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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"

28056 results found.

  1. GRB 050826: Swift XRT preliminary analysis results
  2. GRB 050826: BAT refined analysis
  3. GRB050826: Swift/UVOT early upper limits
  4. GRB050826: Swift-BAT detection of a long burst
  5. GRB050824: MASTER final analysis of the OT observations
  6. Swift-BAT trigger 152038 is probably not a GRB
  7. GRB 050824: XRT refined analysis and possible afterglow detection
  8. GRB 050824: BAT refined analysis of a soft weak burst
  9. GRB050824: MASTER:OT decay
  10. GRB050824: MASTER observation OT
  11. GRB050805a: MASTER optical candidat
  12. XRF050509c: Radio upper limits from GMRT
  13. GRB050822: Swift/UVOT upper limits
  14. GRB 050820A BAT observations of second, larger episode of emission
  15. GRB050813: Maidanak I-band observations
  16. GRB 050822: Swift-BAT refined analysis
  17. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  18. GRB050820B at FRAM
  19. Swift/UVOT UV Photometry of GRB 050820B
  20. GRB 050822: Swift detection of a long burst
  21. GRB050820a BVRcIc field photometry
  22. GRB050820B XMM-Newton observation
  23. GRB 050820a: NIR Observations by WIRO
  24. GRB 050820B: Swift XRT position
  25. GRB050820B: Refined analysis of the Swift-BAT burst
  26. GRB050820: refined XRT analysis
  27. GRB 050820 Swift-BAT refined analysis
  28. GRB050819: refined XRT analysis
  29. GRB 050820: Swift detection of a GRB
  30. GRB 050819 Swift-BAT refined analysis
  31. GRB050819: Swift-BAT detection of a weak burst
  32. GRB 050817: Optical observations
  33. GRB050817: Negative Optical Observations
  34. GRB 050814: continued fading
  35. GRB050815: Optical afterglow detection by Swift UVOT
  36. GRB050815: XRT refined analysis
  37. GRB050815: Refined analysis of the Swift-BAT burst
  38. GRB 050815: ROTSE-III Optical Limits
  39. GRB050815: Swift-BAT detection of a burst
  40. GRB050814: Fading red source
  41. GRB050814: P60 Optical Afterglow Candidate
  42. GRB 050813: Non-fading of afterglow candidate
  43. GRB 050814: XRT refined analysis
  44. GRB050814: SWIFT/UVOT observation
  45. GRB050814: Refined analysis of the Swift-BAT burst
  46. GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
  47. GRB 050814: Swift XRT Afterglow Localization
  48. GRB 050814: Swift detection of a burst
  49. GRB 050813: Magellan detection of a high redshift galaxy cluster
  50. GRB050813, SDSS pre-burst observations
  51. GRB 050813: Swift-BAT refined analysis
  52. GRB 050813: Photometry of object in XRT error circle
  53. GRB050813: SWIFT/UVOT observation
  54. GRB 050813: Swift XRT afterglow localization
  55. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  56. Detection of an intermediate burst from SGR 1806-20 on August 8
  57. GRB050805b: CrAO optical limit
  58. GRB050803, optical observations
  59. Retraction of Swift Trigger 149131 (GRB 050805B)
  60. GRB 050805b: OHP optical limits
  61. GRB 050805b: TAROT optical limits
  62. GRB050805b: MASTER optical observations
  63. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  64. GRB050805a: MASTER optical candidat
  65. GRB050802: TNG optical observations
  66. GRB050803: Radio Observation
  67. GRB 050803: RTT150 optical observations
  68. GRB050801: Radio Observation
  69. GRB050730: Radio Detection
  70. GRB 050803: Keck Observations
  71. GRB 050803: Swift-BAT refined analysis
  72. GRB 050802.422: Fading of the afterglow and detection of the host
  73. GRB 050803: early Swift XRT analysis results
  74. GRB 050803: TAROT optical limits
  75. GCN GRB observation 050713A
  76. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  77. GRB050802 radio non-detection
  78. GRB 050730: OHP optical observations
  79. GRB 050802: early Swift XRT analysis results
  80. GRB 050802: Swift/UVOT observations
  81. GRB 050802: Swift-BAT refined analysis
  82. GRB050801: Optical photometry and decay index
  83. GRB 050802: Swift Gamma-ray Burst
  84. GRB050801: Swift/UVOT Optical and UV detections
  85. GRB 050730: Preliminary Analysis of MIKE Spectrum
  86. GCN 050801: early Swift XRT analysis results
  87. GRB 050801: Swift-BAT refined analysis
  88. GRB 050730: XRT refined analysis
  89. GRB 050730: early TAROT optical observations
  90. GRB 050730, spectra and optical photometry
  91. GRB050730: Refined BAT analysis of the Swift-BAT burst
  92. GRB 050730 XMM-Newton observation
  93. GRB050730: Swift-BAT detection of a weak burst
  94. GRB050713b: Maidanak optical observations
  95. GRB 050724: Secure Host Redshift from Keck
  96. GRB 050724: WHT optical observations
  97. GRB050713: analysis of the XMM-Newton observation
  98. Swift-BAT trigger 147918 is not a real GRB
  99. GRB050724: VLT observations of the variable source
  100. GRB050709: Second Epoch Chandra Observation

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