The ASAS-SN catalogue of variable stars IX: The spectroscopic properties of Galactic variable stars

The All-Sky Automated Survey for Supernovae (ASAS-SN) provides long baseline (${\sim}4$ yrs) $V-$band light curves sources brighter than V$\lesssim17$ mag across the whole sky. We produced V-band a total of ${\sim}61.5$ million and systematically searched these variability. identified ${\sim} 426,000$ variables, including 219,000$ new discoveries. Most (${\sim}74\%$) our discoveries are in Southern hemisphere. Here we use spectroscopic information from LAMOST, GALAH, RAVE, APOGEE to study physical chemical properties variables. find that metal-poor eclipsing binaries have orbital periods shorter metal-rich systems at fixed temperature. rotational variables on main-sequence, red giant branch clump. A substantial fraction (${\gtrsim}80\%$) rotating giants large $v_{\rm rot}$ or NUV excesses also indicative fast rotation. unusual abundances suggestive analysis problems. Semi-regular tend be lower metallicity ($\rm [Fe/H]{\sim}-0.5$) most stars. DR16 temperatures oxygen-rich semi-regular strongly correlated with $W_{RP}-W_{JK}$ color index $\rm T_{eff}\lesssim3800$ K. Using abundance measurements DR16, evidence Mg N enrichment Aluminum pulsation period, where P\gtrsim 60$ days significantly depleted Al.