J/ApJ/704/975 Rotational velocities for M dwarfs (Jenkins+, 2009)
Rotational velocities for M dwarfs.
Jenkins J.S., Ramsey L.W., Jones H.R.A., Pavlenko Y., Gallardo J.,
Barnes J.R., Pinfield D.J.
<Astrophys. J., 704, 975-988 (2009)>
=2009ApJ...704..975J 2009ApJ...704..975J
ADC_Keywords: Stars, dwarfs ; Stars, M-type ; Rotational velocities
Keywords: planetary systems - stars: fundamental parameters - stars:low-mass,
brown dwarfs - stars: rotation
Abstract:
We present spectroscopic rotation velocities (vsini) for 56 M dwarf
stars using high-resolution Hobby-Eberly Telescope High Resolution
Spectrograph red spectroscopy. In addition, we have also determined
photometric effective temperatures, masses, and metallicities ([Fe/H])
for some stars observed here and in the literature where we could
acquire accurate parallax measurements and relevant photometry. We
have increased the number of known vsini values for mid M stars by
around 80% and can confirm a weakly increasing rotation velocity with
decreasing effective temperature. Our sample of vsini is peak at low
velocities (∼3km/s). We find a change in the rotational velocity
distribution between early M and late M stars, which is likely due to
the changing field topology between partially and fully convective
stars. There is also a possible further change in the rotational
distribution toward the late M dwarfs where dust begins to play a role
in the stellar atmospheres. We also link vsini to age and show how it
can be used to provide mid-M star age limits. When all literature
velocities for M dwarfs are added to our sample, there are 198 with
vsini≤10km/s and 124 in the mid-to-late M star regime (M3.0-M9.5)
where measuring precision optical radial velocities is difficult. In
addition, we also search the spectra for any significant Half emission
or absorption. Forty three percent were found to exhibit such emission
and could represent young, active objects with high levels of
radial-velocity noise. We acquired two epochs of spectra for the star
GJ1253 spread by almost one month and the Half profile changed from
showing no clear signs of emission, to exhibiting a clear emission
peak. Four stars in our sample appear to be low-mass binaries (GJ1080,
GJ3129, Gl802, and LHS3080), with both GJ3129 and Gl802 exhibiting
double Half emission features. The tables presented here will aid any
future M star planet search target selection to extract stars with low
vsini.
Description:
Rotational velocities are presented for a sample of 56 M dwarf stars
that were observed with the HRS instrument on the 10m Hobby-Eberly
Telescope. The star designation along with optical and near infrared
colours, spectral types, effective temperatures, parallaxes, masses,
metallicities and the rotational velocities are listed. In addition,
the FWHM of the telluric absorption lines are listed as a proxy for
the instrumental profile of HRS and if any H-α line emission was
present this has been flagged also. Four binary M dwarfs have been
listed, along with the individual rotational velocities found for each
component. Literature rotational velocities are also included with the
same information and including the source of the rotational velocity
measurement.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 101 49 Spectral types, basic physical parameters, and
chromospheric indices
table2.dat 79 4 Stars beyond 40 parsecs identified by MK
classification
table3.dat 101 199 Candidate stars for terrestrial planet surveys
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See also:
III/226 : Rotational Velocities of Stars (Glebocki+ 2000)
J/A+A/331/581 : Rotation and activity in field M dwarfs (Delfosse+ 1998)
J/AJ/123/3356 : Palomar/MSU nearby star spec. survey. III. (Gizis+, 2002)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Star Star designation
9 A1 --- n_Star [*] Possible binary (1)
12- 16 F5.2 mag Vmag ?=- V magnitude
18- 22 F5.2 mag Jmag 2MASS J magnitude
24- 28 F5.2 mag Hmag 2MASS H magnitude
30- 34 F5.2 mag Ksmag 2MASS Ks magnitude
36- 39 A4 --- SpT M spectral type
41- 44 I4 K Teff Effective temperature
45- 46 A2 --- u_Teff [* ] Low accuracy on Teff (2)
48- 52 F5.1 mas plx ?=- Parallax
53 A1 --- --- [0]
55- 58 F4.1 mas e_plx ?=- rms uncertainty on plx
59 A1 --- --- [0]
61- 65 F5.3 Msun Mass ?=- Mass in solar masses
67- 71 F5.3 Msun e_Mass ?=- rms uncertainty on Mass
73- 77 F5.2 [Sun] [Fe/H] ?=- Metallicity
80- 81 A2 --- l_vsini [≤ ] Limit flag on vsini
82- 85 F4.1 km/s vsini Rotational velocity
87- 89 F3.1 km/s e_vsini ? rms uncertainty on vsini
91- 94 F4.1 km/s W(tell) Mean width (FWHM) of the telluric lines
96-101 A6 --- HaEm? [Yes/No ] Is Hα emission present?
