The kinematics of main-sequence stars from Hipparcos data

Conference item

We analyze a kinematically unbiased sample of 5610 stars around the south celestial pole that (i) have MK spectral types in the Michigan catalogues with luminosity class V and (ii) had photometric parallaxes that placed them within 80 pc of the Sun. We bin the stars by B - V and determine for each bin the solar motion from proper motions alone. As expected, the U and W components of the derived solar motions do not vary significantly from bin to bin, while the V component varies systematically. As the classic Stromberg relation predicts, V is a linear function of the variance S-2 within each bin around the solar motion. Extrapolating V (S-2) to S = 0 we determine the solar motion with respect to the LSR, obtaining a significantly smaller value of V than is usually employed. Parenago's discontinuity in the dependence of S-2 on spectral type emerges with exceptional clarity.

Authors: Binney, J; Dehnen, W; Houk, N; Murray, C; Penston, M

• Publication status: Published
• Journal: HIPPARCOS VENICE '97
• Volume: 402
• Pages: 473-477
• Publication date: 1997-01-01
• Event title: Hipparcos Venice 97
• ISSN: 0379-6566
• ISBN: 9290922915
• Keywords: stars; main-sequence; solar motion; Galactic structure