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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"

28041 results found.

  1. GRB 050822: Swift-BAT refined analysis
  2. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  3. GRB050820B at FRAM
  4. Swift/UVOT UV Photometry of GRB 050820B
  5. GRB 050822: Swift detection of a long burst
  6. GRB050820a BVRcIc field photometry
  7. GRB050820B XMM-Newton observation
  8. GRB 050820a: NIR Observations by WIRO
  9. GRB 050820B: Swift XRT position
  10. GRB050820B: Refined analysis of the Swift-BAT burst
  11. GRB050820: refined XRT analysis
  12. GRB 050820 Swift-BAT refined analysis
  13. GRB050819: refined XRT analysis
  14. GRB 050820: Swift detection of a GRB
  15. GRB 050819 Swift-BAT refined analysis
  16. GRB050819: Swift-BAT detection of a weak burst
  17. GRB 050817: Optical observations
  18. GRB050817: Negative Optical Observations
  19. GRB 050814: continued fading
  20. GRB050815: Optical afterglow detection by Swift UVOT
  21. GRB050815: XRT refined analysis
  22. GRB050815: Refined analysis of the Swift-BAT burst
  23. GRB 050815: ROTSE-III Optical Limits
  24. GRB050815: Swift-BAT detection of a burst
  25. GRB050814: Fading red source
  26. GRB050814: P60 Optical Afterglow Candidate
  27. GRB 050813: Non-fading of afterglow candidate
  28. GRB 050814: XRT refined analysis
  29. GRB050814: SWIFT/UVOT observation
  30. GRB050814: Refined analysis of the Swift-BAT burst
  31. GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
  32. GRB 050814: Swift XRT Afterglow Localization
  33. GRB 050814: Swift detection of a burst
  34. GRB 050813: Magellan detection of a high redshift galaxy cluster
  35. GRB050813, SDSS pre-burst observations
  36. GRB 050813: Swift-BAT refined analysis
  37. GRB 050813: Photometry of object in XRT error circle
  38. GRB050813: SWIFT/UVOT observation
  39. GRB 050813: Swift XRT afterglow localization
  40. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  41. Detection of an intermediate burst from SGR 1806-20 on August 8
  42. GRB050805b: CrAO optical limit
  43. GRB050803, optical observations
  44. Retraction of Swift Trigger 149131 (GRB 050805B)
  45. GRB 050805b: OHP optical limits
  46. GRB 050805b: TAROT optical limits
  47. GRB050805b: MASTER optical observations
  48. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  49. GRB050805a: MASTER optical candidat
  50. GRB050802: TNG optical observations
  51. GRB050803: Radio Observation
  52. GRB 050803: RTT150 optical observations
  53. GRB050801: Radio Observation
  54. GRB050730: Radio Detection
  55. GRB 050803: Keck Observations
  56. GRB 050803: Swift-BAT refined analysis
  57. GRB 050802.422: Fading of the afterglow and detection of the host
  58. GRB 050803: early Swift XRT analysis results
  59. GRB 050803: TAROT optical limits
  60. GCN GRB observation 050713A
  61. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  62. GRB050802 radio non-detection
  63. GRB 050730: OHP optical observations
  64. GRB 050802: early Swift XRT analysis results
  65. GRB 050802: Swift/UVOT observations
  66. GRB 050802: Swift-BAT refined analysis
  67. GRB050801: Optical photometry and decay index
  68. GRB 050802: Swift Gamma-ray Burst
  69. GRB050801: Swift/UVOT Optical and UV detections
  70. GRB 050730: Preliminary Analysis of MIKE Spectrum
  71. GCN 050801: early Swift XRT analysis results
  72. GRB 050801: Swift-BAT refined analysis
  73. GRB 050730: XRT refined analysis
  74. GRB 050730: early TAROT optical observations
  75. GRB 050730, spectra and optical photometry
  76. GRB050730: Refined BAT analysis of the Swift-BAT burst
  77. GRB 050730 XMM-Newton observation
  78. GRB050730: Swift-BAT detection of a weak burst
  79. GRB050713b: Maidanak optical observations
  80. GRB 050724: Secure Host Redshift from Keck
  81. GRB 050724: WHT optical observations
  82. GRB050713: analysis of the XMM-Newton observation
  83. Swift-BAT trigger 147918 is not a real GRB
  84. GRB050724: VLT observations of the variable source
  85. GRB050709: Second Epoch Chandra Observation
  86. GRB050726: Swift-BAT detection of a weak burst
  87. GRB 050724: Optical Variability in Nearby Galaxy
  88. GRB 050724: J-band observations
  89. GRB 050724: GMOS Imaging and Spectroscopy
  90. GRB050724: Radio Observation
  91. GRB 050724: Optical imaging/astrometry
  92. GRB 050724: Swift/UVOT Upper Limit
  93. GRB050724: Refined analysis of the Swift-BAT possible short burst
  94. GRB 050724: possible host galaxy in DSS
  95. GRB 050721A: Swift-BAT refined analysis
  96. GRB 050721A: Early Swift XRT analysis results
  97. GRB050721A: optical decay
  98. GRB 050721: optical afterglow confirmed
  99. GRB 050709: Refined Spectral and Temporal Properties
  100. GRB050714b: Radio Observation

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