Testing systematics of Gaia DR2 parallaxes with empirical surface brightness – color relations applied to eclipsing binaries. (arXiv:1902.00589v1 [astro-ph.SR])

Testing systematics of Gaia DR2 parallaxes with empirical surface brightness – color relations applied to eclipsing binaries. (arXiv:1902.00589v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Graczyk_D/0/1/0/all/0/1">Dariusz Graczyk</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pietrzynski_G/0/1/0/all/0/1">Grzegorz Pietrzynski</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gieren_W/0/1/0/all/0/1">Wolfgang Gieren</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Storm_J/0/1/0/all/0/1">Jesper Storm</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nardetto_N/0/1/0/all/0/1">Nicolas Nardetto</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gallenne_A/0/1/0/all/0/1">Alexandre Gallenne</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Maxted_P/0/1/0/all/0/1">Pierre F. L. Maxted</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kervella_P/0/1/0/all/0/1">Pierre Kervella</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kolaczkowski_Z/0/1/0/all/0/1">Zbigniew Kolaczkowski</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Konorski_P/0/1/0/all/0/1">Piotr Konorski</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pilecki_B/0/1/0/all/0/1">Bogumil Pilecki</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zgirski_B/0/1/0/all/0/1">Bartlomiej Zgirski</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gorski_M/0/1/0/all/0/1">Marek Gorski</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Suchomska_K/0/1/0/all/0/1">Ksenia Suchomska</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Karczmarek_P/0/1/0/all/0/1">Paulina Karczmarek</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Taormina_M/0/1/0/all/0/1">Monica Taormina</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wielgorski_P/0/1/0/all/0/1">Piotr Wielgorski</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Narloch_W/0/1/0/all/0/1">Weronika Narloch</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Smolec_R/0/1/0/all/0/1">Radoslaw Smolec</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chini_R/0/1/0/all/0/1">Rolf Chini</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Breuval_L/0/1/0/all/0/1">Louise Breuval</a>

Using a sample of 81 galactic, detached eclipsing binary stars we
investigated the global zero-point shift of their parallaxes with the Gaia Data
Release 2 (DR2) parallaxes. The stars in the sample lay in a distance range of
0.04-2 kpc from the Sun. The photometric parallaxes {pi}_Phot of the eclipsing
binaries were determined by applying a number of empirical surface brightness –
color (SBC) relations calibrated on optical-infrared colors. For each SBC
relation we calculated the individual differences d{pi}_i = ({pi}_Gaia –
{pi}_Phot)_i and then we calculated unweighted and weighted means. As the
sample covers the whole sky we interpret the weighted means as the global
shifts of the Gaia DR2 parallaxes with respect to our eclipsing binary sample.
Depending on the choice of the SBC relation the shifts vary from -0.094 mas to
-0.025 mas. The weighted mean of the zero-point shift from all colors and
calibrations used is d{pi} = -0.054 +/- 0.024 mas. However, the SBC relations
based on (B-K) and (V-K) colors, which are the least reddening dependent and
have the lowest intrinsic dispersions, give a zero-point shift of d{pi} =
-0.031 +/- 0.011 mas in full agreement with results obtained by Lindegren et
al. and Arenou et al. Our result confirms the global shift of Gaia DR2
parallaxes of d{pi} = -0.029 mas reported by the Gaia team, but we do not
confirm the larger zero-point shift reported by a number of follow-up papers.

http://arxiv.org/icons/sfx.gif