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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"

35422 results found.

  1. GRB 060428: Swift detection of a burst
  2. GRB 060427: NOT observations
  3. GRB 060427: Swift/UVOT upper limits.
  4. GRB 060427: Refined analysis of the Swift-BAT burst
  5. GRB060418: Swift XRT Team Further Refined Analysis
  6. GRB060425:MASTER survey observations
  7. GRB 060427, optical observation
  8. GRB 060427: Swift detection of a burst
  9. GRB 060425: IPN localization and KW spectrum of a short, hard burst
  10. An interactive program for GRB pseudo-redshift computations
  11. GRB060424: optical afterglow detection
  12. GRB060418: Further Analysis of MIKE Spectroscopy
  13. GRB 060424: Refined analysis of the Swift-BAT burst
  14. GRB 060424: Swift detection of a burst
  15. GRB 060421: TTT Observations
  16. GRB 060421: Swift-BAT Refined Analysis
  17. GRB 060421: Swift-XRT refined analysis
  18. GRB 060418: prediction of t_break
  19. GRB060418: optical observations
  20. Konus-Wind observation of GRB 060418
  21. GRB(?)060421:MASTER optical limit
  22. GRB(?)060421 : XRT position
  23. GRB(?) 060421: Swift detection of a burst
  24. Erratum of GCN 4983 for GRB 060418 IR follow-up
  25. GRB 060418 : IR afterglow observations
  26. GRB 060418 : Lulin Optical follow-up
  27. GRB 060418: JHKs PAIRITEL Observations of Afterglow
  28. GRB 060418: Radio Observations
  29. GRB060418, BVRcIc field calibration
  30. GRB060418: Optical Observations
  31. GRB 060418: FRAM early afterglow observation
  32. GRB 060418: Refined Analysis of the Swift-BAT burst
  33. GRB060418: Swift XRT Team Refined Analysis
  34. GRB 060418, SMARTS continuing afterglow observations
  35. GRB 060418: PROMPT Detections
  36. GRB 060418, SMARTS optical/IR afterglow observations
  37. GRB060418: Magellan/MIKE Spectroscopic Redshift
  38. GRB060418 : LT optical afterglow observation
  39. GRB 060418: REM candidate afterglow
  40. GRB 060418: Swift detection of a burst with bright x-ray and optical afterglow
  41. GRB 060413: REM NIR Observations
  42. GRB 060413: Refined analysis of the Swift-BAT burst
  43. GRB 060413: Watcher UBVR observations
  44. GRB 060413: XRT refined analysis
  45. GRB 060413: No Optical Afterglow in Swift/UVOT TDRSS Data
  46. GRB 060413: Swift detection of a burst
  47. GRB060403: optical observations
  48. GRB 060403 Optical observations
  49. GRB 060403: MITSuME optical observation
  50. GRB060403: XRT refined analysis
  51. GRB 060403: Swift/UVOT upper limits
  52. GRB 060403: Refined analysis of the Swift-BAT burst
  53. GRB 060403: Swift detection of a burst
  54. GRB 060322: LNA optical limit
  55. GRB 060218SN 2006aj: optical observations at Rozhen Observatory
  56. GRB 060323 : WIDGET simultaneous optical observations
  57. GRB 060323: Early optical observation at Xinglong
  58. GRB060218, optical observations
  59. GRB 060322: Confirmation of Swift XRT afterglow
  60. GRB 060211A: optical observation
  61. GRB060323: optical limit
  62. GRB060211B: optical observation
  63. GRB060323: NOT optical observations
  64. GRB 060322: IAC80 optical observations
  65. GRB 060322: Swift XRT afterglow candidate
  66. GRB 060323: Swift/UVOT Observations
  67. GRB 060323: optical afterglow confirmed
  68. GRB060323: NOT observations
  69. GRB 060323: Optical Observations
  70. GRB 060323: Tautenburg OT candidate retraction
  71. GRB 060323: Refined analysis of the Swift-BAT burst
  72. GRB 060323: optical observations at TNG
  73. GRB 060323: Swift XRT refined analysis
  74. GRB 060323: BVRI observations at Tautenburg, aftreglow candidate
  75. GRB 060323: Swift/XRT position
  76. GRB 060322: Refined analysis of the Swift-BAT burst
  77. GRB060323 - SDSS Pre-Burst Observations
  78. GRB 060323: Swift detection of a burst with a possible optical afterglow
  79. GRB 060322: Swift-BAT detection of a 200-sec burst
  80. GRB060219: optical observation
  81. GRB060206: optical observation
  82. GRB060218/SN2006aj: optical observations
  83. GRB 060218/SN 2006aj, LNA optical observation
  84. GRB060218: Refined photometric calibration of comparison stars
  85. GRB 060319: WHT K-band candidate afterglow
  86. GRB 060319: IAC-80 optical observations
  87. GRB060319: Swift XRT refined analysis
  88. GRB 060319: Re-analysis of TNG data
  89. GRB060319: MASTER limit
  90. GRB 060319: Swift-BAT refined analysis
  91. GRB 060319 optical observations at TNG
  92. GRB060319 : Liverpool Telescope optical limit
  93. GRB060319: MASTER optical observation
  94. GRB060319 - SDSS Pre-burst Observations
  95. GRB 060319: Swift detection of a burst
  96. GRB060313: Radio Observations
  97. GRB 060313: early afterglow NIR upper limits with REM
  98. IBAS Alert n. 3221: not a GRB
  99. Konus-Wind observation of GRB 060313
  100. GRB060313: SSO 40inch Observations

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