Contact information

Ursa Astronomical Association
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00130 Helsinki

Ursa Astronomical Association

Albireo - 29.8.2021 at 23.50 Tampere Observation number 100835

Visibility III / V

Pekka Rautajoki, Tampereen Ursa

For me, the clearest way to detect an object 40 on the Bongaa 100 list, stars of different colors, is to make an observation of an Albireo double star, where the color difference between the components is quite striking. Because Isaac Newton studied the different colors of light in the 1660s, I used a visual copy of Isaac Newton’s small mirror telescope to observe it. Tube manufacturer Vixen introduced this 70mm f / 4 telescope to the astronomy celebration in 2009. The tube requires a table, and orientation was a bit challenging, but even at low magnification, the Albireo components stood out beautifully. #bongaa100

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Additional information
  • Observation target
    • Deep space object
  • Constellation
    • Cygnus
  • Stars
    • Binary star info

      Binary stars are star systems, where there are two stars close each other. Binary stars are classified to optical or physical binaries.

      In optical binary star systems two stars are apparently close each other, but in reality they are located far each other in different distacies.

      In physical binary systems the stars are bound up with gravity and they are orbiting each other. Stellar systems with more than two stars are called multiple star systems.

      Binary star Albireo in Cygnus in composed of blue and yellow star. It is unknown if this of a physical binary. Image Mauri Korpi.


      M40 eli Winnecke 4 on Messierin luetteloon virheellisesti päätynyt tähtipari. Kyseessä on optinen kaksoistähti. Tähdet eivät siis ole fyysisesti lähekkäin. Kuva Tero Hiekkalinna.

      M40 aka Winnecke 4 is stellar pair incorrectly taken into The Messier catalog. It is an optical binary. Image Tero Hiekkalinna.

  • Designation
    • Albireo
  • Magnification
    • 28
Technical information

Vixen Newton replica Telescope, 70mm f / 4, focal length 280mm. 10mm Kellner eyepiece (28x). Daler & Rowney black paper, Derwent crayons.

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