We present the results of an age determination study for pre-main sequence stars in the Ophiuchus molecular cloud. The ages of eight pre-main sequence stars were estimated from surface gravities derived from high-resolution spectroscopy. The average age of the target stars was 0.7 Myr. By comparing the individual age and the near-infrared color excess, we found that color excess decreases gradually with a constant rate and the lifetime of the inner disk was determined to be 1.2 Myr. The estimated lifetime is nearly a half of the time compared to that of the pre-main sequence stars in the Taurus molecular cloud estimated with the same method. This result indicates that the disk evolution timescale depends on the environment of the star-forming region.
@article{arxiv.1506.04363,
title = {Rapid Dissipation of Protoplanetary Disks in Ophiuchus},
author = {Yuhei Takagi and Yoichi Itoh and Akira Arai and Sai Shoko and Yumiko Oasa},
journal= {arXiv preprint arXiv:1506.04363},
year = {2015}
}
Comments
12 pages, 3 figures, accepted for publication in Publications of the Astronomical Society of Japan