Abundances in the Herbig Ae star HD 101412

Abstract

Context. Recent attention has been directed to abundance variations among very young stars. Aims. We perform a detailed abundance study of the Herbig Ae star HD 101412, taking advantage of its unusually sharp spectral lines. Methods. High-resolution spectra are measured for accurate wavelengths and equivalent widths. Balmer-line fits and ionization equlibria give a relation between T eff , and log(g). Abundance anomalies and uncertain reddening preclude the use of spectral type or photometry to fix T eff . Excitation temperatures are used to break the degeneracy between T eff and log(g). Results. Strong lines are subject to an anomalous saturation that cannot be removed by assuming a low microturbulence. By restricting the analysis to weak (≤20 mÅ) lines, we find consistent results for neutral and ionized species, based on a model with T eff = 8300 K, and log(g) = 3.8. The photosphere is depleted in the most refractory elements, while volatiles are normal or, in the case of nitrogen, overabundant with respect to the sun. The anomalies are unlike those of Ap or Am stars. Conclusions. We suggest the anomalous saturation of strong lines arises from heating of the upper atmospheric layers by infalling material from a disk. The overall abundance pattern may be related to those found for the λ Boo stars, though the depletions of the refractory elements are milder, more like those of Vega. However, the intermediate volatile zinc is depleted, precluding a straightforward interpretation of the abundance pattern in terms of gas-grain separation.

Fingerprints of giant planets in the photospheres of Herbig stars

“…The abundances for HD 100546 are from Kama et al (2015) and for HD 34282 from Merín et al (2004). HD 101412 was identified as a λ Boö star by Cowley et al (2010), we use newer abundances from Folsom et al (2012). The solar abundances shown in Fig.…”

HARPS spectropolarimetry of three sharp-lined Herbig Ae stars: New insights

“…Wade et al 2005Wade et al , 2007Hubrig et al 2009Hubrig et al , 2010Hubrig et al , 2011b. The fundamental parameters, T eff = 8300 K and log g = 3.8, and the projected rotation velocity, v sin i = 3 ± 2 km s −1 , were determined by Cowley et al (2010). The inspection of the SVD I, V, and N spectra in the phase range 0.131-0.297 obtained using a sample of 650 metallic lines reveals that the amplitude of the Zeeman features increases towards the later epochs and that the majority of these features have a shape typical of that observed in classical magnetic stars during crossover, i.e.…”

The absorption and emission spectrum of the magnetic Herbig Ae star HD 190073

“…Nitrogen, in particular, deserves attention, as it has been found in excess in the Herbig Ae star HD 101412 (Cowley et al 2010a). Asterisks mark cases where AW and the present work agree on possibly significant departures from solar abundances.…”