In the surrounding milky Way halo astronomers have found a star record low of metallicness. It is reported online edition of Naked Science.
After the Big Bang, the universe consisted of hydrogen with a mixture of helium, all elements heavier than they (astrophysicists call them “metals”) were formed in the course of thermonuclear reactions generations of stars. Therefore, the older the star, the lower the metallicity (content of elements other than hydrogen and helium) and the recently discovered J0815+4729 can put in this record. An article about her Spanish scientists presented in the library of the arXiv preprints.
David Aguado, from the University of La Laguna examined millions of the spectral data of low resolution obtained in the course of large surveys of the sky, SEGUE, and LAMOST BOSS. Among them was highlighted about a hundred candidates, which can indicate nitrometallic stars. Look at them carefully, using the 4.2-meter William Herschel telescope, and then – and 10.4-meter GTC telescope which work at the Observatory Roque de Los Muchachos in the Canary Islands.
This work allowed to detect the extremely nitrometallic, neprimaluvavam dwarf star J0815+4729. Interestingly, it is situated on the farthest periphery of the milky Way, 7500 light-years from the galactic center and 32.6 thousand light-years from us. This is the region of the galactic halo – a rarefied gas, sparse stars and dark matter mass, almost invisible amid the shining of the Central regions of the Galaxy.
Temperature J0815+4729 is estimated at 6215 K, a metallicity [Fe/H] is not less -5,8, although stars with [Fe/H] below -1 are considered very old, and the young stars closer to the center of the Galaxy, it changes to +0.2. It makes J0815+4729 itself nitrometallic star known today.
Earlier it was reported that the National aerospace administration of USA (NASA) announced two major interplanetary missions, the launch of which is scheduled for mid 2020-ies.
See also: scientists have found a dwarf twin of the Solar system