Search Publications
AGB variables and the Mira period-luminosity relation
Whitelock, Patricia A.; Feast, Michael W.; Van Leeuwen, Floor
Published data for large-amplitude asymptotic giant branch variables in the Large Magellanic Cloud (LMC) are re-analysed to establish the constants for an infrared (K) period-luminosity relation of the form MK=ρ[log P- 2.38]+δ. A slope of ρ=-3.51 ± 0.20 and a zero-point of δ=-7.15 ± 0.06 are found for oxygen-rich Miras (if a distance mo…
The Radial Velocity Experiment (RAVE): Second Data Release
Gilmore, G.; Freeman, K. C.; Evans, N. W. +51 more
We present the second data release of the Radial Velocity Experiment (RAVE), an ambitious spectroscopic survey to measure radial velocities and stellar atmosphere parameters (temperature, metallicity, surface gravity, and rotational velocity) of up to one million stars using the 6 dF multi-object spectrograph on the 1.2 m UK Schmidt Telescope of t…
Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity
Latham, David W.; Stefanik, Robert P.; Massarotti, Alessandro +1 more
We present rotational and radial velocities for a sample of 761 giants selected from the Hipparcos Catalogue to lie within 100 pc of the Sun. Our original goal was to examine stellar rotation in field giants using spectroscopic line broadening to look for evidence of excess rotation that could be attributed to planets that were engulfed as the par…
M dwarfs: effective temperatures, radii and metallicities
Casagrande, Luca; Flynn, Chris; Bessell, Michael
We empirically determine effective temperatures and bolometric luminosities for a large sample of nearby M dwarfs, for which high accuracy optical and infrared photometry is available. We introduce a new technique which exploits the flux ratio in different bands as a proxy of both effective temperature and metallicity. Our temperature scale for la…
A catalogue of multiplicity among bright stellar systems
Eggleton, P. P.; Tokovinin, A. A.
We consider the multiplicity of stellar systems with (combined) magnitude brighter than 6.00 in Hipparcos magnitudes. We identify 4559 such bright systems (including the Sun), and the frequencies of multiplicities 1, 2,..., 7 are found to be 2718, 1437, 285, 86, 20, 11 and 2. We discuss the uncertainties, which are substantial. We also consider th…
PPM-Extended (PPMX) - a catalogue of positions and proper motions
Schwan, H.; Scholz, R. -D.; Piskunov, A. E. +3 more
Aims: We build a catalogue PPM-Extended (PPMX) on the ICRS system which is complete down to a well-defined limiting magnitude and contains the best presently available proper motions suited for kinematic studies in the Galaxy.
Methods: We perform a rigorous weighted least-squares adjustment of individual observations, spread over more than a c…
Eclipsing Binary Solutions in Physical Units and Direct Distance Estimation
Wilson, R. E.
Opportunities for extraction of distances and temperatures from eclipsing binary light curves that are in standard flux units, as opposed to traditional arbitrary units, are examined. Benefits include (1) distance becomes an ordinary solution parameter with a standard error, (2) temperatures of both stars may be derivable in favorable circumstance…
Hipparcos distance estimates of the Ophiuchus and the Lupus cloud complexes
Alves, J.; Lombardi, M.; Lada, C. J.
We combine extinction maps from the Two Micron All Sky Survey (2MASS) with Hipparcos and Tycho parallaxes to obtain reliable and high-precision estimates of the distance to the Ophiuchus and Lupus dark complexes. Our analysis, based on a rigorous maximum-likelihood approach, shows that the ρ-Ophiuchi cloud is located at (119 ± 6) pc and the Lupus …
The luminosities and distance scales of type II Cepheid and RR Lyrae variables
van Leeuwen, Floor; Whitelock, Patricia A.; Feast, Michael W. +2 more
Infrared and optical absolute magnitudes are derived for the type II Cepheids κ Pav and VY Pyx using revised Hipparcos parallaxes and for κ Pav, V553 Cen and SW Tau from pulsational parallaxes. Revised Hipparcos and HST parallaxes for RR Lyrae agree satisfactorily and are combined in deriving absolute magnitudes. Phase-corrected J, H and Ks
On the distance to the Ophiuchus star-forming region
Mamajek, E. E.
The Ophiuchus molecular cloud complex has produced in Lynds 1688 the richest known embedded cluster within ∼300 pc of the Sun. Unfortunately, distance estimates to the Oph complex vary by nearly ∼40% (∼120-165 pc). Here I calculate a new independent distance estimate of 135 ± 8 pc to this benchmark star-forming region based on Hipparcos trigonomet…