SOUNDING OPEN CLUSTERS: ASTEROSEISMIC CONSTRAINTS FROM KEPLER ON THE PROPERTIES OF NGC 6791 AND NGC 6819
- Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States)
- Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C (Denmark)
- Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW 2006 (Australia)
- Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada)
- School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)
- LESIA, CNRS, Universite Pierre et Marie Curie, Universite Denis Diderot, Observatoire de Paris, 92195 Meudon (France)
- Laboratoire AIM, CEA/DSM-CNRS, Universite Paris 7 Diderot, IRFU/SAp, Centre de Saclay, 91191 Gif-sur-Yvette (France)
- High Altitude Observatory, National Center for Atmospheric Research, Boulder, CO 80307 (United States)
- Department of Astronomy, Beijing Normal University, Beijing 100875 (China)
- Laboratoire d'Astrophysique de Toulouse-Tarbes, Universite de Toulouse, CNRS, 31400 Toulouse (France)
- Institute for Computational Astrophysics, Department of Astronomy and Physics, Saint Marys University, Halifax, NS B3H 3C3 (Canada)
- Institut d'Astrophysique et Geophysique de l'Universite de Liege, Allee du six Aout, 17 B-4000 Liege (Belgium)
- Department of Astronomy and Space Sciences, Ege University, Bornova, 35100 Izmir (Turkey)
We present initial results on some of the properties of open clusters NGC 6791 and NGC 6819 derived from asteroseismic data obtained by NASA's Kepler mission. In addition to estimating the mass, radius, and log g of stars on the red giant branch (RGB) of these clusters, we estimate the distance to the clusters and their ages. Our model-independent estimate of the distance modulus of NGC 6791 is (m - M){sub 0} = 13.11 {+-} 0.06. We find (m - M){sub 0} = 11.85 {+-} 0.05 for NGC 6819. The average mass of stars on the RGB of NGC 6791 is 1.20 {+-} 0.01 M{sub sun}, while that of NGC 6819 is 1.68 {+-} 0.03 M{sub sun}. It should be noted that we do not have data that cover the entire RGB and the actual mass will be somewhat lower. We have determined model-dependent estimates of ages of these clusters. We find ages between 6.8 and 8.6 Gyr for NGC 6791, however, most sets of models give ages around 7 Gyr. We obtain ages between 2 and 2.4 Gyr for NGC 6819.
- OSTI ID:
- 21560465
- Journal Information:
- Astrophysical Journal Letters, Vol. 729, Issue 1; Other Information: DOI: 10.1088/2041-8205/729/1/L10; ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
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