Bibcode
DOI
Israelian, G.; Lobel, A.; Schmidt, M. R.
Bibliographical reference
The Astrophysical Journal, Volume 523, Issue 2, pp. L145-L149.
Advertised on:
10
1999
Journal
Citations
19
Refereed citations
17
Description
High-resolution near-ultraviolet spectra of the yellow hypergiants HR
8752 and rho Cassiopeiae indicate high effective temperatures, placing
both stars near the low-T_eff border of the ``yellow evolutionary
void.'' At present, the temperature of HR 8752 is higher than ever. For
this star we found T_eff=7900+/-200 K, whereas rho Cassiopeiae has
T_eff=7300+/-200 K. Both HR 8752 and rho Cassiopeiae have developed
strong stellar winds with V_∞~=120 and V_∞~=100 km s^-1,
respectively. For HR 8752 we estimate an upper limit for the spherically
symmetric mass loss of 6.7x10^-6 M_solar yr^-1. Over the past decades
two yellow hypergiants appear to have approached an evolutionary phase,
which has never been observed before. We present the first spectroscopic
evidence of the blueward motion of a cool super/hypergiant on the H-R
diagram.