Untitled

Kharchenko, N. K.; Synytsky, V. N.; Koval, Z

doi:10.1023/a:1023039003169

Cited by 3 publications

(3 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In our Further study of the bottom (U ; V )-and (W ; V )-planes of Figure 6 reveals that about 40% of the L and T dwarfs lie near the Hyades moving group either within the 2 ellipsoid or ''touching'' it (i.e., the error bars cross the 2 ellipsoid). To analyze the significance of such an apparent concentration, we have collected accurate radial velocities and Hipparcos distances and parallaxes of F-, G-, K-, and M-type stars within 20 pc of the Sun from the catalog of Kharchenko (2004). A total of 10 F stars, 25 solar-type stars, 58 K, and 52 early M ( M0YM5) stars were selected.…”

Section: Star Moving Groupsmentioning

confidence: 99%

“…References.-Radial velocities: (1) Kharchenko (2004); (2) and references therein) that we can use to estimate the mean age for our kinematic samples. According to the -age relations provided in Tables 2 (A and F stars) and 3 (GYKYM stars) by Mayor (1974), the mean age of the 20 pc sample of F stars is about 2 Gyr and that of the G to early M stars is about 5 Gyr (i.e., the age of the Sun).…”

Section: Galactic Kinematics and Age Of The Ultracool Dwarfsmentioning

confidence: 99%

“…References. -Radial velocities from (1) Kharchenko (2004); (2) this paper; (3) Mohanty & Basri (2003); (4) Bailer-Jones (2004). Distances and proper motions from (5) Perryman et al (1997); (6) Dahn et al (2002); (7) Vrba et al (2004); (8) Reid et al (2002).…”

Section: -7mentioning

confidence: 99%

See 2 more Smart Citations

Space Velocities of L‐ and T‐Type Dwarfs

Osorio

Martín

Béjar

et al. 2007

ApJ

View full text Add to dashboard Cite

We have obtained radial velocities of a sample of 18 ultracool dwarfs (M6.5YT8) using high-resolution, nearinfrared spectra obtained with NIRSPEC and the Keck II telescope. We have confirmed that the radial velocity of Gl 570D is coincident with that of the K-type primary star Gl 570A, thus providing additional support for their true companionship. The presence of planetary-mass companions around 2MASS J05591914À1404488 (T4.5 V ) has been analyzed using five NIRSPEC radial velocity measurements obtained over a period of 4.37 yr. We have computed UVW space motions for a total of 21 L and T dwarfs within 20 pc of the Sun. This population shows UVW velocities that nicely overlap the typical kinematics of solar to M-type stars within the same spatial volume. However, the mean Galactic and tangential velocities of the L and T dwarfs appear to be smaller than those of G to M stars. A significant fraction ($40%) of the ultracool dwarfs lie near the Hyades moving group (0.4Y2 Gyr), which contrasts with the 10%Y12% found for earlier type stellar neighbors. In addition, the distributions of the UVW components and the distributions of the total Galactic and tangential velocities derived for the L and T sample are narrower than those measured for nearby G-, K-, and M-type stars, but similar to the dispersions obtained for F stars. This suggests that, in the solar neighborhood, the population of L-and T-type ultracool dwarfs (including brown dwarfs) is kinematically younger than solar-type to early M stars, with likely ages in the interval 0.5Y4 Gyr.

show abstract

Section: Star Moving Groupsmentioning

confidence: 99%

Section: Galactic Kinematics and Age Of The Ultracool Dwarfsmentioning

confidence: 99%