A quantitative spectral analysis of 24 A supergiants in the Sculptor Group spiral galaxy NGC 300 at a distance of 1.9 Mpc is presented .
A new method is introduced to analyze low resolution ( \sim 5 \AA ) spectra , which yields metallicities accurate to 0.2 dex including the uncertainties arising from the errors in T _ { \mbox { \scriptsize \em eff } } ( 5 % ) and log~ { } g ( 0.2 dex ) .
For the first time the stellar metallicity gradient based on elements such as titanium and iron in a galaxy beyond the Local Group is investigated .
Solar metallicity is measured in the center and 0.3 solar in the outskirts and a logarithmic gradient of -0.08 dex/kpc .
An average reddening of E ( B-V ) \sim 0.12 mag is obtained , however with a large variation from 0.07 to 0.24 mag .
We also determine stellar radii , luminosities and masses and discuss the evolutionary status .
Finally , the observed relationship between absolute bolometric magnitudes M _ { bol } and flux weighted gravities g _ { F } = g / T _ { \mbox { \scriptsize \em eff } } ^ { 4 } is investigated .
At high temperatures the strengths of the Balmer lines depends solely on the flux-weighted gravity , which allows a precise direct determination of log~ { } g _ { F } with an accuracy of 0.05 to 0.1 dex .
We find a tight relationship between M _ { bol } and log~ { } g _ { F } in agreement with stellar evolution theory .
Combining these new results with previous work on Local Group galaxies we obtain a new flux weighted gravity luminosity relationship ( FGLR ) , which is very well defined and appears to be an excellent alternative tool to determine distances to galaxies .