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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"

26362 results found.

  1. GRB 050827: XRT possible afterglow detection
  2. GRB 050826 : Lulin R band observation
  3. GRB050824: Maidanak optical limits
  4. GRB 050827: Swift-BAT refined analysis
  5. Subaru Observations of GRB050724
  6. GRB 050826: Optical Candidate
  7. GRB 050826: Swift XRT preliminary analysis results
  8. GRB 050826: BAT refined analysis
  9. GRB050826: Swift/UVOT early upper limits
  10. GRB050826: Swift-BAT detection of a long burst
  11. GRB050824: MASTER final analysis of the OT observations
  12. Swift-BAT trigger 152038 is probably not a GRB
  13. GRB 050824: XRT refined analysis and possible afterglow detection
  14. GRB 050824: BAT refined analysis of a soft weak burst
  15. GRB050824: MASTER:OT decay
  16. GRB050824: MASTER observation OT
  17. GRB050805a: MASTER optical candidat
  18. XRF050509c: Radio upper limits from GMRT
  19. GRB050822: Swift/UVOT upper limits
  20. GRB 050820A BAT observations of second, larger episode of emission
  21. GRB050813: Maidanak I-band observations
  22. GRB 050822: Swift-BAT refined analysis
  23. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  24. GRB050820B at FRAM
  25. Swift/UVOT UV Photometry of GRB 050820B
  26. GRB 050822: Swift detection of a long burst
  27. GRB050820a BVRcIc field photometry
  28. GRB050820B XMM-Newton observation
  29. GRB 050820a: NIR Observations by WIRO
  30. GRB 050820B: Swift XRT position
  31. GRB050820B: Refined analysis of the Swift-BAT burst
  32. GRB050820: refined XRT analysis
  33. GRB 050820 Swift-BAT refined analysis
  34. GRB050819: refined XRT analysis
  35. GRB 050820: Swift detection of a GRB
  36. GRB 050819 Swift-BAT refined analysis
  37. GRB050819: Swift-BAT detection of a weak burst
  38. GRB 050817: Optical observations
  39. GRB050817: Negative Optical Observations
  40. GRB 050814: continued fading
  41. GRB050815: Optical afterglow detection by Swift UVOT
  42. GRB050815: XRT refined analysis
  43. GRB050815: Refined analysis of the Swift-BAT burst
  44. GRB 050815: ROTSE-III Optical Limits
  45. GRB050815: Swift-BAT detection of a burst
  46. GRB050814: Fading red source
  47. GRB050814: P60 Optical Afterglow Candidate
  48. GRB 050813: Non-fading of afterglow candidate
  49. GRB 050814: XRT refined analysis
  50. GRB050814: SWIFT/UVOT observation
  51. GRB050814: Refined analysis of the Swift-BAT burst
  52. GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
  53. GRB 050814: Swift XRT Afterglow Localization
  54. GRB 050814: Swift detection of a burst
  55. GRB 050813: Magellan detection of a high redshift galaxy cluster
  56. GRB050813, SDSS pre-burst observations
  57. GRB 050813: Swift-BAT refined analysis
  58. GRB 050813: Photometry of object in XRT error circle
  59. GRB050813: SWIFT/UVOT observation
  60. GRB 050813: Swift XRT afterglow localization
  61. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  62. Detection of an intermediate burst from SGR 1806-20 on August 8
  63. GRB050805b: CrAO optical limit
  64. GRB050803, optical observations
  65. Retraction of Swift Trigger 149131 (GRB 050805B)
  66. GRB 050805b: OHP optical limits
  67. GRB 050805b: TAROT optical limits
  68. GRB050805b: MASTER optical observations
  69. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  70. GRB050805a: MASTER optical candidat
  71. GRB050802: TNG optical observations
  72. GRB050803: Radio Observation
  73. GRB 050803: RTT150 optical observations
  74. GRB050801: Radio Observation
  75. GRB050730: Radio Detection
  76. GRB 050803: Keck Observations
  77. GRB 050803: Swift-BAT refined analysis
  78. GRB 050802.422: Fading of the afterglow and detection of the host
  79. GRB 050803: early Swift XRT analysis results
  80. GRB 050803: TAROT optical limits
  81. GCN GRB observation 050713A
  82. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  83. GRB050802 radio non-detection
  84. GRB 050730: OHP optical observations
  85. GRB 050802: early Swift XRT analysis results
  86. GRB 050802: Swift/UVOT observations
  87. GRB 050802: Swift-BAT refined analysis
  88. GRB050801: Optical photometry and decay index
  89. GRB 050802: Swift Gamma-ray Burst
  90. GRB050801: Swift/UVOT Optical and UV detections
  91. GRB 050730: Preliminary Analysis of MIKE Spectrum
  92. GCN 050801: early Swift XRT analysis results
  93. GRB 050801: Swift-BAT refined analysis
  94. GRB 050730: XRT refined analysis
  95. GRB 050730: early TAROT optical observations
  96. GRB 050730, spectra and optical photometry
  97. GRB050730: Refined BAT analysis of the Swift-BAT burst
  98. GRB 050730 XMM-Newton observation
  99. GRB050730: Swift-BAT detection of a weak burst
  100. GRB050713b: Maidanak optical observations

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