  53. GRB 080503: Swift detection of a short burst
  54. GRB 080411: Continued Swift Monitoring
  55. GRB 080430: Optical observations
  56. GRB 080430: Shallow decay
  57. GRB080430: RTT150 Optical Observations
  58. GRB080430: Swift/UVOT observations
  59. VLA radio upper limit on GRB 080430
  60. GRB 080430 - multicolor observations of the afterglow
  61. GRB 080430 optical observations
  62. GRB 080430, Swift-BAT refined analysis
  63. GRB080430: optical observations
  64. GRB 080430: Hobby-Eberly Telescope Absorption Redshift
  65. GRB 080430: Swift-XRT refined analysis
  66. GRB 080430: Enhanced Swift-XRT position
  67. GRB080430: Optical observation in AsU CAS Ondrejov & Brno
  68. GRB 080430: Spectroscopy from CAHA
  69. GRB 080430 - SDSS Pre-Burst Observations
  70. GRB 080430: Bootes observation
  71. GRB 080430: Swift detection of a burst with optical afterglow
  72. GRB 080430: TAROT Calern observatory optical observations
  73. GRB960202B - on the association with SN 1996cr
  74. GRB080426: Observations from CAHA
  75. GRB 080426: Swift-XRT refined analysis
  76. GRB080426: Swift/UVOT upper limits
  77. GRB 080426: Enhanced Swift-XRT position
  78. GRB 080426, Swift-BAT refined analysis
  79. GRB 080426: Swift detection of a possibly short burst
  80. Possible GRB 080315: XRT non-detection of afterglow
  81. GRB 080320 : Faulkes Telescope North Observations
  82. GRB 080319A : Liverpool and Faulkes Telescopes Observations
  83. GRB080319A: MAGIC telescope GeV observation
  84. Swift-BAT trigger 309665 is not a GRB
  85. GRB 080420A: ROTSE-III Optical Limits on a possible short burst
  86. GRB 080420?: Swift detection of a possible short burst
  87. GRB080310, BVRcIc field calibration
  88. GRB 080413A: Suzaku/WAM and Swift/BAT joint spectral analysis
  89. GRB 080413B: Rapid PROMPT Observations
  90. Swift XRT and UVOT observations of GRB080414
  91. GRB 080319B: Jet Break, Energetics, Supernova
  92. GRB 080413B: Faulkes Telescope South optical afterglow observations
  93. GRB 080413A: Liverpool Telescope and Faulkes Telescope South optical observations
  94. GRB 080413A: Suzaku WAM observation of the prompt emission
  95. GRB 080413B: Suzaku WAM observation of the prompt emission
  96. GRB 080413A: MOA-II optical afterglow observations
  97. GRB 080319B: Continued Gemini-N monitoring
  98. GRB 080414: RTT150 optical observations
  99. GRB 080414 Watcher observations
  100. GRB 080414: A long GRB detected by INTEGRAL

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