Monoceros OB4 : a new association in Gaia DR2
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 IMF, putting it on par in size with NGC 2264. 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 × 60 pc.
Citation
Teixeira , P S , Alves , J , Sicilia-Aguilar , A , Hacar , A & Scholz , A 2021 , ' Monoceros OB4 : a new association in Gaia DR2 ' , Monthly Notices of the Royal Astronomical Society: Letters , vol. 504 , no. 1 , pp. L17–L21 . https://doi.org/10.1093/mnrasl/slab029
Publication
Monthly Notices of the Royal Astronomical Society: Letters
Status
Peer reviewed
ISSN
1745-3925Type
Journal article
Description
Funding: This project was supported by STFC grant ST/R000824/1. ASA is partly supported by STFC grant ST/S000399/1. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (Grant agreement No. 851435).Collections
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