23. The Spectrum of Bootis
The spectral type of Boo is near A0, as far as can be determined. The spectral lines, while not unusually broad, are very weak, so that the only features easily visible are a weak K line and the Balmer series of hydrogen. The trigonometric parallax indicates that the star is probably located below the main sequence. The star Hya has similar, but less pronounced, spectral peculiarities. It may be a high-velocity star.