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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"

26506 results found.

  1. GRB050915: Swift/UVOT upper limits
  2. GRB 050915: IR Observations
  3. GRB 050915: Swift XRT refined analysis
  4. GRB 050915: Swift-BAT refined analysis
  5. GRB 050915: Swift detection of a GRB
  6. GRB050911: Upper limit on X-ray afterglow
  7. Swift-BAT trigger 155072 ground analysis
  8. Swift-BAT trigger 155072 is probably not a GRB
  9. GRB 050908: DEIMOS spectrum and further analysis
  10. GRB 050911, optical content of Swift/XRT error box
  11. GRB 050911: Swift-BAT refined analysis
  12. GRB 050911: z~0.16 cluster in the field
  13. GRB050911: Swift-BAT detection of a long burst
  14. GRB 050910a: TAROT early optical limits
  15. WIRO observations in I of GRB 050908
  16. GRB 050906: Possible X-ray Counterpart
  17. GRB050908: Swift/UVOT Early upper limits
  18. GRB050908 : Swift-XRT refined analysis
  19. GRB 050908: Swift-BAT refined analysis
  20. GRB 050908: Optical observations
  21. GRB 050908: Optical Observations
  22. GRB 050908: Swift detection of a burst
  23. GRB 050906: Optical observations at the Very Large Telescope
  24. GRB 050904 BAT refined analysis of complete data set
  25. GRB 050904: Subaru Optical Spectroscopy
  26. GRB 050906: MARGE Optical Limits
  27. GRB 050906: Swift-BAT refined analysis
  28. GRB 050906: Swift XRT upper limit
  29. GRB 050906: Radio Observations
  30. GRB 050904: Keck I-band Imaging
  31. GRB050906: P60 Observations
  32. GRB 050904: more VLT NIR observations
  33. GRB 050904: photometric redshift
  34. GRB 050904: Swift/UVOT observations
  35. GRB 050904: NIR object inside the XRT error box
  36. GRB 050904: early Swift XRT analysis results
  37. GRB 050904: SOAR YJ and PROMPT Ic Observations
  38. GRB050904: Optical Observations
  39. GRB050904: P60 Observations
  40. GRB 050904: TAROT optical limits
  41. GRB 050827 : OSN 1.5m optical observations
  42. GRB 050827: P200 NIR Observations
  43. GRB050827: Swift/UVOT upper limits
  44. GRB 050827: Optical Limit
  45. GRB 050827: XRT possible afterglow detection
  46. GRB 050826 : Lulin R band observation
  47. GRB050824: Maidanak optical limits
  48. GRB 050827: Swift-BAT refined analysis
  49. Subaru Observations of GRB050724
  50. GRB 050826: Optical Candidate
  51. GRB 050826: Swift XRT preliminary analysis results
  52. GRB 050826: BAT refined analysis
  53. GRB050826: Swift/UVOT early upper limits
  54. GRB050826: Swift-BAT detection of a long burst
  55. GRB050824: MASTER final analysis of the OT observations
  56. Swift-BAT trigger 152038 is probably not a GRB
  57. GRB 050824: XRT refined analysis and possible afterglow detection
  58. GRB 050824: BAT refined analysis of a soft weak burst
  59. GRB050824: MASTER:OT decay
  60. GRB050824: MASTER observation OT
  61. GRB050805a: MASTER optical candidat
  62. XRF050509c: Radio upper limits from GMRT
  63. GRB050822: Swift/UVOT upper limits
  64. GRB 050820A BAT observations of second, larger episode of emission
  65. GRB050813: Maidanak I-band observations
  66. GRB 050822: Swift-BAT refined analysis
  67. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  68. GRB050820B at FRAM
  69. Swift/UVOT UV Photometry of GRB 050820B
  70. GRB 050822: Swift detection of a long burst
  71. GRB050820a BVRcIc field photometry
  72. GRB050820B XMM-Newton observation
  73. GRB 050820a: NIR Observations by WIRO
  74. GRB 050820B: Swift XRT position
  75. GRB050820B: Refined analysis of the Swift-BAT burst
  76. GRB050820: refined XRT analysis
  77. GRB 050820 Swift-BAT refined analysis
  78. GRB050819: refined XRT analysis
  79. GRB 050820: Swift detection of a GRB
  80. GRB 050819 Swift-BAT refined analysis
  81. GRB050819: Swift-BAT detection of a weak burst
  82. GRB 050817: Optical observations
  83. GRB050817: Negative Optical Observations
  84. GRB 050814: continued fading
  85. GRB050815: Optical afterglow detection by Swift UVOT
  86. GRB050815: XRT refined analysis
  87. GRB050815: Refined analysis of the Swift-BAT burst
  88. GRB 050815: ROTSE-III Optical Limits
  89. GRB050815: Swift-BAT detection of a burst
  90. GRB050814: Fading red source
  91. GRB050814: P60 Optical Afterglow Candidate
  92. GRB 050813: Non-fading of afterglow candidate
  93. GRB 050814: XRT refined analysis
  94. GRB050814: SWIFT/UVOT observation
  95. GRB050814: Refined analysis of the Swift-BAT burst
  96. GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
  97. GRB 050814: Swift XRT Afterglow Localization
  98. GRB 050814: Swift detection of a burst
  99. GRB 050813: Magellan detection of a high redshift galaxy cluster
  100. GRB050813, SDSS pre-burst observations

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