The preliminary statistical analysis of LAMOST DR8 low resolution AFGK stars

TL;DR

This study analyzes LAMOST DR8 low resolution AFGK stars, revealing correlations between stellar parameters and evolutionary stages, and highlights the diversity in metal abundances among different star types.

Contribution

It provides a preliminary statistical analysis of a large star catalog, combining observational data with stellar evolution modeling to identify key stellar properties and evolutionary features.

Findings

Most red giants with low log g have poor metal abundance.

Hot A-type main-sequence stars are generally metal-rich.

The H-R diagram gap area reflects stellar evolution stages.

Abstract

We download the LAMOST DR8 low resolution catalog 6,478,063 AFGK tpye stars and plot the figures of effective temperature, gravitational acceleration, and metal abundance. Some small and medium mass stars are evolved from pre-main sequence or main sequence stage to planetary nebula stage or white dwarf stage by the stellar evolution code \texttt{MESA}. We analyze the observed statistical data and model calculation results, and then obtain some basic conclusions preliminarily. Most red giant and asymptotic giant stars with log$g$ less than 0.85 have poor metal abundance. Most hot A type main-sequence stars are metal rich stars with log$g$ from 3.5 to 4.5. The conclusions are reasonable within a certain error range. The theory of a gap area in the H-R diagram for stellar evolutions of medium mass stars is reflected in the statistical figures. The central core hydrogen burning stage and the central core helium burning stage correspond to the peak structures in the gravitational acceleration statistical figures respectively. The metal abundances among A, F, G, and K type stars have a wide distribution. We can not simply replace the metal abundances of these stars with the metal abundance of the Sun when doing a fine research work.