A FIRST LOOK AT ROTATION IN INACTIVE LATE-TYPE M DWARFS
We have examined the relationship between rotation and activity in 14 late-type (M6–M7) M dwarfs, using high-resolution spectra taken at the W. M. Keck Observatory and flux-calibrated spectra from the Sloan Digital Sky Survey. Most were selected to be inactive at a spectral type where strong Hα emis...
| Main Authors: | , |
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| Format: | Article |
| Language: | en_US |
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Institute of Physics/American Astronomical Society
2015
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| Online Access: | http://hdl.handle.net/1721.1/95911 |
| _version_ | 1811094030228914176 |
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| author | Basri, Gibor West, A. A. |
| author2 | MIT Kavli Institute for Astrophysics and Space Research |
| author_facet | MIT Kavli Institute for Astrophysics and Space Research Basri, Gibor West, A. A. |
| author_sort | Basri, Gibor |
| collection | MIT |
| description | We have examined the relationship between rotation and activity in 14 late-type (M6–M7) M dwarfs, using high-resolution spectra taken at the W. M. Keck Observatory and flux-calibrated spectra from the Sloan Digital Sky Survey. Most were selected to be inactive at a spectral type where strong Hα emission is quite common. We used the cross-correlation technique to quantify the rotational broadening; six of the stars in our sample have v sin i ≥ 3.5 km s[superscript –1]. Our most significant and perplexing result is that three of these stars do not exhibit Hα emission, despite rotating at velocities where previous work has observed strong levels of magnetic field and stellar activity. Our results suggest that rotation and activity in late-type M dwarfs may not always be linked, and open several additional possibilities, including a rotationally dependent activity threshold, or a possible dependence on stellar parameters of the Rossby number at which magnetic/activity "saturation" takes place in fully convective stars. |
| first_indexed | 2024-09-23T15:54:23Z |
| format | Article |
| id | mit-1721.1/95911 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T15:54:23Z |
| publishDate | 2015 |
| publisher | Institute of Physics/American Astronomical Society |
| record_format | dspace |
| spelling | mit-1721.1/959112022-09-29T16:57:01Z A FIRST LOOK AT ROTATION IN INACTIVE LATE-TYPE M DWARFS Basri, Gibor West, A. A. MIT Kavli Institute for Astrophysics and Space Research West, Andrew A. We have examined the relationship between rotation and activity in 14 late-type (M6–M7) M dwarfs, using high-resolution spectra taken at the W. M. Keck Observatory and flux-calibrated spectra from the Sloan Digital Sky Survey. Most were selected to be inactive at a spectral type where strong Hα emission is quite common. We used the cross-correlation technique to quantify the rotational broadening; six of the stars in our sample have v sin i ≥ 3.5 km s[superscript –1]. Our most significant and perplexing result is that three of these stars do not exhibit Hα emission, despite rotating at velocities where previous work has observed strong levels of magnetic field and stellar activity. Our results suggest that rotation and activity in late-type M dwarfs may not always be linked, and open several additional possibilities, including a rotationally dependent activity threshold, or a possible dependence on stellar parameters of the Rossby number at which magnetic/activity "saturation" takes place in fully convective stars. National Science Foundation (U.S.) (NSF grant AST- 0606748) W. M. Keck Foundation Alfred P. Sloan Foundation United States. Dept. of Energy 2015-03-06T19:40:31Z 2015-03-06T19:40:31Z 2009-03 2008-10 Article http://purl.org/eprint/type/JournalArticle 0004-637X 1538-4357 http://hdl.handle.net/1721.1/95911 West, Andrew A., and Gibor Basri. “A FIRST LOOK AT ROTATION IN INACTIVE LATE-TYPE M DWARFS.” The Astrophysical Journal 693, no. 2 (March 9, 2009): 1283–1289. © 2009 American Astronomical Society. en_US http://dx.doi.org/10.1088/0004-637x/693/2/1283 Astrophysical Journal Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf Institute of Physics/American Astronomical Society American Astronomical Society |
| spellingShingle | Basri, Gibor West, A. A. A FIRST LOOK AT ROTATION IN INACTIVE LATE-TYPE M DWARFS |
| title | A FIRST LOOK AT ROTATION IN INACTIVE LATE-TYPE M DWARFS |
| title_full | A FIRST LOOK AT ROTATION IN INACTIVE LATE-TYPE M DWARFS |
| title_fullStr | A FIRST LOOK AT ROTATION IN INACTIVE LATE-TYPE M DWARFS |
| title_full_unstemmed | A FIRST LOOK AT ROTATION IN INACTIVE LATE-TYPE M DWARFS |
| title_short | A FIRST LOOK AT ROTATION IN INACTIVE LATE-TYPE M DWARFS |
| title_sort | first look at rotation in inactive late type m dwarfs |
| url | http://hdl.handle.net/1721.1/95911 |
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