Magnetic Activity of Pre-main Sequence Stars near the Stellar-Substellar Boundary
Abstract
X-ray observations of pre-main sequence (pre-MS) stars of M-type probe coronal emission and offer a means to investigate magnetic activity at the stellar-substellar boundary. Recent observations of main sequence (MS) stars at this boundary display a decrease in fractional X-ray luminosity (/) by almost two orders of magnitude for spectral types M7 and later. We investigate magnetic activity and search for a decrease in X-ray emission in the pre-MS progenitors of these MS stars. We present XMM-Newton X-ray observations and preliminary results for ~10 nearby (30-70 pc), very low mass pre-MS stars in the relatively unexplored age range of 10-30 Myr. We compare the fractional X-ray luminosities of these 10-30 Myr old stars to younger (1-3 Myr) pre-MS brown dwarfs and find no dependence on spectral type or age suggesting that X-ray activity declines at an age later than ~30 Myr in these very low-mass stars.
Keywords
Cite
@article{arxiv.1512.01240,
title = {Magnetic Activity of Pre-main Sequence Stars near the Stellar-Substellar Boundary},
author = {David A. Principe and Joel H. Kastner and David Rodriguez},
journal= {arXiv preprint arXiv:1512.01240},
year = {2016}
}
Comments
2 pages, 1 figure, to appear in "Young Stars and Planets Near the Sun", Proceedings of IAU Symposium No. 314 (Cambridge University Press), J.H. Kastner, B. Stelzer, S.A. Metchev, eds