Related papers: HD 65949: Rosetta Stone or Red Herring
We have detected four new HgMn stars, while monitoring a sample of apparently slowly rotating superficially normal bright late B and early A stars in the northern hemisphere. Important classification lines of Hg II and Mn II are found as…
We present chemical abundances derived from high-resolution Magellan/MIKE spectra of the nine brightest known red giant members of the ultra-faint dwarf galaxy Reticulum II. These stars span the full metallicity range of Ret II (-3.5 <…
Hot subluminous stars can be spectroscopically classified as subdwarf B (sdB) and O (sdO) stars. While the latter are predominantly hydrogen deficient, the former are mostly helium deficient. The atmospheres of most sdOs are almost devoid…
We report on the abundance analysis of two red giants in the faint Hercules dwarf spheroidal (dSph) galaxy. These stars show a remarkable deficiency in the neutron-capture elements, while the hydrostatic alpha-elements (O, Mg) are strongly…
To understand the origin of the abundance peculiarities of non-magnetic A-type stars, we present the first detailed chemical abundance analysis of a metallic line star HD 23193 (A2m) and an A-type subgiant HD 170920 (A5) which could have…
We have determined the abundances of several chemical elements in the atmosphere of HD 87240, a member of the young open cluster NGC 3114. We have used the code ATLAS9 to compute a model atmosphere for HD 87240 for the effective temperature…
We present new orbits for sixteen Ap spectroscopic binaries, four of which might in fact be Am stars, and give their orbital elements. Four of them are SB2 systems: HD 5550, HD 22128, HD 56495 and HD 98088. The twelve other stars are : HD…
High resolution spectra (R > 40 000) for 9 main sequence turn-off stars and 9 subgiants in the globular cluster NGC 6752 were acquired with UVES on the VLT-Kueyen (UT2). These data have been used to determine the abundances of some heavy…
UVES spectra of the very young (~10^7 years) peculiar B-type star HR 6000 were analyzed in the near-UV and visual spectral regions (3050-9460 A) with the aim to extend to other spectral ranges the study made previously in the UV using IUE…
NGC 6558 is a bulge globular cluster with a blue horizontal branch (BHB), combined with a metallicity of [Fe/H]~-1.0. It is similar to HP 1 and NGC 6522, which could be among the oldest objects in the Galaxy. Element abundances in these…
We have obtained a UVES spectrum of a slowly rotating strongly magnetic Ap star, HD 144897, that exhibits very large overabundances of rare-earth elements. Here we present a detailed spectral analysis of this object, also taking into…
We report on the chemical composition of the very metal-poor ([Fe/H]=-2.9) star LAMOST J1645+4357 that is identified to be a red giant having peculiar abundance ratios by Li et al. (2022). The standard abundance analysis is carried out for…
We present CN and CH indices and CaII triplet metallicities for 34 giant stars and chemical abundances for 33 elements in 14 giants in the globular cluster M2. Assuming the program stars are cluster members, our analysis reveals (i) an…
HD 67044 currently assigned a B8 spectral type is one of the slowly rotating B stars situated in the northern hemisphere which we are currently observing. The selection criteria for this sample of stars are a declination higher than -15^o ,…
New high resolution, very high signal-to-noise spectra of ultra-metal-poor (UMP) giant stars HD 115444 and HD 122563 have been gathered with the High-Resolution Echelle Spectrometer of the McDonald Observatory 2.7m Telescope. With these…
We present a detailed abundance analysis of the bright (V = 9.02), metal-poor ([Fe/H] = -1.47 +/- 0.08) field red horizontal-branch star HD 222925, which was observed as part of an ongoing survey by the R-Process Alliance. We calculate…
An abundance analysis based on a high-resolution spectrum is presented for a newly discovered post-AGB star in the globular cluster M79. The surprising result is that the iron abundance of the star is apparently about 0.6 dex less than that…
We present basic stellar parameters of 99 late-type G giants based on high resolution spectra obtained by the High Dispersion Spectrograph attached to Subaru Telescope. These stars are targets of a Doppler survey program searching for…
We present a Magellan/MIKE high-resolution (R ~ 35,000) spectrum of the ancient star SD 1313-0019 which has an iron abundance of [Fe/H] = -5.0, paired with a carbon enhancement of [C/Fe] ~ 3.0. The star was initially identified by Allende…
We revisit the abundances of neutron-capture elements in the metal-poor ([Fe/H]=-2.9) r-process-rich halo star CS 31082-001. Partly motivated by the development of the new near-ultraviolet Cassegrain U-band Efficient Spectrograph for the…