We present new statistical parallax solutions for the absolute magnitude and kinematics of RR Lyrae stars. We have combined new proper motions from the Lick Northern Proper Motion program with new radial velocity and abundance measures to produce a data set that is 50% larger, and of higher quality, than the data sets employed by previous analyses. Based on an a priori kinematic study, we separated the stars into halo and thick disk sub-populations. We performed statistical parallax solutions on these sub-samples, and found M V (RR) = +0.71 ± 0.12 at [Fe/H] = -1.61 for the halo (162 stars), and M V (RR) = +0.79 ± 0.30 at [Fe/H] = -0.76 for the thick disk (51 stars). The solutions yielded a solar motion V = −210 ± 12 km s −1 and velocity ellipsoid (σ U , σ V , σ W ) = (168 ± 13, 102 ± 8, 97 ± 7) km s −1 for the halo. The values were V = −48 ± 9 km s −1 and (σ U , σ V , σ W ) = (56 ± 8, 51 ± 8, 31 ± 5) km s −1 for 1 NSF Young Investigator -2the thick disk. Both are in good agreement with estimates of the halo and thick disk kinematics derived from both RR Lyrae stars and other stellar tracers. Monte Carlo simulations indicated that the solutions are accurate, and that the errors may be smaller than the estimates above. The simulations revealed a small bias in the disk solutions, and appropriate corrections were derived. The large uncertainty in the disk M V (RR) prevents ascertaining the slope of the M V (RR)-[Fe/H] relation. Using a zero point defined by our halo solution and adopting a slope of 0.15 mag dex −1 , we find that (1) the distance to the Galactic Center is 7.6 ± 0.4 kpc; (2) the mean age of the 17 oldest Galactic globular clusters is 16.5 +2.1 −1.9 Gyr; and (3) the distance modulus of the LMC is 18.28 ± 0.13 mag. Estimates of H 0 which are based on an LMC distance modulus of 18.50 (e.g., Cepheid studies) increase by 10% if they are recalibrated to match our LMC distance modulus.However, the zero-point of the relationship continues to defy a consensus. At the characteristic abundance of the halo, [Fe/H] = -1.6, M V (RR) values range from 0.45 to 0.75 mag, and usually fall either toward the brighter or the fainter end of this range. Chaboyer (1995) showed that this "two value" effect translates to a ∼22% difference in the derived ages of the Galactic globular clusters, and in fact represents the dominant uncertainty in the determination of cluster ages.

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We report astrometric parallaxes for three well known dwarf novae obtained using the Fine Guidance Sensors on the Hubble Space Telescope. We found a parallax for SS Aurigae of π = 5.00 ± 0.64 mas, for SS Cygni we found π = 6.02 ± 0.46 mas, and for U Geminorum we obtained π = 10.37 ± 0.50 mas.These represent the first true trigonometric parallaxes of any dwarf novae. We briefly compare these results with previous distance estimates. This program demonstrates that with a very modest amount of HST observing time, the Fine Guidance Sensors can deliver parallaxes of unrivaled precision.

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