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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 080514B: slow fading behaviour ?
  2. GRB 080514B: Swift-XRT analysis
  3. GRB 080514B, GROND observations
  4. GRB 080515: Swift detection of a burst
  5. GRB 080514B: Finding chart
  6. GRB 080514B: Afterglow candidate
  7. GRB 080514B: Watcher observations
  8. GRB 080430
  9. GRB 080514B: possible AGILE detection at E>50 MeV
  10. GRB 080514B: SuperAGILE/IPN GRB Localization
  11. procesure for GRB Circular
  12. Swift detection of a possible galactic transient
  13. GRB080514: REM NIR & Optical Observations
  14. Konus-Wind observation of GRB 080507
  15. GRB 080319B: Further HST observations and underlying host
  16. GRB 080506: NAYUTA Optical Observation
  17. GRB 080507: Suzaku WAM observation of the prompt emission
  18. GRB 080507: Swift XRT analysis confirms the X-ray afterglow
  19. GRB 080507: Keck photometry
  20. GRB 080507: E Pur Si Muove!
  21. GRB 080503: Chandra Observation of X-ray Rebrightening or Flattening
  22. GRB 080503: Hubble Space Telescope Imaging
  23. GRB080507: Swift/UVOT followup observations
  24. GRB 080507: Optical Afterglow
  25. GRB 080506:Optical observations from HCT
  26. GRB 080507: Swift-XRT position of a possible afterglow
  27. GRB 080506: VLA radio upper limit
  28. GRB 080507: GRB localization by SuperAGILE
  29. GRB 080506: TLS 2nd Epoch - possible light curve break
  30. GRB 080503: Fading in continued Gemini imaging
  31. GRB 080506: Swift XRT refined analysis
  32. GRB080506: Swift/UVOT observations
  33. GRB 080506, Swift-BAT refined analysis
  34. GRB080503, RIMOTS optical upper limit
  35. GRB 080506: Observations from NOT
  36. GRB 080506: optical observation from Ondrejov
  37. GRB 080506: TLS afterglow detection in VRIZ
  38. GRB 080506: Enhanced Swift-XRT position
  39. GRB 080506: Optical observation with KANATA/TRISPEC
  40. GRB 080506: Swift detection of a burst with optical afterglow
  41. GRB 080503: VLA radio upper limit
  42. GRB 080503: Observations from NOT
  43. GRB 080503: Slow-rise optical AG ?
  44. GRB 080430: TLS imaging one day after the GRB
  45. GRB 080503: No further optical rebrightening
  46. GRB 080503: Late-time Optical rebrightening (possible mini-SN) - correction
  47. GRB 080503: Late-time Optical rebrightening (possible mini-SN)
  48. GRB 080503, Swift-BAT lag and time-resolved spectral analysis
  49. GRB 080503: MITSuME Ishigakijima optical upper limits
  50. GRB080503: Swift/UVOT Upper Limits
  51. GRB080503 XRT refined analysis
  52. GRB 080503, Swift-BAT refined analysis
  53. GRB 080430
  54. GRB 080430
  55. GRB 080430
  56. GRB 080503: Enhanced Swift-XRT position
  57. GRB 080503: MITSuME Akeno optical upper limits
  58. GRB 080503: New candidate afterglow/host in Gemini imaging
  59. GRB 080503: Optical afterglow candidate and LRIS spectroscopy of the short burst
  60. GRB 080503: Swift detection of a short burst
  61. GRB 080411: Continued Swift Monitoring
  62. GRB 080430: Optical observations
  63. GRB 080430: Shallow decay
  64. GRB080430: RTT150 Optical Observations
  65. GRB080430: Swift/UVOT observations
  66. VLA radio upper limit on GRB 080430
  67. GRB 080430 - multicolor observations of the afterglow
  68. GRB 080430 optical observations
  69. GRB 080430, Swift-BAT refined analysis
  70. GRB080430: optical observations
  71. GRB 080430: Hobby-Eberly Telescope Absorption Redshift
  72. GRB 080430: Swift-XRT refined analysis
  73. GRB 080430: Enhanced Swift-XRT position
  74. GRB080430: Optical observation in AsU CAS Ondrejov & Brno
  75. GRB 080430: Spectroscopy from CAHA
  76. GRB 080430 - SDSS Pre-Burst Observations
  77. GRB 080430: Bootes observation
  78. GRB 080430: Swift detection of a burst with optical afterglow
  79. GRB 080430: TAROT Calern observatory optical observations
  80. GRB960202B - on the association with SN 1996cr
  81. GRB080426: Observations from CAHA
  82. GRB 080426: Swift-XRT refined analysis
  83. GRB080426: Swift/UVOT upper limits
  84. GRB 080426: Enhanced Swift-XRT position
  85. GRB 080426, Swift-BAT refined analysis
  86. GRB 080426: Swift detection of a possibly short burst
  87. Possible GRB 080315: XRT non-detection of afterglow
  88. GRB 080320 : Faulkes Telescope North Observations
  89. GRB 080319A : Liverpool and Faulkes Telescopes Observations
  90. GRB080319A: MAGIC telescope GeV observation
  91. Swift-BAT trigger 309665 is not a GRB
  92. GRB 080420A: ROTSE-III Optical Limits on a possible short burst
  93. GRB 080420?: Swift detection of a possible short burst
  94. GRB080310, BVRcIc field calibration
  95. GRB 080413A: Suzaku/WAM and Swift/BAT joint spectral analysis
  96. GRB 080413B: Rapid PROMPT Observations
  97. Swift XRT and UVOT observations of GRB080414
  98. GRB 080319B: Jet Break, Energetics, Supernova
  99. GRB 080413B: Faulkes Telescope South optical afterglow observations
  100. GRB 080413A: Liverpool Telescope and Faulkes Telescope South optical observations

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