Search Publications
A new catalogue of Strömgren-Crawford uvbyβ photometry
Paunzen, E.
Context. The uvbyβ photometric system is widely used for the study of various Galactic and extragalactic objects. It measures the colour due to temperature differences, the Balmer discontinuity, and blanketing absorption due to metals.
Aims: A new all-sky catalogue of all available uvbyβ measurements from the literature was generated.
Me…
The Seven Sisters DANCe. I. Empirical isochrones, luminosity, and mass functions of the Pleiades cluster
Bertin, E.; Bouy, H.; Sarro, L. M. +7 more
Context. The DANCe survey provides photometric and astrometric (position and proper motion) measurements for approximately 2 million unique sources in a region encompassing ~80 deg2 centered on the Pleiades cluster.
Aims: We aim at deriving a complete census of the Pleiades and measure the mass and luminosity functions of the clust…
Cosmography of OB stars in the solar neighbourhood
Bouy, H.; Alves, J.
We construct a 3D map of the spatial density of OB stars within 500 pc from the Sun using the Hipparcos catalogue and find three large-scale stream-like structures that allow a new view on the solar neighbourhood. The spatial coherence of these blue streams and the monotonic age sequence over hundreds of parsecs suggest that they are made of young…
A survey of stellar X-ray flares from the XMM-Newton serendipitous source catalogue: HIPPARCOS-Tycho cool stars
Rosen, S.; Pye, J. P.; Schröder, A. C. +1 more
Context. The X-ray emission from flares on cool (i.e. spectral-type F-M) stars is indicative of very energetic, transient phenomena, associated with energy release via magnetic reconnection.
Aims: We present a uniform, large-scale survey of X-ray flare emission. The XMM-Newton Serendipitous Source Catalogue and its associated data products pr…
Long-lived, long-period radial velocity variations in Aldebaran: A planetary companion and stellar activity
Guenther, E. W.; Zechmeister, M.; Hatzes, A. P. +14 more
Aims: We investigate the nature of the long-period radial velocity variations in α Tau first reported over 20 yr ago.
Methods: We analyzed precise stellar radial velocity measurements for α Tau spanning over 30 yr. An examination of the Hα and Ca II λ8662 spectral lines, and Hipparcos photometry was also done to help discern the nature o…
Close encounters of the stellar kind
Bailer-Jones, C. A. L.
Stars which pass close to the Sun can perturb the Oort cloud, injecting comets into the inner solar system where they may collide with the Earth. Using van Leeuwen's re-reduction of the Hipparcos data complemented by the original Hipparcos and Tycho-2 catalogues, along with recent radial velocity surveys, I integrate the orbits of over 50 000 star…
Models of red giants in the CoRoT asteroseismology fields combining asteroseismic and spectroscopic constraints
Eggenberger, P.; Valentini, M.; Poretti, E. +17 more
Context. The availability of asteroseismic constraints for a large sample of red giant stars from the CoRoT and Kepler missions paves the way for various statistical studies of the seismic properties of stellar populations.
Aims: We use a detailed spectroscopic study of 19 CoRoT red giant stars to compare theoretical stellar evolution models …
Far-infrared study of K giants in the solar neighborhood: Connection between Li enrichment and mass-loss
Zhao, G.; Muthumariappan, C.; Bharat Kumar, Yerra +1 more
Context. A small group of red giant branch (RGB) stars are known to have anomalous Li enhancement whose origin is still not well understood. Some studies have proposed that the Li enhancement in RGB stars is correlated to their far-IR excess, a result of mass loss. Studies to confirm such a correlation have a significant bearing on our understandi…
Search for exoplanet around northern circumpolar stars. Four planets around HD 11755, HD 12648, HD 24064, and 8 Ursae Minoris
Kim, S. -L.; Lee, C. -U.; Jeong, G. +7 more
Aims: This program originated as the north pole region extension of the established exoplanet survey using the 1.8 m telescope at Bohyunsan Optical Astronomy Observatory (BOAO). The aim of our paper is to find exoplanets in northern circumpolar stars with a precise radial velocity (RV) survey.
Methods: We selected about 200 northern circ…
Properties and nature of Be stars. 30. Reliable physical properties of a semi-detached B9.5e+G8III binary BR CMi = HD 61273 compared to those of other well studied semi-detached emission-line binaries
Wolf, M.; Frémat, Y.; Royer, F. +13 more
Reliable determination of the basic physical properties of hot emission-line binaries with Roche-lobe filling secondaries is important for developing the theory of mass exchange in binaries. It is a very hard task, however, which is complicated by the presence of circumstellar matter in these systems. So far, only a small number of systems with ac…