Is There NbO in S-Type Stars?

Abstract

Because of numerous close coincidences with important ZrO bandheads, it is difficult to determine conclusively the presence or absence of bands of NbO in spectra of S-type stars. The only bands which appear favorable for detection of NbO are X 6484 and X 6591. These appear to be weakly present on a spectrogram of R Cygni taken at a cool phase.The abundance ratio, Nb/Zr, presumably varies during the synthesis of Tc (Anders 1958; Amould 1967). The importance of determining relative abundances of Zr, Nb, Mo, Tc, and Ru in cool stars has already been stressed (Davis 1968). This would be a very extensive project. In the present paper we shall be concerned only with niobium.

Anomalous Vibrational Dependence of the Rotational and Hyperfine Parameters in the B4Π–X4Σ− Transition of NbO

“…A second reason was astrophysical. The presence of NbO in the spectrum of the S-type star R Cygni has been tentatively established (11,12) by means of the bandheads at 6484 and 6591Å. When that work was done the bands had not been assigned, but Féménias et al (5) later showed that they are the = 3/2-1/2 and 1/2-1/2 components of the B 4 -X 4 − (0,0) band.…”

Phenomenological Viscoelasticity of a Heterogeneous Pharmaceutical Semisolid

“…It has been reported that a t least 24 hr were necessary for stresses produced in anhydrous lanolin by sample loading to relax prior to creep testing (18). In this study, it was not feasible to permit each sample to relax 24 hr before testing.…”