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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"

28090 results found.

  1. GRB050908: Swift/UVOT Early upper limits
  2. GRB050908 : Swift-XRT refined analysis
  3. GRB 050908: Swift-BAT refined analysis
  4. GRB 050908: Optical observations
  5. GRB 050908: Optical Observations
  6. GRB 050908: Swift detection of a burst
  7. GRB 050906: Optical observations at the Very Large Telescope
  8. GRB 050904 BAT refined analysis of complete data set
  9. GRB 050904: Subaru Optical Spectroscopy
  10. GRB 050906: MARGE Optical Limits
  11. GRB 050906: Swift-BAT refined analysis
  12. GRB 050906: Swift XRT upper limit
  13. GRB 050906: Radio Observations
  14. GRB 050904: Keck I-band Imaging
  15. GRB050906: P60 Observations
  16. GRB 050904: more VLT NIR observations
  17. GRB 050904: photometric redshift
  18. GRB 050904: Swift/UVOT observations
  19. GRB 050904: NIR object inside the XRT error box
  20. GRB 050904: early Swift XRT analysis results
  21. GRB 050904: SOAR YJ and PROMPT Ic Observations
  22. GRB050904: Optical Observations
  23. GRB050904: P60 Observations
  24. GRB 050904: TAROT optical limits
  25. GRB 050827 : OSN 1.5m optical observations
  26. GRB 050827: P200 NIR Observations
  27. GRB050827: Swift/UVOT upper limits
  28. GRB 050827: Optical Limit
  29. GRB 050827: XRT possible afterglow detection
  30. GRB 050826 : Lulin R band observation
  31. GRB050824: Maidanak optical limits
  32. GRB 050827: Swift-BAT refined analysis
  33. Subaru Observations of GRB050724
  34. GRB 050826: Optical Candidate
  35. GRB 050826: Swift XRT preliminary analysis results
  36. GRB 050826: BAT refined analysis
  37. GRB050826: Swift/UVOT early upper limits
  38. GRB050826: Swift-BAT detection of a long burst
  39. GRB050824: MASTER final analysis of the OT observations
  40. Swift-BAT trigger 152038 is probably not a GRB
  41. GRB 050824: XRT refined analysis and possible afterglow detection
  42. GRB 050824: BAT refined analysis of a soft weak burst
  43. GRB050824: MASTER:OT decay
  44. GRB050824: MASTER observation OT
  45. GRB050805a: MASTER optical candidat
  46. XRF050509c: Radio upper limits from GMRT
  47. GRB050822: Swift/UVOT upper limits
  48. GRB 050820A BAT observations of second, larger episode of emission
  49. GRB050813: Maidanak I-band observations
  50. GRB 050822: Swift-BAT refined analysis
  51. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  52. GRB050820B at FRAM
  53. Swift/UVOT UV Photometry of GRB 050820B
  54. GRB 050822: Swift detection of a long burst
  55. GRB050820a BVRcIc field photometry
  56. GRB050820B XMM-Newton observation
  57. GRB 050820a: NIR Observations by WIRO
  58. GRB 050820B: Swift XRT position
  59. GRB050820B: Refined analysis of the Swift-BAT burst
  60. GRB050820: refined XRT analysis
  61. GRB 050820 Swift-BAT refined analysis
  62. GRB050819: refined XRT analysis
  63. GRB 050820: Swift detection of a GRB
  64. GRB 050819 Swift-BAT refined analysis
  65. GRB050819: Swift-BAT detection of a weak burst
  66. GRB 050817: Optical observations
  67. GRB050817: Negative Optical Observations
  68. GRB 050814: continued fading
  69. GRB050815: Optical afterglow detection by Swift UVOT
  70. GRB050815: XRT refined analysis
  71. GRB050815: Refined analysis of the Swift-BAT burst
  72. GRB 050815: ROTSE-III Optical Limits
  73. GRB050815: Swift-BAT detection of a burst
  74. GRB050814: Fading red source
  75. GRB050814: P60 Optical Afterglow Candidate
  76. GRB 050813: Non-fading of afterglow candidate
  77. GRB 050814: XRT refined analysis
  78. GRB050814: SWIFT/UVOT observation
  79. GRB050814: Refined analysis of the Swift-BAT burst
  80. GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
  81. GRB 050814: Swift XRT Afterglow Localization
  82. GRB 050814: Swift detection of a burst
  83. GRB 050813: Magellan detection of a high redshift galaxy cluster
  84. GRB050813, SDSS pre-burst observations
  85. GRB 050813: Swift-BAT refined analysis
  86. GRB 050813: Photometry of object in XRT error circle
  87. GRB050813: SWIFT/UVOT observation
  88. GRB 050813: Swift XRT afterglow localization
  89. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  90. Detection of an intermediate burst from SGR 1806-20 on August 8
  91. GRB050805b: CrAO optical limit
  92. GRB050803, optical observations
  93. Retraction of Swift Trigger 149131 (GRB 050805B)
  94. GRB 050805b: OHP optical limits
  95. GRB 050805b: TAROT optical limits
  96. GRB050805b: MASTER optical observations
  97. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  98. GRB050805a: MASTER optical candidat
  99. GRB050802: TNG optical observations
  100. GRB050803: Radio Observation

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