New extremely r-process-enhanced star detected

Utilizing the Gran Telescopio Canarias (GTC), astronomers from the Chinese language Academy of Sciences (CAS) and elsewhere have found a brand new extraordinarily r-process-enhanced star within the Milky Way’s skinny disk. The discovering was reported in a analysis paper published July 16 on the pre-print server arXiv.

The r-process-enhanced (RPE) stars characterize a small fraction of previous, metal-poor stars, which exhibit massive enhancements in parts (equivalent to europium, thorium or uranium) produced within the speedy neutron-capture course of. These stars, which primarily populate the galactic halo and Milky Way’s dwarf satellite galaxies, are wonderful laboratories for learning the r-process and will assist us higher perceive the meeting historical past of our galaxy.

Now, a staff of astronomers led by Xiao-Jin Xie of CAS studies the detection of a brand new RPE star. They employed GTC’s Excessive Optical Decision Spectrograph (HORuS) to watch a star designated LAMOST J020623.21+494127.9 (or J 0206+4941 for brief). The observational campaign led to the classification of this object as a particularly r-process-enhanced star.

“It [J 0206+4941] was initially chosen from the LAMOST medium-resolution survey as a candidate RPE star, primarily based on its unusually sturdy traces of europium,” the researchers wrote within the paper.

The observations discovered that J 0206+4941 is a vibrant star that belongs to the Milky Way’s skinny disk. Based mostly on the collected information, the astronomers managed to derive the abundances of 30 parts for this star and to find out its kinematics.

Based on the brand new findings, J 0206+4941 has a metallicity at a stage of -0.54, an effective temperature of roughly 4,078 Okay and an abundance ratio of europium to hydrogen of 0.78. On the whole, the abundances of the sunshine parts on this star turned out to be akin to different stars of comparable metallicity and evolutionary phase, with a robust enhancement of europium and modest enhancement of barium.

The authors of the paper underlined that J 0206+4941 is due to this fact essentially the most metal-rich extremely r-process-enhanced star discovered so far. The age of the star is unsure, doubtless about 12.3 billion years, and additional research are required to substantiate this.

Making an attempt to clarify the origin of J 0206+4941, the scientists don’t exclude the likelihood that it might have been born in-situ within the Milky Way’s skinny disk. They added that it might have shaped from an interstellar medium (ISM) enriched in r-process parts by a single binary neutron star merger or core-collapsed supernovae (CCSNe).

In concluding remarks, the astronomers famous that along with J 0206+4941, in addition they recognized a couple of different metal-rich RPE candidates which can be value additional investigation utilizing devices equivalent to HORuS.

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