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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 080515: Swift-XRT position and analysis
  2. GRB 080520, Swift-BAT refined analysis
  3. GRB 080514B: pseudo-z= 1.8 from prompt emission spectrum
  4. GRB 080514B: UVOT Observations
  5. GRB080520: Swift/UVOT observations
  6. GRB 080520: VLT redshift
  7. GRB 080520, GROND observations
  8. GRB 080520: Enhanced Swift-XRT position
  9. GRB 080520: Swift XRT Refined Analysis
  10. GRB 080520: Swift detection of a burst with optical afterglow
  11. GRB 080514B: Suzaku WAM observation of the prompt emission
  12. Konus-Wind observation of GRB 080514B
  13. GRB 080514B: second epoch Swift XRT data confirms the X-ray afterglow
  14. GRB 080503: Further HST imaging
  15. GRB 080517, Swift-BAT refined analysis
  16. GRB 080516, GROND further analysis
  17. GRB 080517: Swift-XRT refined analysis
  18. GRB 080514B: Further NIR observations
  19. GRB 080517: Enhanced Swift-XRT position
  20. GRB080517: Liverpool Telescope Optical Observations
  21. GRB 080517: Swift detection of a burst
  22. GRB 080516, GROND 2nd epoch observations
  23. GRB 080516, GROND observations
  24. GRB080430: optical observations
  25. GRB 080516, SMARTS optical/IR observations
  26. GRB 080516: Swift-XRT Team refined analysis
  27. GRB 080516, Swift-BAT refined analysis
  28. GRB 080516: Enhanced Swift-XRT position
  29. GRB 080514B: NOT observations
  30. GRB 080516: Swift detection of a burst
  31. Errartum: VLA upper limit on GRB 080507
  32. VLA upper limit on GRB 080705
  33. GRB 080514B : redshift estimation
  34. Konus-Wind observation of GRB 080513
  35. IPN triangulation of bright GRB 080513
  36. Swift-BAT refined analysis for Trigger 311603: Galactic source
  37. GRB 080515, Swift-BAT refined analysis
  38. GRB 080514B: KPNO 4m IR observations
  39. GRB 080514B: slow fading behaviour ?
  40. GRB 080514B: Swift-XRT analysis
  41. GRB 080514B, GROND observations
  42. GRB 080515: Swift detection of a burst
  43. GRB 080514B: Finding chart
  44. GRB 080514B: Afterglow candidate
  45. GRB 080514B: Watcher observations
  46. GRB 080430
  47. GRB 080514B: possible AGILE detection at E>50 MeV
  48. GRB 080514B: SuperAGILE/IPN GRB Localization
  49. procesure for GRB Circular
  50. Swift detection of a possible galactic transient
  51. GRB080514: REM NIR & Optical Observations
  52. Konus-Wind observation of GRB 080507
  53. GRB 080319B: Further HST observations and underlying host
  54. GRB 080506: NAYUTA Optical Observation
  55. GRB 080507: Suzaku WAM observation of the prompt emission
  56. GRB 080507: Swift XRT analysis confirms the X-ray afterglow
  57. GRB 080507: Keck photometry
  58. GRB 080507: E Pur Si Muove!
  59. GRB 080503: Chandra Observation of X-ray Rebrightening or Flattening
  60. GRB 080503: Hubble Space Telescope Imaging
  61. GRB080507: Swift/UVOT followup observations
  62. GRB 080507: Optical Afterglow
  63. GRB 080506:Optical observations from HCT
  64. GRB 080507: Swift-XRT position of a possible afterglow
  65. GRB 080506: VLA radio upper limit
  66. GRB 080507: GRB localization by SuperAGILE
  67. GRB 080506: TLS 2nd Epoch - possible light curve break
  68. GRB 080503: Fading in continued Gemini imaging
  69. GRB 080506: Swift XRT refined analysis
  70. GRB080506: Swift/UVOT observations
  71. GRB 080506, Swift-BAT refined analysis
  72. GRB080503, RIMOTS optical upper limit
  73. GRB 080506: Observations from NOT
  74. GRB 080506: optical observation from Ondrejov
  75. GRB 080506: TLS afterglow detection in VRIZ
  76. GRB 080506: Enhanced Swift-XRT position
  77. GRB 080506: Optical observation with KANATA/TRISPEC
  78. GRB 080506: Swift detection of a burst with optical afterglow
  79. GRB 080503: VLA radio upper limit
  80. GRB 080503: Observations from NOT
  81. GRB 080503: Slow-rise optical AG ?
  82. GRB 080430: TLS imaging one day after the GRB
  83. GRB 080503: No further optical rebrightening
  84. GRB 080503: Late-time Optical rebrightening (possible mini-SN) - correction
  85. GRB 080503: Late-time Optical rebrightening (possible mini-SN)
  86. GRB 080503, Swift-BAT lag and time-resolved spectral analysis
  87. GRB 080503: MITSuME Ishigakijima optical upper limits
  88. GRB080503: Swift/UVOT Upper Limits
  89. GRB080503 XRT refined analysis
  90. GRB 080503, Swift-BAT refined analysis
  91. GRB 080430
  92. GRB 080430
  93. GRB 080430
  94. GRB 080503: Enhanced Swift-XRT position
  95. GRB 080503: MITSuME Akeno optical upper limits
  96. GRB 080503: New candidate afterglow/host in Gemini imaging
  97. GRB 080503: Optical afterglow candidate and LRIS spectroscopy of the short burst
  98. GRB 080503: Swift detection of a short burst
  99. GRB 080411: Continued Swift Monitoring
  100. GRB 080430: Optical observations

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