{
  "id": "1501.04404",
  "version": "v1",
  "published": "2015-01-19T06:32:27.000Z",
  "updated": "2015-01-19T06:32:27.000Z",
  "title": "Bayesian Ages for Early-Type Stars from Isochrones Including Rotation, and a Possible Old Age for the Hyades",
  "authors": [
    "Timothy D. Brandt",
    "Chelsea X. Huang"
  ],
  "comment": "11 pages, 6 figures, ApJ submitted",
  "categories": [
    "astro-ph.SR"
  ],
  "abstract": "We combine recently computed models of stellar evolution using a new treatment of rotation with a Bayesian statistical framework to constrain the ages and other properties of early-type stars. We find good agreement for early-type stars and clusters with known young ages, including beta Pictoris and the Pleiades. However, we derive a slightly older age for the Ursa Majoris moving group (600+/-100 Myr compared to 500+/-100 Myr), and a much older age for the Hyades open cluster (950+/-100 Myr compared to 625+/-50 Myr). These older ages result from both the increase in main-sequence lifetime with stellar rotation and from the fact that rotating models near the main-sequence turnoff are more luminous, overlapping with slightly more massive (and shorter-lived) nonrotating ones. The dramatically older age inferred for the Hyades requires a major reevaluation either of the cluster age or of the rotating stellar models. Our method uses a large grid of nonrotating models to interpolate between a much sparser rotating grid, and also includes a detailed calculation of synthetic magnitudes as a function of orientation. We provide a web interface at www.bayesianstellarparameters.info, where the results of our analysis may be downloaded for individual early-type (B-V < 0.25) Hipparcos stars. The web interface accepts user-supplied parameters for a Gaussian metallicity prior and returns posterior probability distributions on mass, age, and orientation.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2015-01-19T06:32:27.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "early-type stars",
      "old age",
      "bayesian ages",
      "web interface accepts user-supplied parameters",
      "isochrones"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 11,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2015arXiv150104404B"
    }
  }
}