We report optical spectroscopy of 16 H ii regions in NGC 1705 and [ O iii ] \lambda 4363 detections for the first time in five H ii regions .
The resulting mean oxygen abundance derived directly from measured electron temperatures is 12 + log ( O/H ) = 8.21 \pm 0.05 , which corresponds to [ O/H ] = - 0.45 , or 35 % of the solar value .
There are no significant spatial inhomogeneities in [ O iii ] \lambda 4363 oxygen abundances from H ii regions at a radius approximately 10″ from the super star cluster .
In H ii regions where [ O iii ] \lambda 4363 was not measured , oxygen abundances derived with bright-line methods ( accurate only to 0.2 dex ) are in agreement with direct values of the oxygen abundance .
Faint narrow He II \lambda 4686 emission is found in two H ii regions , but the implied contribution from O ^ { +3 } to the total oxygen abundance is only 0.01 dex .
The mean argon- , neon , and nitrogen-to-oxygen abundance ratios are consistent with mean values for other dwarf irregulars , blue compact dwarf galaxies , and H ii galaxies at comparable oxygen abundances .
Interestingly , the nitrogen-to-oxygen abundance ratio in the ionized H ii gas agrees with the value for the neutral H i , even though the metallicity of the neutral gas may be a factor of six lower than that of the ionized gas .
This may be indicative of low-metallicity gas in the halo of the galaxy .
Extinction values , A _ { V } , derived from observed Balmer line ratios along lines of sight to H ii regions are in the range between zero and 0.9 mag .
Significant and variable extinction may have important effects on the interpretation of resolved stellar populations and derived star formation histories .
With respect to the metallicity-luminosity and metallicity-gas fraction diagnostics , the measured oxygen abundance for NGC 1705 is comparable to Local Group dwarf irregulars at a given luminosity and gas fraction .
Simple chemical evolution models suggest that the galaxy is quickly evolving into a gas-poor dwarf galaxy .