Monoceros OB4: a new association in Gaia DR2

Author(s)
P. S. Teixeira, J. Alves, A. Sicilia-Aguilar, A. Scholz, Alvaro Hacar Gonzalez
Abstract

We use Gaia DR2 data to survey the classic Monoceros OB1 region and look for the existence of a dispersed young population, co-moving with the cloud complex. An analysis of the distribution of proper motions reveals a 20-30 Myr association of young stars, about 300-400 pc away from the far side of the Mon OB1 complex, along the same general line of sight. We characterize the new association, Monoceros OB4, and estimate it contains between 1400 and 2500 stars, assuming a standard initial mass function, putting it on par in size with NGC2264. We find from the internal proper motions that Mon OB4 is unbound and expanding. Our results seem to unveil a larger and more complex Monoceros star formation region, suggesting an elongated arrangement that seems to be at least 300 x 60 pc.

Organisation(s)
Department of Astrophysics
External organisation(s)
University of St. Andrews, University of Dundee
Journal
Monthly Notices of the Royal Astronomical Society
Volume
504
Pages
L17-L21
No. of pages
5
ISSN
0035-8711
DOI
https://doi.org/10.1093/mnrasl/slab029
Publication date
2021
Peer reviewed
Yes
Austrian Fields of Science 2012
103004 Astrophysics
Keywords
ASJC Scopus subject areas
Astronomy and Astrophysics, Space and Planetary Science
Portal url
https://ucris.univie.ac.at/portal/en/publications/monoceros-ob4-a-new-association-in-gaia-dr2(efea2d6f-896a-417e-9c7e-b342ddf46409).html