VLBA determination of the distance to nearby star-forming regions II. Hubble 4 and HDE 283572 in Taurus

TL;DR

This study uses VLBA radio observations to precisely measure the distances to two stars in Taurus, refining the overall distance estimate to the star-forming region with high accuracy.

Contribution

It provides highly accurate VLBA-based distance measurements to Hubble 4 and HDE 283572, improving the understanding of Taurus's spatial structure.

Findings

Distances to Hubble 4 and HDE 283572 are 132.8 and 128.5 parsecs.

The mean distance to Taurus is estimated at 137 parsecs.

The depth of Taurus is approximately 20 parsecs.

Abstract

The non-thermal 3.6 cm radio continuum emission from the naked T Tauri stars Hubble 4 and HDE 283572 in Taurus has been observed with the Very Long Baseline Array (VLBA) at 6 epochs between September 2004 and December 2005 with a typical separation between successive observations of 3 months. Thanks to the remarkably accurate astrometry delivered by the VLBA, the trajectory described by both stars on the plane of the sky could be traced very precisely, and modeled as the superposition of their trigonometric parallax and uniform proper motion. The best fits yield distances to Hubble 4 and HDE 283572 of 132.8 +/- 0.5 and 128.5 +/- 0.6 pc, respectively. Combining these results with the other two existing VLBI distance determinations in Taurus, we estimate the mean distance to the Taurus association to be 137 pc with a dispersion (most probably reflecting the depth of the complex) of about 20 pc.