RR Lyrae stars in the Gaia era

TL;DR

This paper reviews Gaia's mission to observe and analyze RR Lyrae stars, highlighting early results and the potential for new discoveries in the Galactic halo and bulge.

Contribution

It provides an overview of Gaia's capabilities and initial findings related to RR Lyrae stars, emphasizing the mission's expected impact on stellar astrophysics.

Findings

Preliminary RR Lyrae observations in the Large Magellanic Cloud

Gaia's expected detection of over 100,000 RR Lyrae stars

Parallax measurements with 10 μas accuracy for bright stars

Abstract

Gaia, the European Space Agency spacecraft successfully launched on 19 December 2013, entered into nominal science operations on 18 July 2014 after a few months of commissioning, and has been scanning the sky to a faint limit of G = 20.7 mag since then. Gaia is expected to observe more than a hundred thousand RR Lyrae stars in the Galactic halo and bulge (most of which will be new discoveries), and to provide parallax measurements with about 10 {\mu}as uncertainty for those brighter than <V>$\sim$ 12-13 mag. Status and activities of the spacecraft since launch are briefly reviewed with emphasis on preliminary results obtained for RR Lyrae stars observed in the Large Magellanic Cloud during the first 28 days of science operations spent in Ecliptic Pole scanning mode and in light of the first Gaia data release which is scheduled for summer 2016.