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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"

36801 results found.

  1. GRB 060421: Swift-BAT Refined Analysis
  2. GRB 060421: Swift-XRT refined analysis
  3. GRB 060418: prediction of t_break
  4. GRB060418: optical observations
  5. Konus-Wind observation of GRB 060418
  6. GRB(?)060421:MASTER optical limit
  7. GRB(?)060421 : XRT position
  8. GRB(?) 060421: Swift detection of a burst
  9. Erratum of GCN 4983 for GRB 060418 IR follow-up
  10. GRB 060418 : IR afterglow observations
  11. GRB 060418 : Lulin Optical follow-up
  12. GRB 060418: JHKs PAIRITEL Observations of Afterglow
  13. GRB 060418: Radio Observations
  14. GRB060418, BVRcIc field calibration
  15. GRB060418: Optical Observations
  16. GRB 060418: FRAM early afterglow observation
  17. GRB 060418: Refined Analysis of the Swift-BAT burst
  18. GRB060418: Swift XRT Team Refined Analysis
  19. GRB 060418, SMARTS continuing afterglow observations
  20. GRB 060418: PROMPT Detections
  21. GRB 060418, SMARTS optical/IR afterglow observations
  22. GRB060418: Magellan/MIKE Spectroscopic Redshift
  23. GRB060418 : LT optical afterglow observation
  24. GRB 060418: REM candidate afterglow
  25. GRB 060418: Swift detection of a burst with bright x-ray and optical afterglow
  26. GRB 060413: REM NIR Observations
  27. GRB 060413: Refined analysis of the Swift-BAT burst
  28. GRB 060413: Watcher UBVR observations
  29. GRB 060413: XRT refined analysis
  30. GRB 060413: No Optical Afterglow in Swift/UVOT TDRSS Data
  31. GRB 060413: Swift detection of a burst
  32. GRB060403: optical observations
  33. GRB 060403 Optical observations
  34. GRB 060403: MITSuME optical observation
  35. GRB060403: XRT refined analysis
  36. GRB 060403: Swift/UVOT upper limits
  37. GRB 060403: Refined analysis of the Swift-BAT burst
  38. GRB 060403: Swift detection of a burst
  39. GRB 060322: LNA optical limit
  40. GRB 060218SN 2006aj: optical observations at Rozhen Observatory
  41. GRB 060323 : WIDGET simultaneous optical observations
  42. GRB 060323: Early optical observation at Xinglong
  43. GRB060218, optical observations
  44. GRB 060322: Confirmation of Swift XRT afterglow
  45. GRB 060211A: optical observation
  46. GRB060323: optical limit
  47. GRB060211B: optical observation
  48. GRB060323: NOT optical observations
  49. GRB 060322: IAC80 optical observations
  50. GRB 060322: Swift XRT afterglow candidate
  51. GRB 060323: Swift/UVOT Observations
  52. GRB 060323: optical afterglow confirmed
  53. GRB060323: NOT observations
  54. GRB 060323: Optical Observations
  55. GRB 060323: Tautenburg OT candidate retraction
  56. GRB 060323: Refined analysis of the Swift-BAT burst
  57. GRB 060323: optical observations at TNG
  58. GRB 060323: Swift XRT refined analysis
  59. GRB 060323: BVRI observations at Tautenburg, aftreglow candidate
  60. GRB 060323: Swift/XRT position
  61. GRB 060322: Refined analysis of the Swift-BAT burst
  62. GRB060323 - SDSS Pre-Burst Observations
  63. GRB 060323: Swift detection of a burst with a possible optical afterglow
  64. GRB 060322: Swift-BAT detection of a 200-sec burst
  65. GRB060219: optical observation
  66. GRB060206: optical observation
  67. GRB060218/SN2006aj: optical observations
  68. GRB 060218/SN 2006aj, LNA optical observation
  69. GRB060218: Refined photometric calibration of comparison stars
  70. GRB 060319: WHT K-band candidate afterglow
  71. GRB 060319: IAC-80 optical observations
  72. GRB060319: Swift XRT refined analysis
  73. GRB 060319: Re-analysis of TNG data
  74. GRB060319: MASTER limit
  75. GRB 060319: Swift-BAT refined analysis
  76. GRB 060319 optical observations at TNG
  77. GRB060319 : Liverpool Telescope optical limit
  78. GRB060319: MASTER optical observation
  79. GRB060319 - SDSS Pre-burst Observations
  80. GRB 060319: Swift detection of a burst
  81. GRB060313: Radio Observations
  82. GRB 060313: early afterglow NIR upper limits with REM
  83. IBAS Alert n. 3221: not a GRB
  84. Konus-Wind observation of GRB 060313
  85. GRB060313: SSO 40inch Observations
  86. GRB 060313: Further analysis of the Swift-BAT bright short hard burst
  87. GRB 060313: PROMPT Observations
  88. GRB 060313: Swift/UVOT Observations
  89. GRB060313:Gemini South Observations
  90. GRB 060313: Swift-XRT team refined analysis
  91. GRB060313: optical observations of the afterglow candidate
  92. GRB 060313: Refined analysis of the Swift-BAT bright short hard burst
  93. GRB 060313, SMARTS optical counterpart?
  94. GRB 060313: Possible optical counterpart
  95. GRB 060313: Swift XRT position
  96. GRB 060313, SMARTS optical/IR observations
  97. GRB060313: optical and near infrared observations with REM
  98. GRB 060313: Swift-BAT detection of a bright short hard burst
  99. GRB060218: SARA Observations of SN2006aj
  100. GRB 060312: Refined analysis of the Swift-BAT burst

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