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Ursa Astronomical Association
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Ursa Astronomical Association

Alpheratz - 1.9.2021 at 22.45 Helsinki Observation number 100884

Visibility III / V

Tuomas Salo, Ursa (Helsinki)

I photographed a blue-and-white spectroscopic binary star in the constellation of Andromeda. It is a variable with a brightness ranging from + 2.02 to + 2.06 over a 23.19 hour period. It belongs to the Pegasus square. Image stacked with DeeSkyStacker.

More similar observations
Additional information
  • Observation target
    • Deep space object
  • Constellation
    • Andromeda
  • Darkness
    • Good
  • Seeing
    • Good
  • 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
    • Alpheratz
  • Weather
    • Sää oli selkeä.
Technical information

Camera Nikon D5100. Lens sigma 400mm tele. Tripod Gitza Gilux Reporter.

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