Using the CHARA Array and the Palomar Testbed Interferometer , the chemically peculiar star \lambda Boötis has been spatially resolved .
We have measured the limb darkened angular diameter to be \theta _ { LD } = 0.533 \pm 0.029 mas , corresponding to a linear radius of R _ { \star } = 1.70 \pm 0.10 R _ { \odot } .
The measured angular diameter yields an effective temperature for \lambda Boo of T _ { eff } = 8887 \pm 242 K. Based upon literature surface gravity estimates spanning \log { ( g ) } = 4.0 - 4.2 [ cm s ^ { -2 } ] , we have derived a stellar mass range of M _ { \star } = 1.1 - 1.7 M _ { \odot } .
For a given surface gravity , the linear radius uncertainty contributes approximately \sigma ( M _ { \star } ) = 0.1 - 0.2 M _ { \odot } to the total mass uncertainty .
The uncertainty in the mass ( i.e. , the range of derived masses ) is primarily a result of the uncertainty in the surface gravity .
The upper bound of our derived mass range ( \log ( g ) = 4.2 , M _ { \star } = 1.7 \pm 0.2 M _ { \odot } ) is consistent with 100 - 300 MYr solar-metallicity evolutionary models .
The mid-range of our derived masses ( \log ( g ) = 4.1 , M _ { \star } = 1.3 \pm 0.2 M _ { \odot } ) is consistent with 2 - 3 GYr metal-poor evolutionary models .
A more definitive surface gravity determination is required to determine a more precise mass for \lambda Boo .