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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"

26351 results found.

  1. Swift-BAT trigger 152038 is probably not a GRB
  2. GRB 050824: XRT refined analysis and possible afterglow detection
  3. GRB 050824: BAT refined analysis of a soft weak burst
  4. GRB050824: MASTER:OT decay
  5. GRB050824: MASTER observation OT
  6. GRB050805a: MASTER optical candidat
  7. XRF050509c: Radio upper limits from GMRT
  8. GRB050822: Swift/UVOT upper limits
  9. GRB 050820A BAT observations of second, larger episode of emission
  10. GRB050813: Maidanak I-band observations
  11. GRB 050822: Swift-BAT refined analysis
  12. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  13. GRB050820B at FRAM
  14. Swift/UVOT UV Photometry of GRB 050820B
  15. GRB 050822: Swift detection of a long burst
  16. GRB050820a BVRcIc field photometry
  17. GRB050820B XMM-Newton observation
  18. GRB 050820a: NIR Observations by WIRO
  19. GRB 050820B: Swift XRT position
  20. GRB050820B: Refined analysis of the Swift-BAT burst
  21. GRB050820: refined XRT analysis
  22. GRB 050820 Swift-BAT refined analysis
  23. GRB050819: refined XRT analysis
  24. GRB 050820: Swift detection of a GRB
  25. GRB 050819 Swift-BAT refined analysis
  26. GRB050819: Swift-BAT detection of a weak burst
  27. GRB 050817: Optical observations
  28. GRB050817: Negative Optical Observations
  29. GRB 050814: continued fading
  30. GRB050815: Optical afterglow detection by Swift UVOT
  31. GRB050815: XRT refined analysis
  32. GRB050815: Refined analysis of the Swift-BAT burst
  33. GRB 050815: ROTSE-III Optical Limits
  34. GRB050815: Swift-BAT detection of a burst
  35. GRB050814: Fading red source
  36. GRB050814: P60 Optical Afterglow Candidate
  37. GRB 050813: Non-fading of afterglow candidate
  38. GRB 050814: XRT refined analysis
  39. GRB050814: SWIFT/UVOT observation
  40. GRB050814: Refined analysis of the Swift-BAT burst
  41. GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
  42. GRB 050814: Swift XRT Afterglow Localization
  43. GRB 050814: Swift detection of a burst
  44. GRB 050813: Magellan detection of a high redshift galaxy cluster
  45. GRB050813, SDSS pre-burst observations
  46. GRB 050813: Swift-BAT refined analysis
  47. GRB 050813: Photometry of object in XRT error circle
  48. GRB050813: SWIFT/UVOT observation
  49. GRB 050813: Swift XRT afterglow localization
  50. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  51. Detection of an intermediate burst from SGR 1806-20 on August 8
  52. GRB050805b: CrAO optical limit
  53. GRB050803, optical observations
  54. Retraction of Swift Trigger 149131 (GRB 050805B)
  55. GRB 050805b: OHP optical limits
  56. GRB 050805b: TAROT optical limits
  57. GRB050805b: MASTER optical observations
  58. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  59. GRB050805a: MASTER optical candidat
  60. GRB050802: TNG optical observations
  61. GRB050803: Radio Observation
  62. GRB 050803: RTT150 optical observations
  63. GRB050801: Radio Observation
  64. GRB050730: Radio Detection
  65. GRB 050803: Keck Observations
  66. GRB 050803: Swift-BAT refined analysis
  67. GRB 050802.422: Fading of the afterglow and detection of the host
  68. GRB 050803: early Swift XRT analysis results
  69. GRB 050803: TAROT optical limits
  70. GCN GRB observation 050713A
  71. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  72. GRB050802 radio non-detection
  73. GRB 050730: OHP optical observations
  74. GRB 050802: early Swift XRT analysis results
  75. GRB 050802: Swift/UVOT observations
  76. GRB 050802: Swift-BAT refined analysis
  77. GRB050801: Optical photometry and decay index
  78. GRB 050802: Swift Gamma-ray Burst
  79. GRB050801: Swift/UVOT Optical and UV detections
  80. GRB 050730: Preliminary Analysis of MIKE Spectrum
  81. GCN 050801: early Swift XRT analysis results
  82. GRB 050801: Swift-BAT refined analysis
  83. GRB 050730: XRT refined analysis
  84. GRB 050730: early TAROT optical observations
  85. GRB 050730, spectra and optical photometry
  86. GRB050730: Refined BAT analysis of the Swift-BAT burst
  87. GRB 050730 XMM-Newton observation
  88. GRB050730: Swift-BAT detection of a weak burst
  89. GRB050713b: Maidanak optical observations
  90. GRB 050724: Secure Host Redshift from Keck
  91. GRB 050724: WHT optical observations
  92. GRB050713: analysis of the XMM-Newton observation
  93. Swift-BAT trigger 147918 is not a real GRB
  94. GRB050724: VLT observations of the variable source
  95. GRB050709: Second Epoch Chandra Observation
  96. GRB050726: Swift-BAT detection of a weak burst
  97. GRB 050724: Optical Variability in Nearby Galaxy
  98. GRB 050724: J-band observations
  99. GRB 050724: GMOS Imaging and Spectroscopy
  100. GRB050724: Radio Observation

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