Parallaxes for W49N and G048.60+0.02: Distant Star Forming Regions in
  the Perseus Spiral Arm
  We report trigonometric parallax measurements of 22 GHz H$_2$O masers in two
massive star-forming regions from VLBA observations as part of the BeSSeL
Survey. The distances of $11.11^{+0.79}_{-0.69}$ kpc to W49N (G043.16+0.01) and
$10.75^{+0.61}_{-0.55}$ kpc to G048.60+0.02 locate them in a distant section of
the Perseus arm near the solar circle in the first Galactic quadrant. This
allows us to locate accurately the inner portion of the Perseus arm for the
first time. Combining the present results with sources measured in the outer
portion of the arm in the second and third quadrants yields a global pitch
angle of 9.5 deg +/- 1.3 deg for the Perseus arm. We have found almost no
H$_2$O maser sources in the Perseus arm for 50 deg $< \ell <$ 80 deg,
suggesting that this $\approx 6$ kpc section of the arm has little massive star
formation activity.
