3 years ago

Characterising Open Clusters in the solar neigbourhood with the Tycho-Gaia Astrometric Solution.

N. Brouillet, L. Casamiquela, A. Vallenari, R. Sordo, C. Soubiran, A. Krone-Martins, L. Balaguer-Núnez, C. Jordi, T. Cantat-Gaudin, F. Pensabene, A. Moitinho

The Tycho-Gaia Astrometric Solution (TGAS) subset of the first Gaia catalogue contains an unprecedented sample of proper motions and parallaxes for two million stars brighter than G~12 mag. We take advantage of the full astrometric solution available for those stars to identify the members of known open clusters and compute mean cluster parameters using either TGAS or UCAC4 proper motions, and TGAS parallaxes. We apply an unsupervised membership assignment procedure to select high probability cluster members, we use a Bayesian/MCMC technique to fit stellar isochrones to the observed 2MASS JHK$_s$ magnitudes of the member stars and derive cluster parameters (age, metallicity, extinction, distance modulus), and we combine TGAS data with spectroscopic radial velocities to compute full Galactic orbits. We obtain mean astrometric parameters (proper motions and parallaxes) for 129 clusters closer than about 2 kpc, and cluster parameters from isochrone fitting for 26 of them located inside 1 kpc from us. We show the orbital parameters obtained from integrating 36 orbits in a Galactic potential.

Publisher URL: http://arxiv.org/abs/1801.10042

DOI: arXiv:1801.10042v1

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.