Show simple item record

dc.creatorRobertson, Paulen_US
dc.creatorEndl, Michaelen_US
dc.creatorCochran, William D.en_US
dc.creatorDodson-Robinson, Sarah E.en_US
dc.date.accessioned2016-04-28T19:37:59Z
dc.date.available2016-04-28T19:37:59Z
dc.date.issued2013-02en
dc.identifierdoi:10.15781/T2KR66
dc.identifier.citationRobertson, Paul, Michael Endl, William D. Cochran, and Sarah E. Dodson-Robinson. "H? activity of old M dwarfs: Stellar cycles and mean activity levels for 93 low-mass stars in the solar neighborhood." The Astrophysical Journal, Vol. 764, No. 1 (Feb., 2013): 3.en_US
dc.identifier.issn0004-637Xen_US
dc.identifier.urihttp://hdl.handle.net/2152/34969
dc.description.abstractThrough the McDonald Observatory M Dwarf Planet Search, we have acquired nearly 3000 high-resolution spectra of 93 late-type (K5-M5) stars over more than a decade using the High Resolution Spectrograph on the Hobby-Eberly Telescope. This sample provides a unique opportunity to investigate the occurrence of long-term stellar activity cycles for low-mass stars. In this paper, we examine the stellar activity of our targets as reflected in the H alpha feature. We have identified periodic signals for six stars, with periods ranging from days to more than 10 years, and find long-term trends for seven others. Stellar cycles with P >= 1 year are present for at least 5% of our targets. Additionally, we present an analysis of the time-averaged activity levels of our sample, and search for correlations with other stellar properties. In particular, we find that more massive, earlier type (M0-M2) stars tend to be more active than later type dwarfs. Furthermore, high-metallicity stars tend to be more active at a given stellar mass. We also evaluate H alpha variability as a tracer of activity-induced radial velocity (RV) variation. For the M dwarf GJ 1170, H alpha variation reveals stellar activity patterns matching those seen in the RVs, mimicking the signal of a giant planet, and we find evidence that the previously identified stellar activity cycle of GJ 581 may be responsible for the recently retracted planet f in that system. In general, though, we find that H alpha is not frequently correlated with RV at the precision (typically 6-7 m s(-1)) of our measurements.en_US
dc.description.sponsorshipUniversity of Texas Continuing Fellowshipen_US
dc.description.sponsorshipNational Aeronautics and Space Administration NNX09AB30G, NNG04G141Gen_US
dc.language.isoEnglishen_US
dc.relation.ispartofen_US
dc.rightsAdministrative deposit of works to Texas ScholarWorks: This works author(s) is or was a University faculty member, student or staff member; this article is already available through open access or the publisher allows a PDF version of the article to be freely posted online. The library makes the deposit as a matter of fair use (for scholarly, educational, and research purposes), and to preserve the work and further secure public access to the works of the University.en_US
dc.subjectplanetary systemsen_US
dc.subjectstars: activityen_US
dc.subjectstars: kinematics and dynamicsen_US
dc.subjectstars: late-typeen_US
dc.subjecttechniques: radial velocitiesen_US
dc.subjecttechniques:en_US
dc.subjectspectroscopicen_US
dc.subjectdigital sky surveyen_US
dc.subjecthobby-eberly telescopeen_US
dc.subjectca-ii hen_US
dc.subjectmagnetic activityen_US
dc.subjectchromospheric activityen_US
dc.subjectmain-sequenceen_US
dc.subjectplanet searchen_US
dc.subjectphotometricen_US
dc.subjectcalibrationen_US
dc.subjecthabitable zoneen_US
dc.subjectharps searchen_US
dc.subjectastronomy & astrophysicsen_US
dc.titleH Alpha Activity Of Old M Dwarfs: Stellar Cycles And Mean Activity Levels For 93 Low-Mass Stars In The Solar Neighborhooden_US
dc.typeArticleen_US
dc.description.departmentAstronomyen_US
dc.identifier.Filename2013_02_halphaactivity.pdfen_US
dc.rights.restrictionOpenen_US
dc.identifier.doi10.1088/0004-637x/764/1/3en_US
dc.contributor.utaustinauthorRobertson, Paulen_US
dc.contributor.utaustinauthorEndl, Michaelen_US
dc.contributor.utaustinauthorCochran, William D.en_US
dc.contributor.utaustinauthorDodson-Robinson, Sarah E.en_US
dc.relation.ispartofserialAstrophysical Journalen_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record