Search for Galactic runaway stars using Gaia Data Release 1 and HIPPARCOS proper motions^★

¹ Centro de Astrobiología, CSIC-INTA, Campus ESAC, Camino Bajo del Castillo s/n, 28 692 Villanueva de la Cañada, Spain
e-mail: jmaiz@cab.inta-csic.es
² Departamento de Astrofísica y Física de la Atmósfera, Universidad Complutense de Madrid, 28 040 Madrid, Spain
³ Departamento de Física y Astronomía, Universidad de La Serena, Av. Cisternas 1200 Norte, La Serena, Chile
⁴ Instituto de Astrofísica de Canarias, 38 200 La Laguna, Tenerife, Spain
⁵ Departamento de Astrofísica, Universidad de La Laguna, 38 205 La Laguna, Tenerife, Spain
⁶ Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Escuela Politécnica Superior, Universidad de Alicante, Carretera San Vicente del Raspeig s/n, 03 690 San Vicente del Raspeig, Spain
⁷ ESA - European Space Astronomy Centre, Camino Bajo del Castillo s/n, 28 692 Villanueva de la Cañada, Spain
⁸ Instituto de Astrofísica de Andalucía-CSIC Glorieta de la Astronomía s/n, 18 008 Granada, Spain

Received: 7 February 2018
Accepted: 20 April 2018

Abstract

Context. The first Gaia Data Release (DR1) significantly improved the previously available proper motions for the majority of the Tycho-2 stars.

Aims. We wish to detect runaway stars using Gaia DR1 proper motions and compare our results with previous searches.

Methods. Runaway O stars and BA supergiants were detected using a 2D proper motion method. The sample was selected using Simbad, spectra from our GOSSS project, literature spectral types, and photometry processed using the code CHORIZOS.

Results. We detect 76 runaway stars, 17 (possibly 19) of them with no prior identification as such, with an estimated detection rate of approximately one half of the real runaway fraction. An age effect appears to be present, with objects of spectral subtype B1 and later having traveled for longer distances than runaways of earlier subtypes. We also tentatively propose that the fraction of runaways is lower among BA supergiants that among O stars, but further studies using future Gaia data releases are needed to confirm this. The frequency of fast rotators is high among runaway O stars, which indicates that a significant fraction of them (and possibly the majority) is produced in supernova explosions.