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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"

28039 results found.

  1. GRB050820B at FRAM
  2. Swift/UVOT UV Photometry of GRB 050820B
  3. GRB 050822: Swift detection of a long burst
  4. GRB050820a BVRcIc field photometry
  5. GRB050820B XMM-Newton observation
  6. GRB 050820a: NIR Observations by WIRO
  7. GRB 050820B: Swift XRT position
  8. GRB050820B: Refined analysis of the Swift-BAT burst
  9. GRB050820: refined XRT analysis
  10. GRB 050820 Swift-BAT refined analysis
  11. GRB050819: refined XRT analysis
  12. GRB 050820: Swift detection of a GRB
  13. GRB 050819 Swift-BAT refined analysis
  14. GRB050819: Swift-BAT detection of a weak burst
  15. GRB 050817: Optical observations
  16. GRB050817: Negative Optical Observations
  17. GRB 050814: continued fading
  18. GRB050815: Optical afterglow detection by Swift UVOT
  19. GRB050815: XRT refined analysis
  20. GRB050815: Refined analysis of the Swift-BAT burst
  21. GRB 050815: ROTSE-III Optical Limits
  22. GRB050815: Swift-BAT detection of a burst
  23. GRB050814: Fading red source
  24. GRB050814: P60 Optical Afterglow Candidate
  25. GRB 050813: Non-fading of afterglow candidate
  26. GRB 050814: XRT refined analysis
  27. GRB050814: SWIFT/UVOT observation
  28. GRB050814: Refined analysis of the Swift-BAT burst
  29. GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
  30. GRB 050814: Swift XRT Afterglow Localization
  31. GRB 050814: Swift detection of a burst
  32. GRB 050813: Magellan detection of a high redshift galaxy cluster
  33. GRB050813, SDSS pre-burst observations
  34. GRB 050813: Swift-BAT refined analysis
  35. GRB 050813: Photometry of object in XRT error circle
  36. GRB050813: SWIFT/UVOT observation
  37. GRB 050813: Swift XRT afterglow localization
  38. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  39. Detection of an intermediate burst from SGR 1806-20 on August 8
  40. GRB050805b: CrAO optical limit
  41. GRB050803, optical observations
  42. Retraction of Swift Trigger 149131 (GRB 050805B)
  43. GRB 050805b: OHP optical limits
  44. GRB 050805b: TAROT optical limits
  45. GRB050805b: MASTER optical observations
  46. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  47. GRB050805a: MASTER optical candidat
  48. GRB050802: TNG optical observations
  49. GRB050803: Radio Observation
  50. GRB 050803: RTT150 optical observations
  51. GRB050801: Radio Observation
  52. GRB050730: Radio Detection
  53. GRB 050803: Keck Observations
  54. GRB 050803: Swift-BAT refined analysis
  55. GRB 050802.422: Fading of the afterglow and detection of the host
  56. GRB 050803: early Swift XRT analysis results
  57. GRB 050803: TAROT optical limits
  58. GCN GRB observation 050713A
  59. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  60. GRB050802 radio non-detection
  61. GRB 050730: OHP optical observations
  62. GRB 050802: early Swift XRT analysis results
  63. GRB 050802: Swift/UVOT observations
  64. GRB 050802: Swift-BAT refined analysis
  65. GRB050801: Optical photometry and decay index
  66. GRB 050802: Swift Gamma-ray Burst
  67. GRB050801: Swift/UVOT Optical and UV detections
  68. GRB 050730: Preliminary Analysis of MIKE Spectrum
  69. GCN 050801: early Swift XRT analysis results
  70. GRB 050801: Swift-BAT refined analysis
  71. GRB 050730: XRT refined analysis
  72. GRB 050730: early TAROT optical observations
  73. GRB 050730, spectra and optical photometry
  74. GRB050730: Refined BAT analysis of the Swift-BAT burst
  75. GRB 050730 XMM-Newton observation
  76. GRB050730: Swift-BAT detection of a weak burst
  77. GRB050713b: Maidanak optical observations
  78. GRB 050724: Secure Host Redshift from Keck
  79. GRB 050724: WHT optical observations
  80. GRB050713: analysis of the XMM-Newton observation
  81. Swift-BAT trigger 147918 is not a real GRB
  82. GRB050724: VLT observations of the variable source
  83. GRB050709: Second Epoch Chandra Observation
  84. GRB050726: Swift-BAT detection of a weak burst
  85. GRB 050724: Optical Variability in Nearby Galaxy
  86. GRB 050724: J-band observations
  87. GRB 050724: GMOS Imaging and Spectroscopy
  88. GRB050724: Radio Observation
  89. GRB 050724: Optical imaging/astrometry
  90. GRB 050724: Swift/UVOT Upper Limit
  91. GRB050724: Refined analysis of the Swift-BAT possible short burst
  92. GRB 050724: possible host galaxy in DSS
  93. GRB 050721A: Swift-BAT refined analysis
  94. GRB 050721A: Early Swift XRT analysis results
  95. GRB050721A: optical decay
  96. GRB 050721: optical afterglow confirmed
  97. GRB 050709: Refined Spectral and Temporal Properties
  98. GRB050714b: Radio Observation
  99. GRB050712: Radio Observations
  100. GRB050713a: Radio Observation

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