Absolute magnitudes and luminosity-related physical parameters of the'solar analog' - candidates 16 CYG A and B.
Abstract
Supposing that 16 Cyg A and B are the components of a binary system and therefore have the same age, upper limits of the luminosity can be derived from the conditions that (1) in a luminosity-Teff diagram both stars should lie on or near the same isochrone and (2) the variations of position angle and apparent distance with time and the difference in radial velocity are the result of the orbital motion. Both methods yield maximum distances to 16 Cyg significantly smaller than the distance following from the trigonometric parallax. A differential treatment of the evolutionary tracks of stars with masses around one solar mass yields for the two stars: age between 7 and 9 billion years, absolute visual magnitudes MA ≈ 4m.26, MB ≈ 4m.50 (M_sun; = 4m.82), masses MA ≈ 0.99 M_sun;, MB ≈ 0.96 M_sun;, radii RA ≈ 1.25 R_sun;, RB ≈ 1.15 R_sun;. As a by-product one obtains also the corresponding data for another 'solar analog'-candidate, namely van Bueren 64: age about 0.8 billion years, M64 = 4m.91, M64 ≈ 1.03 M_sun;, R64 ≈ 0.95 R_sun;.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- October 1986
- Bibcode:
- 1986A&A...167...97N
- Keywords:
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- Binary Stars;
- Color-Magnitude Diagram;
- Stellar Luminosity;
- Stellar Magnitude;
- Stellar Mass;
- Distance;
- H Alpha Line;
- Radial Velocity;
- Stellar Orbits;
- Stellar Temperature;
- Astrophysics