Fundamental stellar parameters for nearby visual binary stars: eta Cas, XI Boo, 70 OPH and 85 Peg. Helium abundance, age and mixing length parameter for low mass stars

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

49

Solar Neighbourhood, Hertzsprung-Russel (Hr) And C-M Diagrams, Stars: Fundamental Parameters, Stars: Evolution, Binaries: Visual

Scientific paper

The calibration of nearby visual binary stars on the HR diagram is used to determine the helium abundance, age and mixing length parameter for stars other than the Sun. Four Population I low mass systems with high-quality data are analysed by means of standard evolutionary stellar models: eta Cas, 70 Oph, xi Boo and 85 Peg. Complementing these results with those for the Sun and {alpha_ {MLT}} cen\ it is shown that in the framework of the mixing-length formalism to describe convection, a unique value of the mixing-length parameter, equal to the solar one can be used to model these objects. Except for the 85 Pegasi system, which cannot be explained by means of standard stellar evolutionary models, the helium abundance is determined with a precision of 0.02 (p.e.) and the age with a precision of 2 Gyr (p.e.). A concomitant positive relation between metallicity and helium abundance is found for these stars, corresponding to a mean value of about {Delta Y/Delta Z} {\alphaMLT} pprox 3 +/- 2 (relative helium-to-heavier-elements enrichment parameter) but there is no clear correlation between age and metallicity. The consequences of the results of the use of the new parallaxes from the i HIPPARCOS mission are briefly discussed.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Fundamental stellar parameters for nearby visual binary stars: eta Cas, XI Boo, 70 OPH and 85 Peg. Helium abundance, age and mixing length parameter for low mass stars does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Fundamental stellar parameters for nearby visual binary stars: eta Cas, XI Boo, 70 OPH and 85 Peg. Helium abundance, age and mixing length parameter for low mass stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fundamental stellar parameters for nearby visual binary stars: eta Cas, XI Boo, 70 OPH and 85 Peg. Helium abundance, age and mixing length parameter for low mass stars will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1718208

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.