51 Pegasi

 

 

Distance from Earth:

16.7 light years

Star name, type:

Altair, white main sequence star A7V

Star mass, radii:

1.50, 1.60 x Sol

Notes:

-

Hypothetical planet location:

3.5 AU

Possible life:

less than 5%

 

Image description: Even if we put a planet to orbit this star at 3.5 AU, the problem comes from the invisible part of light, called ultra-violet which is very strong for this type of stars (spectral type A). Also, strong stellar winds could damage the atmosphere and make UV rays even more powerful in their destruction. Maybe some bacteria could live below planet's surface. Even if life starts below the surface, the star will become red giant in next 1 billion years, which is not enough for life to develop.

 

This is the main reason why O, B and A spectral type stars are excluded from the "search for life". It would take 5 years 6 months for our Earth sized planet to finish one orbit around this star, at approx. speed of 19,6 km/sec.

 

On this picture, Altair has a shape of flatten ellipsoid. It comes from star's high rotational speed - the star makes one turn in 10 hours - compared with Sun's rotational speed of 26.5 days!

 

More info about Altair System