Before the Giants: APASS Support to Ambitious Ground-based Galaxy Investigations and Space Missions Serching for Exo-Earths (Abstract)

Volume 43 number 1 (2015)

Ulisse Munari

INAF—Astronomical Observatory of Padova, Vicolo dell’Osservatorio 5, Padova I - 35122, Italy

Abstract

(Abstract only) A huge, worldwide effort is underway to reconstruct the structure, kinematics and evolution of our Galaxy with optical spectroscopic techniques, which provide radial velocities and individual chemical abundances in addition to deriving fundamental stellar parameters like surface temperature and gravity. For ten years (2003–2013) the Radial Velocity Experiment (RAVE) has used the 6dF 150-fiber positioner at the 1.3-meter UK Schmidt telescope in Siding Spring. ESO-Gaia has hundreds of nights allocated at the VLT telescopes in Chile with UVES and GIRAFFE multi-fiber instruments. The Galactic Archaeology with HERMES (GALAH) survey has been allocated 400 nights in five years with the 400-fiber High Efficiency and Resolution Multi-Element Spectrograph (HERMES) at the 4-meter Anglo-Australian Telescope. Common to the millions of stars targeted by these surveys (over the range 10 < V < 16 mag) is the lack of suitable, multi-band, accurate optical photometry. In this talk, I review the fundamental role played by the AAVSO Photometric All-Sky Survey (APASS) in providing such missing photometric information for the stars targeted by these gigantic spectroscopic surveys. The APASS BVgri data are fundamental to support the spectroscopic effort, for example to constrain (when modelled together with 2MASS infrared JHK photometry) the stellar temperature. The APASS data are also crucial in fixing the interstellar reddening and the distance to the target stars, and their importance will be further expanded when APASS ultraviolet (u) and far red (z,Y) magnitudes will become available, as well the unsaturated APASS extension to brighter stars so that most of the bright spectroscopic standards will become within photometric reach.