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Note (1): * indicates weak evidence for a binary in the deconvolution or a
low S/N star that could affect the rotational velocity measurement.
Note (2): A double asterisk is used to flag highly suspect values.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Star Star designation
10- 14 F5.2 mag Vmag ?=- V magnitude (Hipparcos)
16- 19 F4.2 mag Jmag 2MASS J magnitude
21- 24 F4.2 mag Hmag 2MASS H magnitude
26- 29 F4.2 mag Ksmag 2MASS Ks magnitude
31- 34 A4 --- SpT M spectral type
36- 41 F6.2 km/s dV Velocity separation (1)
43- 46 F4.2 km/s e_dV rms uncertainty on deltaV
48- 49 A2 --- l_vsini1 [≤ ] Limit flag on vsini1
50- 52 F3.1 km/s vsini1 Rotational velocity of primary
54- 56 F3.1 km/s e_vsini1 ? rms uncertainty on vsini1
58- 59 A2 --- l_vsini2 [≤ ] Limit flag on vsini2
60- 62 F3.1 km/s vsini2 Rotational velocity of secondary
64- 66 F3.1 km/s e_vsini2 ? rms uncertainty on vsini2
68- 79 A12 --- HaEm? Is H-α emission present? (2)
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Note (1): The separation in velocity of the two deconvolved peaks.
Note (2): Information is given if there is a clear double H-α
emission peak, or if there is only a single emission peak.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 22 A22 --- Star Catalogue designation
24- 28 F5.2 mag Vmag ?=- V magnitude (Hipparcos)
30- 34 F5.2 mag Jmag ?=- 2MASS J magnitude
36- 40 F5.2 mag Hmag ? 2MASS H magnitude
42- 46 F5.2 mag Ksmag ? 2MASS Ks magnitude
48- 52 A5 --- SpT M spectral type
54- 57 I4 K Teff ?=- Effective temperature
59- 63 F5.1 mas plx ?=- Parallax
64 A1 --- --- [0]
66- 69 F4.1 mas e_plx ?=- rms uncertainty on plx
70 A1 --- --- [0]
72- 76 F5.3 Msun Mass ?=- Estimated stellar mass
78- 82 F5.3 Msun e_Mass ?=- rms uncertainty on Mass
84- 88 F5.2 [Sun] [Fe/H] ?=- Metallicity
90- 91 A2 --- l_vsini [≤ ] Limit flag on vsini
92- 95 F4.1 km/s vsini Rotational velocity
97- 99 F3.1 km/s e_vsini ? rms uncertainty on vsini
101 A1 --- r_vsini Source of rotational velocity (1)
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Note (1): References as follows:
a = Stauffer & Hartmann (1986ApJS...61..531S 1986ApJS...61..531S)
b = Marcy & Chen (1992ApJ...390..550M 1992ApJ...390..550M)
c = Delfosse et al. (1998, Cat. J/A+A/331/581)
d = Glebocki & Stawikowski (2000AcA....50..509G 2000AcA....50..509G, Cat. III/226)
e = Gizis et al. (2002, Cat. J/AJ/123/3356)
f = Mohanty & Basri (2003ApJ...583..451M 2003ApJ...583..451M)
g = Bailer-Jones (2004A&A...419..703B 2004A&A...419..703B)
h = Fuhrmeister & Schmitt (2004A&A...420.1079F 2004A&A...420.1079F)
i = Jones et al. (2005MNRAS.358..105J 2005MNRAS.358..105J)
j = Reiners (2007A&A...467..259R 2007A&A...467..259R)
k = West & Basri (2009ApJ...693.1283W 2009ApJ...693.1283W)
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Acknowledgements:
James Jenkins, jjenkins(at)das.uchile.cl
(End) Patricia Vannier [CDS] 11-Jan-2011