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Title: WIYN open cluster study. LXII. Comparison of isochrone systems using deep multi-band photometry of M35

Journal Article · · Astronomical Journal (New York, N.Y. Online)
;  [1];  [2];  [3]
  1. Texas Christian University, Fort Worth, TX 76129 (United States)
  2. Apache Point Observatory, Sunspot, NM 88349 (United States)
  3. University of Florida, Gainesville, FL 32611 (United States)

The current generation of stellar isochrone models exhibits non-negligible discrepancies due to variations in the input physics. The success of each model is determined by how well it fits the observations, and this paper aims to disentangle contributions from the various physical inputs. New deep, wide-field optical and near-infrared photometry (UBVRIJHK{sub S} ) of the cluster M35 is presented, against which several isochrone systems are compared: Padova, PARSEC, Dartmouth, and Y {sup 2}. Two different atmosphere models are applied to each isochrone: ATLAS9 and BT-Settl. For any isochrone set and atmosphere model, observed data are accurately reproduced for all stars more massive than 0.7 M {sub ☉}. For stars less massive than 0.7 M {sub ☉}, Padova and PARSEC isochrones consistently produce higher temperatures than observed. Dartmouth and Y{sup 2} isochrones with BT-Settl atmospheres reproduce optical data accurately; however, they appear too blue in IR colors. It is speculated that molecular contributions to stellar spectra in the near-infrared may not be fully explored, and that future study may reconcile these differences.

OSTI ID:
22342229
Journal Information:
Astronomical Journal (New York, N.Y. Online), Vol. 148, Issue 5; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1538-3881
Country of Publication:
United States
Language:
English