Hostname: page-component-78c5997874-8bhkd Total loading time: 0 Render date: 2024-11-13T13:23:01.634Z Has data issue: false hasContentIssue false
  • English
  • Français

Rotational and Candidate-Eclipsing-Binary Light Curves for Pre-Main-Sequence Stars in the Chamaeleon I Star-Forming Cloud

Published online by Cambridge University Press:  05 March 2013

Warrick A. Lawson  and
Lisa A. Crause
Warrick A. Lawson*
Affiliation:
School of Physical, Enviromental & Mathematical Sciences, University of New South Wales, Australian Defence Force Academy, Canberra, ACT 2600, Australia
Lisa A. Crause
Affiliation:
South African Astronomical Observatory, P.O. Box 9, Observatory 7935, South Africa
*
CCorresponding author. Email: w.lawson@adfa.edu.au
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We present the results of a photometric survey for variability in ten X-ray-emitting low-mass stars in the Chamaeleon region. Eight of the stars we observed are bona fide pre-main-sequence members of the ∼2 Myr-old Chamaeleon I star-forming cloud. The other two stars are young with high levels of relative X-ray emission, but with discordant proper motions they are probable non-members of the cloud. In six of the stars we monitored, periodic variations on timescales of 2.5–11.5 d were detected, that we ascribe to stellar rotation and the presence of cool starspots. Two other stars, CHXR 20 and CHXR 85, show large amplitude variations at visual and near-infrared wavelengths and are candidate eclipsing binaries. Compared to the rotational properties of low-mass stars in the ≈8 Myr-old η Chamaeleontis cluster, we find that the older η Chamaeleontis stars have several times higher surface specific angular momentum than the younger Chamaeleon I stars. The apparent increase in angular momentum between ∼2 and 8 Myr might be due to changes in stellar internal structure as the stars evolve, or evidence for a different rotational history between members of the two star-forming regions.

Keywords

open clusters and associations: individual (Chamaeleon I)stars: individual (CHXR 3, CHXR 20, CHXR 33, CHXR 37, CHXR 40, CHXR 47, CHXR 53, CHXR 59, CHXR 71, CHXR 85)stars: pre-main sequencestars: rotationstars: spotsbinaries: eclipsing
Type
Research Article
Information
Publications of the Astronomical Society of Australia , Volume 26 , Issue 1 , 2009 , pp. 31 - 36
Copyright
Copyright © Astronomical Society of Australia 2009

References

Alcalá, J. M., Krautter, J., Schmitt, J. H. M. M., Covino, E., Wichmann, R. & Mundt, R., 1995, A&AS, 114, 109 Google Scholar
Allain, S., Bouvier, J., Prosser, C., Marscall, L. A. & Laaksonen, B. D., 1996, A&A, 305, 498 Google Scholar
Baraffe, I., Chabrier, G., Allard, F. & Hauschildt, P. H., 1998, A&A, 337, 403 Google Scholar
Bouvier, J., Bertout, C., Benz, W. & Mayor, M., 1986, A&A, 165, 110 Google Scholar
Bouwman, J., Lawson, W. A., Dominik, C., Feigelson, E. D., Henning, T., Tielens, A. G. G. G. & Waters, L. B. F. F., 2006, ApJ, 653, L57 Google Scholar
Carpenter, J. M., Hillenbrand, L. A., Skrutskie, M. F. & Meyer, M. R., 2002, AJ, 124, 1001 Google Scholar
Chabrier, G., Baraffe, I., Allard, F. & Hauschildt, P. H., 2001, A&A, 380, 609 Google Scholar
Damjanov, I., Jayawardhana, R., Scholz, A., Nguyen, D. C., Brandeker, A. & van Kerkwijk, M. H., 2007, ApJ, 670, 1337 Google Scholar
Feigelson, E. D., Casanova, S., Montmerle, T. & Guibert, J., 1993, ApJ, 416, 623 Google Scholar
Franchini, M., Magazzú, A. & Stalio, R., 1988, A&A, 189, 132 Google Scholar
Huenemoerder, D. P., Lawson, W. A. & Feigelson, E. D., 1994, MNRAS, 271, 967 CrossRefGoogle Scholar
Jayawardhana, R., Mohanty, S. & Basri, G., 2003, ApJ, 592, 282 Google Scholar
Joergens, V., Fernández, M., Carpenter, J. M. & Neuhäuser, R., 2003, ApJ, 594, 971 Google Scholar
Lawson, W. A., Feigelson, E. D. & Huenemoerder, D. P., 1996, MNRAS, 280, 1071 Google Scholar
Lawson, W. A., Crause, L. A., Mamajek, E. E. & Feigelson, E. D., 2001, MNRAS, 321, 57 Google Scholar
Lawson, W. A., Crause, L. A., Mamajek, E. E. & Feigelson, E. D., 2002, MNRAS, 329, L29 Google Scholar
Luhman, K. L., 2004, ApJ, 602, 816 Google Scholar
Luhman, K. L. et al., 2008, ApJ, 675, 1375 Google Scholar
Monet, D. G. et al., 2003, AJ, 125, 984 CrossRefGoogle Scholar
Skelly, M. B., Unruh, Y. C., Collier Cameron, A., Barnes, J. R., Donati, J.-F., Lawson, W. A. & Carter, B. A., 2008, MNRAS, 385, 708 Google Scholar
Stassun, K. G., Mathieu, R. D. & Valenti, J. A., 2006, Nature, 440, 311 Google Scholar
Wichmann, R., Bouvier, J., Allain, S. & Krautter, J., 1998, A&A, 330, 521 Google Scholar
Zacharias, N., Urban, S. E., Zacharias, M. I., Wycoff, G. L., Hall, D. M., Germain, M. E., Holdenried, E. R. & Winter, L., 2004, AJ, 127, 3043 Google Scholar