Abundances of about 18 elements including the heavy elements Y and Zr are determined from Hubble Space Telescope Space Telescope Imaging Spectrograph ultraviolet spectra of seven extreme helium stars (EHes): LSE 78, BD +10 ...

We report an anomalous present day crustal thickness of 43–52 km beneath the 3.4–3.0 Ga mid-Archean segment of the western Dharwar craton (WDC) undisturbed by Proterozoic events. In contrast, adjoining late-Archean ...

A review of the spectroscopic properties of post-AGB stars is presented.