Origin and possible birthplace of the extreme runaway star HIP 60350

¹ Institute of Theoretical Physics, Tartu University, Tähe 4, Tartu 51010, Estonia
² Tartu Observatory, 61602 Tõravere, Estonia
³ Institut für Astronomie der Universität Wien, Türkenschanzstrasse 17, 1180 Wien, Austria
⁴ Astrophysikalisches Institut Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany

Corresponding author: P. Tenjes, tenjes@aai.ee

Received: 28 September 2000
Accepted: 15 December 2000

Abstract

Using the recently determined spatial velocity components of the extreme runaway star HIP 60350 and a gravitation potential model of the Galaxy, we integrate the orbit of HIP 60350 back to the plane of the Galaxy. In this way, a possible location of the formation of the star is determined. We estimate the uncertainty of the result due to the uncertainties of the gravitational potential model and the errors in the spatial velocity components. The place of birth lies (within the errors) near the position of the open cluster NGC 3603. However, the ejection event which occurred about 20 Myr ago is in contradiction with the cluster mean age of Myr. We suggest that it occurred at an earlier phase in sequential star formation in that region. We discuss also ejection mechanisms. Due to the rather high mass of the star (about ), the most probable model is that of dynamical ejection.