New variable star 189.1904 Andromedae

Long term disc variability in the Be star o Andromedae

We present 18 years of high resolution and S/N Hα spectroscopy of the Be shell star o And, obtained between 1985–2002. Spectra taken during late 1985 show a pure photospheric profile, with disc re-formation commencing in 1986; a process that is found to occur over long timescales (∼103 days). Analysis of the evolution of the properties of the Hα shell profile suggest that the disc kinematics ar...

Luminous Red Variable Star

We report photometry and spectroscopy of the evolution of Nova Sagittarii 1994 #1 (V4332 Sagittarii) during outburst. We compare the photometric and spectral evolution of this outburst to known classes of outbursts – including classical novae and outbursts occurring on symbiotic stars – and find this object does not conform to any known class of outburst. The closest match to the behavior of th...

A new interferometric study of four exoplanet host stars: θ Cygni, 14 Andromedae, υ Andromedae and 42 Draconis⋆⋆⋆

Context. Since the discovery of the first exoplanet in 1995 around a solar-type star, the interest in exoplanetary systems has kept increasing. Studying exoplanet host stars is of the utmost importance to establish the link between the presence of exoplanets around various types of stars and to understand the respective evolution of stars and exoplanets. Aims. Using the limb-darkened diameter (...

THE AGE OF THE DIRECTLY IMAGED PLANET HOST STAR k ANDROMEDAE DETERMINED FROM INTERFEROMETRIC OBSERVATIONS

κ Andromedae, an early-type star that hosts a directly imaged low-mass companion, is expected to be oblate due to its rapid rotational velocity (v sin i=∼162 km s). We observed the star with the CHARA Array’s optical beam combiner, PAVO, measuring its size at multiple orientations and determining its oblateness. The interferometric measurements, combined with photometry and this v sin i value a...

The Dwarf Nova Pq Andromedae