population II

population II

[‚päp·yə′lā·shən ′tü]
(astronomy)
A class of stars which are relatively old and evolved, have low metallic content and high peculiar velocities from 60 to 300 miles (100 to 500 kilometers) per second, and are found chiefly in the spheroidal halo of a galaxy. Also known as halo population.
References in periodicals archive ?
Ibraimov AI, Kazakova AK, Moldotashev IK, Sultanmuratov MT, Abdyev KS (2010) Variability of Human Body Heat Conductivity in Population II.
The Helium Flash "After a star of Population II has evolved away from the main sequence of the Hertzsprung-Russell diagram and become a red giant star, a remarkable 'thermal runaway' occurs deep in its interior.
On the other hand, the less luminous reddish stars typical of Population II are abundant toward the center of the system, in Sagittarius.
Population II was a 98-chromosome hybrid that originated from a cross that involved an unreduced L.
19365-3 is a small, red dry bean developed from an interspecific Population II (Florida 6-19/Pc-46) using a modified bulk selection of 10 plants for three continuous generations.
Prior Information Notice: Adding and innovation systems to monitor air pollution load in the czech republic on the health of the population ii.
If its existence is confirmed, perhaps this locally delayed generation of very-low-metallicity stars should be called Population 0, since Population I stars are metal-rich stars and Population II stars are moderately metal-poor.
This led to his discovery, published in 1944, of two "populations" of stars--Population I, comprised of relatively young stars and clusters confined to the galactic plane, especially the spiral arms, and Population II, consisting of relatively old stars and clusters that occupy a spherical halo around the galactic center.
2 percent as much mass as its galaxy's central bulge--the galaxy's spherical or ellipsoidal concentration of old, yellow, Population II stars (S&T: October 2000, page 28).
Since dwarf galaxies are dominated by old, reddened Population II stars, Freeman points out, this result is not surprising.
For example, not until Walter Baade recognized two distinct stellar populations in M31 - the young, blue stars of Population I in the disk versus the old, yellow stars of Population II in the hub - did it become possible to understand the Milky Way's own spiral structure.

Full browser ?