The Distances to Open Clusters from Main-Sequence Fitting. III. Improved Accuracy with Empirically Calibrated Isochrones
| dc.creator | An, Deokkeun | |
| dc.creator | Terndrup, Donald M. | |
| dc.creator | Pinsonneault, Marc H. | |
| dc.creator | Paulson, Diane B. | |
| dc.creator | Hanson, Robert B. | |
| dc.creator | Stauffer, John R. | |
| dc.date | 2006-07-24 | |
| dc.date | 2007-01-13 | |
| dc.date.accessioned | 2026-07-07T10:39:39Z | |
| dc.date.available | 2026-07-07T10:39:39Z | |
| dc.description | We continue our series of papers on open cluster distances with a critical assessment of the accuracy of main-sequence fitting using isochrones that employ empirical corrections to the color-temperature relations. We use four nearby open clusters with multicolor photometry and accurate metallicities and present a new metallicity for Praesepe ([Fe/H] = +0.11 +/- 0.03) from high-resolution spectra. The internal precision of distance estimates is about a factor of 5 better than the case without the color calibrations. After taking into account all major systematic errors, we obtain distances accurate to about 2%-3% when there exists a good metallicity estimate. Metallicities accurate to better than 0.1 dex may be obtained from BVIcKs photometry alone. We also derive a helium abundance for the Pleiades of Y = 0.279 +/- 0.015, which is equal within the errors to the Sun's initial helium abundance and that of the Hyades. Our best estimates of distances are (m - M)_0 = 6.33 +/- 0.04, 8.03 +/- 0.04, and 9.61 +/- 0.03 to Praesepe, NGC 2516, and M67, respectively. Our Pleiades distance at the spectroscopic metallicity, (m - M)_0 = 5.66 +/- 0.01 (internal) +/- 0.05 (systematic), is in excellent agreement with several geometric distance measurements. We have made calibrated isochrones for -0.3 <= [Fe/H] <= +0.2 available at http://www.astronomy.ohio-state.edu/iso/ . | |
| dc.description | 28 pages, 23 figures; accepted for publication in the ApJ | |
| dc.identifier | https://arxiv.org/abs/astro-ph/0607549 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/0607549 | |
| dc.identifier | Astrophys.J.655:233-260,2007 | |
| dc.identifier | doi:10.1086/509653 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/181104 | |
| dc.subject | Astrophysics | |
| dc.title | The Distances to Open Clusters from Main-Sequence Fitting. III. Improved Accuracy with Empirically Calibrated Isochrones | |
| dc.type | text |