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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"

35324 results found.

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

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