High resolution spectroscopy is used to determine the detailed chemical abundances of a group of eight F- and G-type stars in the young open cluster Blanco 1 .
An average [ Fe/H ] of +0.04 \pm 0.02 ( internal error ) \pm 0.04 ( external error ) is found , considerably lower than a previous spectroscopic estimate for this cluster .
The difference is due mainly to our adoption of significantly cooler temperatures which are consistent with both photometric and spectroscopic constraints .
Blanco 1 exhibits sub-solar [ Ni/Fe ] ( -0.18 \pm 0.01 \pm 0.01 ) , [ Si/Fe ] ( -0.09 \pm 0.02 \pm 0.03 ) , [ Mg/Fe ] ( -0.14 \pm 0.02 \pm 0.03 ) and [ Ca/Fe ] ( -0.09 \pm 0.03 \pm 0.03 ) ; ratios which are not observed among nearby field stars .
The material from which Blanco 1 formed may not have been well mixed with interstellar matter in the galactic disc , which tallies with its current location about 240 pc below the galactic plane .
A simultaneous deficit of Ni and alpha elements with respect to Fe is hard to reconcile with most published models of yields from supernovae of types Ia and II .
The revised abundances for Blanco 1 indicate that overall radiative opacities in its stars , and hence convective zone properties at a given mass , are similar to those in the Pleiades at approximately the same age .
This can explain a previous observation that the Li depletion patterns of G- and K-type stars in the two clusters are indistinguishable .
The lower overall metallicity of Blanco 1 now make it less attractive as a target for discovering transiting , short period exoplanets .