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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 080516: Swift-XRT Team refined analysis
  2. GRB 080516, Swift-BAT refined analysis
  3. GRB 080516: Enhanced Swift-XRT position
  4. GRB 080514B: NOT observations
  5. GRB 080516: Swift detection of a burst
  6. Errartum: VLA upper limit on GRB 080507
  7. VLA upper limit on GRB 080705
  8. GRB 080514B : redshift estimation
  9. Konus-Wind observation of GRB 080513
  10. IPN triangulation of bright GRB 080513
  11. Swift-BAT refined analysis for Trigger 311603: Galactic source
  12. GRB 080515, Swift-BAT refined analysis
  13. GRB 080514B: KPNO 4m IR observations
  14. GRB 080514B: slow fading behaviour ?
  15. GRB 080514B: Swift-XRT analysis
  16. GRB 080514B, GROND observations
  17. GRB 080515: Swift detection of a burst
  18. GRB 080514B: Finding chart
  19. GRB 080514B: Afterglow candidate
  20. GRB 080514B: Watcher observations
  21. GRB 080430
  22. GRB 080514B: possible AGILE detection at E>50 MeV
  23. GRB 080514B: SuperAGILE/IPN GRB Localization
  24. procesure for GRB Circular
  25. Swift detection of a possible galactic transient
  26. GRB080514: REM NIR & Optical Observations
  27. Konus-Wind observation of GRB 080507
  28. GRB 080319B: Further HST observations and underlying host
  29. GRB 080506: NAYUTA Optical Observation
  30. GRB 080507: Suzaku WAM observation of the prompt emission
  31. GRB 080507: Swift XRT analysis confirms the X-ray afterglow
  32. GRB 080507: Keck photometry
  33. GRB 080507: E Pur Si Muove!
  34. GRB 080503: Chandra Observation of X-ray Rebrightening or Flattening
  35. GRB 080503: Hubble Space Telescope Imaging
  36. GRB080507: Swift/UVOT followup observations
  37. GRB 080507: Optical Afterglow
  38. GRB 080506:Optical observations from HCT
  39. GRB 080507: Swift-XRT position of a possible afterglow
  40. GRB 080506: VLA radio upper limit
  41. GRB 080507: GRB localization by SuperAGILE
  42. GRB 080506: TLS 2nd Epoch - possible light curve break
  43. GRB 080503: Fading in continued Gemini imaging
  44. GRB 080506: Swift XRT refined analysis
  45. GRB080506: Swift/UVOT observations
  46. GRB 080506, Swift-BAT refined analysis
  47. GRB080503, RIMOTS optical upper limit
  48. GRB 080506: Observations from NOT
  49. GRB 080506: optical observation from Ondrejov
  50. GRB 080506: TLS afterglow detection in VRIZ
  51. GRB 080506: Enhanced Swift-XRT position
  52. GRB 080506: Optical observation with KANATA/TRISPEC
  53. GRB 080506: Swift detection of a burst with optical afterglow
  54. GRB 080503: VLA radio upper limit
  55. GRB 080503: Observations from NOT
  56. GRB 080503: Slow-rise optical AG ?
  57. GRB 080430: TLS imaging one day after the GRB
  58. GRB 080503: No further optical rebrightening
  59. GRB 080503: Late-time Optical rebrightening (possible mini-SN) - correction
  60. GRB 080503: Late-time Optical rebrightening (possible mini-SN)
  61. GRB 080503, Swift-BAT lag and time-resolved spectral analysis
  62. GRB 080503: MITSuME Ishigakijima optical upper limits
  63. GRB080503: Swift/UVOT Upper Limits
  64. GRB080503 XRT refined analysis
  65. GRB 080503, Swift-BAT refined analysis
  66. GRB 080430
  67. GRB 080430
  68. GRB 080430
  69. GRB 080503: Enhanced Swift-XRT position
  70. GRB 080503: MITSuME Akeno optical upper limits
  71. GRB 080503: New candidate afterglow/host in Gemini imaging
  72. GRB 080503: Optical afterglow candidate and LRIS spectroscopy of the short burst
  73. GRB 080503: Swift detection of a short burst
  74. GRB 080411: Continued Swift Monitoring
  75. GRB 080430: Optical observations
  76. GRB 080430: Shallow decay
  77. GRB080430: RTT150 Optical Observations
  78. GRB080430: Swift/UVOT observations
  79. VLA radio upper limit on GRB 080430
  80. GRB 080430 - multicolor observations of the afterglow
  81. GRB 080430 optical observations
  82. GRB 080430, Swift-BAT refined analysis
  83. GRB080430: optical observations
  84. GRB 080430: Hobby-Eberly Telescope Absorption Redshift
  85. GRB 080430: Swift-XRT refined analysis
  86. GRB 080430: Enhanced Swift-XRT position
  87. GRB080430: Optical observation in AsU CAS Ondrejov & Brno
  88. GRB 080430: Spectroscopy from CAHA
  89. GRB 080430 - SDSS Pre-Burst Observations
  90. GRB 080430: Bootes observation
  91. GRB 080430: Swift detection of a burst with optical afterglow
  92. GRB 080430: TAROT Calern observatory optical observations
  93. GRB960202B - on the association with SN 1996cr
  94. GRB080426: Observations from CAHA
  95. GRB 080426: Swift-XRT refined analysis
  96. GRB080426: Swift/UVOT upper limits
  97. GRB 080426: Enhanced Swift-XRT position
  98. GRB 080426, Swift-BAT refined analysis
  99. GRB 080426: Swift detection of a possibly short burst
  100. Possible GRB 080315: XRT non-detection of afterglow

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