Search Publications
The Cepheid period-luminosity zero-point from HIPPARCOS trigonometrical parallaxes
Catchpole, R. M.; Feast, M. W.
Hipparcos trigonometrical parallaxes of Cepheid variables are used to derive a zero-point for the period-luminosity (PL) relation. Adopting a slope from the Large Magellanic Cloud (LMC), the relation is found to be <M_V>=-2.81 log P-1.43. The standard error of the zero-point is 0.10 mag. Together with metallicity corrections this corresponds…
Galactic kinematics of Cepheids from HIPPARCOS proper motions
Feast, Michael; Whitelock, Patricia
The Hipparcos proper motions of 220 Galactic Cepheids, together with relevant ground-based photometry, have been analysed. The effects of Galactic rotation are very clearly seen. Mean values of the Oort constants, A=14.82+/-0.84 km s^-1 kpc^-1, and B=-12.37+/-0.64 km s^-1 kpc^-1, and of the angular velocity of circular rotation at the Sun, Omega_o…
First results from HIPPARCOS trigonometrical parallaxes of Mira-type variables
van Leeuwen, F.; Whitelock, P. A.; Feast, M. W. +1 more
HIPPARCOS trigonometrical parallaxes are given for 16 pre-selected Mira variables. Linear diameters are derived for eight oxygen-rich Miras with known angular diameters. Comparison with pulsation theory shows that two of them (both with periods over 400d) are fundamental pulsators, while the others (all with periods of less than 400d) pulsate in a…
Kinematic ages of OB associations
Brown, A. G. A.; de Zeeuw, P. T.; Dekker, G.
Astrometric data from the HIPPARCOS mission include measurements of early-type stars in nearly all OB associations within 1kpc from the Sun, and are available as of 1996. In anticipation thereof we studied the determination of kinematic ages and initial sizes of OB associations. These studies have traditionally been done using proper motion data. …
The mass, temperature and distance of the white dwarf in V471 Tauri
Barstow, M. A.; Holberg, J. B.; Cruise, A. M. +1 more
We present an analysis of far-UV observations of V471 Tauri made during the first ORFEUS mission. Combining this spectrum with archival data from IUE allows a first unambiguous measurement of the effective temperature and surface gravity of the white dwarf by matching the observed Lyman line profiles to the predictions of stellar model atmosphere …