New solar twins and the metallicity and temperature scales of the Geneva–Copenhagen Survey

We search for ‘solar twins’ in the Geneva–Copenhagen Survey (GCS) using high-resolution optical spectroscopy. We initially select Sun-like stars from the GCS by absolute magnitude, (b − y) colour and metallicity close to the solar values. Our aim is to find the stars which are spectroscopically very close to the Sun using line depth ratios and the median equivalent widths and depths of selected li...