giant stars tagged posts

An optical image of the brightest globular cluster, Omega Centauri, a group of over ten million stars older than the Sun. Astronomers have developed a new computational method to determine the abundance of oxygen in these and similar stars, and in particular in giant stars. The code finds values that are more self-consistent than previous estimates. Credit: Joaquin Polleri & Ezequiel Etcheverry, Observatorio Panameño en San Pedro de Atacama

Oxygen is the 3rd most abundant element in the universe, after hydrogen and helium. It is an important constituent of the clouds of gas and dust in space, especially when combined in molecules with other atoms like carbon, and it is from this interstellar material that new stars and planets develop...

Artist’s concept of a giant extrasolar planet. Credit: NASA/JPL-Caltech.

The giant planets have masses from 2.4 to 5.5 the mass of Jupiter and have very long orbital periods ranging from nearly 2 to slightly more than 4 Earth years. The team, led by Matias Jones of the Pontifical Catholic University of Chile, made the discovery during observations under the EXPRESS (EXoPlanets aRound Evolved StarS) radial velocity program. They used 2 telescopes located in the Atacama desert in Chile: the 1.5 m telescope at the Cerro Tololo Inter-American Observatory and the 2.2 m telescope at La Silla observatory. Complementary observations were conducted at the 3.9 m Anglo-Australian telescope in Australia.

Using spectrographs mounted on these telescopes, the researchers were monitoring a sample of 166 b...