Willman 1 is a small low surface-brightness object identified in the Sloan Digital Sky Survey and tentatively classified as a very low luminosity dSph galaxy .
Further study has supported this classification while hinting that it may be undergoing disruption by the Milky Way potential .
In an effort to better constrain the nature of Willman 1 , we present a comprehensive analysis of the brightest stars in a 0.6 square degree field centered on the overdensity .
High-resolution HET spectra of two previously identified Willman 1 RGB stars show that one is a metal-rich foreground dwarf while the other is a metal-poor giant .
The one RGB star that we confirm as a member of Willman 1 has a low metallicity ( [ Fe/H ] =-2.2 ) and a surprisingly low \alpha -element abundance ( [ \alpha / Fe ] =-0.11 ) .
Washington+ DDO 51 photometry indicates that 2-5 of the seven brightest Willman 1 stars identified in previous studies are actually dwarf stars , including some of the more metal-rich stars that have been used to argue both for an abundance spread and a more metal-rich stellar population than galaxies of similar luminosity .
The remaining stars are too blue or too faint for photometric classification .
The Washington+ DDO 51 photometry identifies three potential RGB stars in the field but HET spectra show that they are background halo stars .
Time series photometry identifies one apparent variable star in the field , but it is unlikely to be associated with Willman 1 .
Our wide-field survey indicates that over 0.6 square degrees , Willman 1 does not have a single RR Lyrae star , a single BHB star or a single RGB star beyond its tidal radius .
While our results confirm that Willman 1 is most likely a low-luminosity metal-poor dSph galaxy , the possibility remains that it is a tidally disrupted metal-poor globular cluster .