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

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