A Hipparcos study of the Hyades open cluster. Improved colour-absolute magnitude and Hertzsprung-Russell diagrams

By J. Bruijne, R. Hoogerwerf, P. de Zeeuw. 2000

145 citations recorded by the source corpus.

Hipparcos parallaxes x distances to individual stars in the Hyades cluster with an accuracy of 6p er- cent. We use the Hipparcos proper motions, which have a larger relative precision than the trigonometric paral- laxes, to derive 3 times more precise distance estimates, by assuming that all members share the same space motion. An investigation of the available kinematic data conrms that the Hyades velocity eld does not contain signicant structure in the form of rotation and/or shear, but is fully consistent with a common space motion plus a (one-dimensional) internal velocity dispersion of 0.30 km s 1 . The improved parallaxes as a set are statistically consistent with the Hipparcos parallaxes. The maximum expected systematic error in the proper motion-based parallaxes for stars in the outer regions of the cluster (i.e., beyond 2 tidal radii 20 pc) is < 0.30 mas. The new parallaxes conrm that the Hipparcos measurements are correlated on small angular scales, consistent with the limits specied in the Hipparcos Catalogue, though with signicantly smaller \amplitudes" than claimed by Narayanan & Gould. We use the Tycho{2 long time-baseline astrometric catalogue to derive a set of independent proper motion-based parallaxes for the Hipparcos members. The new parallaxes provide a uniquely sharp view of the three-dimensional structure of the Hyades. The colour-absolute magnitude diagram of the cluster based on the new parallaxes shows a well-dened main sequence with two \gaps"/\turn-os". These features provide the rst direct observational support of Bohm{Vitense's prediction that (the onset of) surface convection in stars signicantly aects their (B V ) colours. We present and discuss the theoretical Hertzsprung{Russell diagram (log L versus log Te) for an objectively dened set of 88 high-delity members of the cluster as well as the Scuti star 2 Tau, the giants 1 , 1 , ,a nd Tau, and the white dwarfs V471 Tau and HD 27483 (all of which are also members). The precision with which the new parallaxes place individual Hyades in the Hertzsprung{Russell diagram is limited by (systematic) uncertainties related to the transformations from observed colours and abso- lute magnitudes to eective temperatures and luminosities. The new parallaxes provide stringent constraints on the calibration of such transformations when combined with detailed theoretical stellar evolutionary modelling, tailored to the chemical composition and age of the Hyades, over the large stellar mass range of the cluster probed by Hipparcos.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/9ad120c9f9bda1ee650db7346c3b8cea013cf968

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Instrumentation

Citations in the corpus

A Planetary Companion to the Hyades Giant ϵ Tauri (2007, background): “527 Tau (HR 1409, HD 28305, HIP 20889) is one of the highfidelity members of the cluster based on parallax, proper motion, and radial velocity (Perryman et al. 1998; de Bruijne et al. 2001).”
A REVISED AGE FOR UPPER SCORPIUS AND THE STAR FORMATION HISTORY AMONG THE F-TYPE MEMBERS OF THE SCORPIUS–CENTAURUS OB ASSOCIATION (2011, background): “Kinematically improved parallaxes have been shown to reduce scatter in the H-R diagram (see the Hyades in de Bruijne et al. (2001) for a good example) and a comparison with trigonometric parallaxes can further help identify interlopers.”
Searching for Planets in the Hyades. IV. Differential Abundance Analysis of Hyades Dwarfs (2003, background): “…photometry, radial velocity and Hipparcos distances for membership. vB 1 has a slightly low activity level as compared to the cluster mean. de Bruijne et al. (2001) find that these stars are nonmembers based on the proper motion and trigonometric parallax analyses of both de Bruijne (1999)…”
The Dartmouth Stellar Evolution Database (2008, background): “I (center) CMDs of the Hyades (de Bruijne et al. 2001) and the combined Hipparcos and 2MASS V–Ks CMD compiled by Pinsonneault et al. (2004).”
Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics (2008, methodology): “The moving cluster distances and probabilities were calculated following Mamajek (2005) using the de Bruijne et al. (2001) convergent point solution with Hipparcos, Tycho-2, or UCAC2 proper motions (in order of preference).”
The White Dwarf Initial–Final Mass Relation for Progenitor Stars from 0.85 to 7.5 M⊙ (2018, methodology): “For this current analysis a higher precision in photometric age analysis is necessary, and we have adopted the secular parallaxes for individual Hyades members calculated in de Bruijne et al. (2001).”
Gaia Data Release 2 (2018, background): “Similarly, proper motions contain distance information which can be used to good effect to derive more precise distances or luminosities for open cluster members (e.g. de Bruijne et al. 2001; Gaia Collaboration 2017b).”
Parallaxes and proper motions for 20 open clusters as based on the new Hipparcos catalogue (2009, methodology): “A major study of the Hyades cluster as based on the first Hipparcos catalogue was presented by Perryman et al. (1998), and further studies based on the same data by Madsen et al. (2000), Madsen et al. (2001) and de Bruijne et al. (2001).”