View here: Details for High-resolution spectroscopy and photometry requested for rho Cas study
Abstract: Ernst Pollmann has requested AAVSO observers’ assistance in obtaining high-resolution spectra of the very bright S Dor star rho Cas (HR 9045, 4.1-6.2 V) in support of a new long-term study. Photometry and visual observations are requested by the AAVSO.
Justification: Rho Cas is a yellow hypergiant that is demonstrating behavior that indicates it needs to be monitored closely. Klochkova et al. report significant results of their analysis of long-term high-resolution spectroscopy, and they continue: ‘In addition, photometric monitoring of the star (AAVSO) indicates that a new ejection of matter occurred in 2013, during which the brightness of the star decreased by 0.5m. Thus, the ejections in rho Cas are becoming more frequent. This may indicate that the star is approaching a crossing of the Yellow Void [of the H-R Diagram]. This fact suggests the urgent need of further monitoring of ρ Cas.’"