G-star astropauses - A test for interstellar pressure

Abstract

Under the assumption of a solar system model, astropause radii are estimated for a sample of 70 G stars near the sun. G-star space velocities and trajectories are calculated. Three stars within 10 pc of the sun have predicted astropause radii larger than 6 arcsec. At least eight stars have traversed low interstellar pressure regions, similar to the path of the sun, over the last 4 Myr. The Galactic influences on these stellar systems thus may be similar to those on the solar system, providing a list of possibly attractive SETI targets. The closest star to the sun 4 Myr ago, in this restricted sample, was HD 147513. The relative dimensions of the astropause radii of G stars with space motions parallel and perpendicular to the surrounding interstellar magnetic field may vary by a factor of 2 and may ultimately yield quantitative estimates of interstellar magnetic field strength near the sun.