Name: Albireo
    Other names:  
    Description: Double star
    Ascension:  
    Declanation:  
    Apparent diameter:  
    Constellation:  
    Magnitude: 3.3 and 5.5
    Distance: 380 ly
    Equipment: ETX90 - ICX424 - Barlow 3
    Date / Time UTC: sep 2006
    Stacked :  
    Exposure time: avi
    Location: The Hague, The Netherlands
    Other info: Albireo is actually triple. The brighter yellow-colored member, Albireo A, is a much closer double made of a third magnitude (3.3) class K (K3) stable helium-fusing bright giant and a hotter but dimmer (magnitude 5.5) class B (B9) hydrogen-fusing dwarf, the two stars not readily separable in the telescope. The K giant has a temperature of around 4400 Kelvin, a luminosity 950 times that of the Sun, a radius 50 times solar, and a hefty mass of about 5 solar, while the close companion comes in at 11,000 Kelvin, 100 solar luminosities, and 3.2 solar masses. On average separated by about 40 Astronomical Units, they take almost 100 years to go about each other on a highly eccentric orbit.

     

    © Job Gehéniau

    http://www.jgeheniau.nl/etx90/astronomy2.html

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