Photometry and low-resolution spectroscopy have added V2552 Oph to the rare class of R Coronae Borealis variables. We confirm this classification of V2552 Oph through a comparison of our high-resolution optical spectrum of this star and that of R CrB and other F-type members of the class. We show that V2552 Oph most closely resembles Y Mus and FH Sct, stars in which Sr, Y, and Zr are enhanced. ...

Surface abundances of 14 (11 majority class and three minority class) R Coronae Borealis stars (RCBs) along with the final-flash object, V4334 Sgr (Sakurai's object) are revised based on their carbon measured from observed C2 bands; note that earlier reported were derived using an assumed abundance due to well-known problem. The hot RCB star MV is not subject a problem; it remarkable Sgr's lies...

Venus, a planet similar to Earth in heat budget lacks plate tectonics, yet displays ample evidence of extensive volcanic and tectonomagmatic processes, including regions large enough to be considered LIPs. Thus Venus provides an excellent opportunity to examine large-scale magmatic processes outside a plate tectonic framework. I discuss four groups of Venus’ largest tectonomagmatic provinces: v...