相关论文: The Origin of LAMOST J1109+7459

Learning about the chemical evolution of the universe is crucial to understanding the formation of the first stars and structure formation in the early universe. To find out how elements are produced via nucleosynthesis and how their…

We analyse high signal-to-noise ESPaDOnS/CFHT spectra of 20 very metal-poor stars (VMP; [Fe/H]~$<-2.0$) in the solar neighbourhood (within $\sim2$ kpc), selected to be on planar orbits with maximum heights $\lesssim4$ kpc. The sample…

We report the discovery of RAVE J203843.2-002333, a bright (V = 12.73), very metal-poor ([Fe/H] = -2.91), r-process-enhanced ([Eu/Fe] = +1.64 and [Ba/Eu] = -0.81) star selected from the RAVE survey. This star was identified as a metal-poor…

We present the discovery of HE0144-4657, an ultra metal-poor, CNO-enhanced star dynamically associated with the Helmi Stream disrupted dwarf-galaxy remnant. This star was first identified as a carbon-enhanced, metal-poor star candidate from…

We report on the chemo-dynamical analysis of SPLUS J142445.34-254247.1, an extremely metal-poor halo star enhanced in elements formed by the rapid neutron-capture process. This star was first selected as a metal-poor candidate from its…

We report the discovery of the young B6V run-away star LAMOST J083323.18+430825.4, 2.5\,kpc above the Galactic plane. Its atmospheric parameters and chemical composition are determined from LAMOST spectra, indicating normal composition.…

We present a high-resolution (R~35,000), high signal-to-noise (S/N>200) Magellan/MIKE spectrum of the star RAVE J094921.8-161722, a bright (V=11.3) metal-poor red giant star with [Fe/H] = -2.2, identified as a carbon-enhanced metal-poor…

We report on the spectroscopic analysis of RAVE J183013.5-455510, an extremely metal-poor star, highly enhanced in CNO, and with discernible contributions from the rapid neutron-capture process. There is no evidence of binarity for this…

Context: The discovery and chemical analysis of extremely metal-poor stars permit a better understanding of the star formation of the first generation of stars and of the Universe emerging from the Big Bang. aims: We report the study of a…

We present a high-resolution ($R\sim35,000$), high signal-to-noise ($S/N=350$) Magellan/MIKE spectrum of the bright extremely metal-poor star 2MASS~J1808$-$5104. We find [Fe/H] = $-$4.01 (spectroscopic LTE stellar parameters), [Fe/H] =…

Pristine_183.6849+04.8619 (P1836849) is an extremely metal-poor ([Fe/H]$=-3.3\pm0.1$) star on a prograde orbit confined to the Galactic disk. Such stars are rare and may have their origins in protogalactic fragments that formed the early…

WD J204713.76-125908.9 is a new addition to the small class of white dwarfs with helium-dominated photospheres that exhibit strong Balmer absorption lines and atmospheric metal pollution. The exceptional abundances of hydrogen observed in…

Using the Large Binocular Telescope (LBT)/Multi-Object Dual Spectrograph (MODS), we have obtained optical spectroscopy of one of the most metal-poor dwarf star-forming galaxies (SFG) in the local Universe, J2229+2725. This galaxy with a…

We report on the elemental abundances of the carbon-enhanced metal-poor (CEMP) star J2217+2104 discovered by our metal-poor star survey with LAMOST and Subaru. This object is a red giant having extremely low Fe abundance ([Fe/H]=-4.0) and…

The first stars formed out of pristine gas, causing them to be so massive that none are expected to have survived until today. If their direct descendants were sufficiently low-mass stars, such stars could exist today and would be…

We present a chemical abundance analysis of the faint halo metal-poor main-sequence star J0023+0307, with [Fe/H]<-6.3, based on a high-resolution (R~35,000) Magellan/MIKE spectrum. The star was originally found to have [Fe/H]< -6.6 based on…

We report the discovery of the carbon-rich ultra metal-poor unevolved star J0815+4729. This dwarf star was selected from SDSS/BOSS as a metal-poor candidate and follow-up spectroscopic observations at medium-resolution were obtained with…

The similarity in physical conditions in winds of low-mass post-asymptotic giant branch stars and evolved massive stars leads to the appearance of an interesting phenomenon of spectral mimicry. Due to that the discovery of every new star…

We present a comprehensive spectroscopic and kinematic analysis of the very metal-poor ([Fe/H] = -2.60 $\pm$ 0.20 dex) giant star HE2159-0551. By investigating the star's chemodynamic characteristics, we seek to address its formation,…

LAMOST J052016.79+345651.7 was identified as an EW-type eclipsing binary by Chen et al. when studying the periodic variable stars based on the ZTF telescope. An orbital period of 0.3507818 days has been reported. Using the ZTF g, r, i band…