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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 080426: Swift-XRT refined analysis
  2. GRB080426: Swift/UVOT upper limits
  3. GRB 080426: Enhanced Swift-XRT position
  4. GRB 080426, Swift-BAT refined analysis
  5. GRB 080426: Swift detection of a possibly short burst
  6. Possible GRB 080315: XRT non-detection of afterglow
  7. GRB 080320 : Faulkes Telescope North Observations
  8. GRB 080319A : Liverpool and Faulkes Telescopes Observations
  9. GRB080319A: MAGIC telescope GeV observation
  10. Swift-BAT trigger 309665 is not a GRB
  11. GRB 080420A: ROTSE-III Optical Limits on a possible short burst
  12. GRB 080420?: Swift detection of a possible short burst
  13. GRB080310, BVRcIc field calibration
  14. GRB 080413A: Suzaku/WAM and Swift/BAT joint spectral analysis
  15. GRB 080413B: Rapid PROMPT Observations
  16. Swift XRT and UVOT observations of GRB080414
  17. GRB 080319B: Jet Break, Energetics, Supernova
  18. GRB 080413B: Faulkes Telescope South optical afterglow observations
  19. GRB 080413A: Liverpool Telescope and Faulkes Telescope South optical observations
  20. GRB 080413A: Suzaku WAM observation of the prompt emission
  21. GRB 080413B: Suzaku WAM observation of the prompt emission
  22. GRB 080413A: MOA-II optical afterglow observations
  23. GRB 080319B: Continued Gemini-N monitoring
  24. GRB 080414: RTT150 optical observations
  25. GRB 080414 Watcher observations
  26. GRB 080414: A long GRB detected by INTEGRAL
  27. VLA radio observations of GRB 080413B
  28. GRB 080413A: Gemini-South Spectroscopy
  29. GRB 080413B: Gemini-South Spectroscopy
  30. VLA radio observations of GRB 080413A
  31. IBAS Alert n. 5257 : not a GRB
  32. GRB 080413B: Ep,i-Eiso correlation
  33. GRB080413B
  34. Swift-BAT spectral lag analysis of GRB 080413B
  35. GRB 080413a, SMARTS optical/IR afterglow observations
  36. GRB 080413B: Swift XRT refined analysis
  37. GRB080413A: Swift/UVOT observations
  38. GRB 080413B, Swift-BAT refined analysis
  39. GRB 080413A: Swift-XRT refined analysis
  40. GRB 080413A, Swift-BAT refined analysis
  41. GRB 080413A Bootes observation
  42. GRB 080413A: VLT/UVES redshift
  43. GRB 080413B: VLT redshift
  44. GRB080413B: REM NIR & Optical Observation
  45. GRB 080413B: GROND detection of afterglow in all bands
  46. GRB 080413B: Swift detection of a possibly short burst with optical counterpart
  47. GRB 080413A: REM detection of the NIR Afterglow
  48. GRB 080413: Enhanced Swift-XRT position
  49. GRB 080413: TAROT Calern observatory optical observations
  50. GRB 080413: Swift detection of a burst with an optical afterglow
  51. GRB 080413: ROTSE-III Detection of Optical Counterpart
  52. GRB 080411: Swift/UVOT refined analysis
  53. GRB 080411, Swift-BAT refined analysis
  54. GRB 080411: Swift-XRT Refined Analysis
  55. Konus-Wind observation of GRB 080411
  56. GRB 080411: Enhanced Swift-XRT position
  57. GRB 080411: VLT redshift
  58. GRB 080411: GROND detection of optical afterglow candidate
  59. GRB080330: MAGIC telescope GeV observation
  60. GRB 080411: Swift detection of a bright burst
  61. GRB 080330: Swift-XRT refined position retraction
  62. GRB 080409: Swift-BAT refined analysis
  63. GRB 080408: GROND detection of optical/NIR afterglow candidate
  64. GRB 080330 optical observations
  65. Swift/UVOT observations of GRB080409
  66. GRB 080409: Swift XRT refined analysis
  67. UVOT/Swift Observations of GRB080408
  68. GRB 080408: Swift-XRT position of a possible afterglow
  69. GRB 080409: Enhanced Swift-XRT position
  70. GRB 080409: REM optical/NIR observations
  71. GRB 080409: Swift detection of a burst
  72. GRB 080408: Analysis of AGILE Gamma-ray data
  73. GRB 080408: GRB Localization by SuperAGILE
  74. GRB 080319A: Early RAPTOR optical limits
  75. GRB 080319B: HST observations
  76. GRB 080330: RAPTOR detection of prompt optical flash
  77. GRB 080319B: Potential Jet Break Observed by Swift-XRT and UVOT
  78. GRB 080405: Swift-BAT refined analysis
  79. GRB 080405: Swift-XRT position
  80. GRB 080405: Mars Oddysey and Swift-BAT detection, possible host galaxy
  81. GRB 080325: optical upper limit
  82. GRB 080328: GAO 150cm telescope Optical Observation
  83. GRB080330: Improved Swift XRT Position
  84. GRB 080330: Prompt PROMPT Observations
  85. GRB080330: optical observations
  86. GRB 080319B: TORTORA light curve (Correction)
  87. GRB080328, RIMOTS optical upper limit
  88. GRB080330: optical observations
  89. GRB080330: Swift XRT refined analysis
  90. GRB 080330: REM optical observations
  91. GRB 080330, SMARTS optical/IR afterglow observations
  92. GRB 080330 Swift-UVOT refined analysis
  93. GRB 080328: Suzaku WAM observation of the prompt emission
  94. GRB080330: TNT optical observations
  95. GRB 080330, Swift-BAT refined analysis
  96. Konus-Wind observation of GRB 080328
  97. GRB 080330: Redshift Confirmation from Hobby-Eberly Telescope Spectroscopy
  98. GRB080330: LOAO R-band Detection
  99. GRB 080330: GROND Observations
  100. GRB 080330: NOT redshift

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