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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. GRB080514: REM NIR & Optical Observations
  2. Konus-Wind observation of GRB 080507
  3. GRB 080319B: Further HST observations and underlying host
  4. GRB 080506: NAYUTA Optical Observation
  5. GRB 080507: Suzaku WAM observation of the prompt emission
  6. GRB 080507: Swift XRT analysis confirms the X-ray afterglow
  7. GRB 080507: Keck photometry
  8. GRB 080507: E Pur Si Muove!
  9. GRB 080503: Chandra Observation of X-ray Rebrightening or Flattening
  10. GRB 080503: Hubble Space Telescope Imaging
  11. GRB080507: Swift/UVOT followup observations
  12. GRB 080507: Optical Afterglow
  13. GRB 080506:Optical observations from HCT
  14. GRB 080507: Swift-XRT position of a possible afterglow
  15. GRB 080506: VLA radio upper limit
  16. GRB 080507: GRB localization by SuperAGILE
  17. GRB 080506: TLS 2nd Epoch - possible light curve break
  18. GRB 080503: Fading in continued Gemini imaging
  19. GRB 080506: Swift XRT refined analysis
  20. GRB080506: Swift/UVOT observations
  21. GRB 080506, Swift-BAT refined analysis
  22. GRB080503, RIMOTS optical upper limit
  23. GRB 080506: Observations from NOT
  24. GRB 080506: optical observation from Ondrejov
  25. GRB 080506: TLS afterglow detection in VRIZ
  26. GRB 080506: Enhanced Swift-XRT position
  27. GRB 080506: Optical observation with KANATA/TRISPEC
  28. GRB 080506: Swift detection of a burst with optical afterglow
  29. GRB 080503: VLA radio upper limit
  30. GRB 080503: Observations from NOT
  31. GRB 080503: Slow-rise optical AG ?
  32. GRB 080430: TLS imaging one day after the GRB
  33. GRB 080503: No further optical rebrightening
  34. GRB 080503: Late-time Optical rebrightening (possible mini-SN) - correction
  35. GRB 080503: Late-time Optical rebrightening (possible mini-SN)
  36. GRB 080503, Swift-BAT lag and time-resolved spectral analysis
  37. GRB 080503: MITSuME Ishigakijima optical upper limits
  38. GRB080503: Swift/UVOT Upper Limits
  39. GRB080503 XRT refined analysis
  40. GRB 080503, Swift-BAT refined analysis
  41. GRB 080430
  42. GRB 080430
  43. GRB 080430
  44. GRB 080503: Enhanced Swift-XRT position
  45. GRB 080503: MITSuME Akeno optical upper limits
  46. GRB 080503: New candidate afterglow/host in Gemini imaging
  47. GRB 080503: Optical afterglow candidate and LRIS spectroscopy of the short burst
  48. GRB 080503: Swift detection of a short burst
  49. GRB 080411: Continued Swift Monitoring
  50. GRB 080430: Optical observations
  51. GRB 080430: Shallow decay
  52. GRB080430: RTT150 Optical Observations
  53. GRB080430: Swift/UVOT observations
  54. VLA radio upper limit on GRB 080430
  55. GRB 080430 - multicolor observations of the afterglow
  56. GRB 080430 optical observations
  57. GRB 080430, Swift-BAT refined analysis
  58. GRB080430: optical observations
  59. GRB 080430: Hobby-Eberly Telescope Absorption Redshift
  60. GRB 080430: Swift-XRT refined analysis
  61. GRB 080430: Enhanced Swift-XRT position
  62. GRB080430: Optical observation in AsU CAS Ondrejov & Brno
  63. GRB 080430: Spectroscopy from CAHA
  64. GRB 080430 - SDSS Pre-Burst Observations
  65. GRB 080430: Bootes observation
  66. GRB 080430: Swift detection of a burst with optical afterglow
  67. GRB 080430: TAROT Calern observatory optical observations
  68. GRB960202B - on the association with SN 1996cr
  69. GRB080426: Observations from CAHA
  70. GRB 080426: Swift-XRT refined analysis
  71. GRB080426: Swift/UVOT upper limits
  72. GRB 080426: Enhanced Swift-XRT position
  73. GRB 080426, Swift-BAT refined analysis
  74. GRB 080426: Swift detection of a possibly short burst
  75. Possible GRB 080315: XRT non-detection of afterglow
  76. GRB 080320 : Faulkes Telescope North Observations
  77. GRB 080319A : Liverpool and Faulkes Telescopes Observations
  78. GRB080319A: MAGIC telescope GeV observation
  79. Swift-BAT trigger 309665 is not a GRB
  80. GRB 080420A: ROTSE-III Optical Limits on a possible short burst
  81. GRB 080420?: Swift detection of a possible short burst
  82. GRB080310, BVRcIc field calibration
  83. GRB 080413A: Suzaku/WAM and Swift/BAT joint spectral analysis
  84. GRB 080413B: Rapid PROMPT Observations
  85. Swift XRT and UVOT observations of GRB080414
  86. GRB 080319B: Jet Break, Energetics, Supernova
  87. GRB 080413B: Faulkes Telescope South optical afterglow observations
  88. GRB 080413A: Liverpool Telescope and Faulkes Telescope South optical observations
  89. GRB 080413A: Suzaku WAM observation of the prompt emission
  90. GRB 080413B: Suzaku WAM observation of the prompt emission
  91. GRB 080413A: MOA-II optical afterglow observations
  92. GRB 080319B: Continued Gemini-N monitoring
  93. GRB 080414: RTT150 optical observations
  94. GRB 080414 Watcher observations
  95. GRB 080414: A long GRB detected by INTEGRAL
  96. VLA radio observations of GRB 080413B
  97. GRB 080413A: Gemini-South Spectroscopy
  98. GRB 080413B: Gemini-South Spectroscopy
  99. VLA radio observations of GRB 080413A
  100. IBAS Alert n. 5257 : not a GRB

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