Stars

Artistic representation of the HD 131399 system with its exoplanet and its three stars (Image ESO/L. Calçada)

An article published in the journal “Science” describes the discovery of the exoplanet HD 131399Ab, the first ever found in a system with three suns. A team of astronomers led by the University of Arizona used the SPHERE instrument mounted on ESO’s VLT to obtain a direct image of HD 131399Ab and its system’s three stars. Scientists thought that such an orbit was unstable but this case seems to contradict that idea.

Artist's impression of the simultaneous stellar eclipse with the planetary transit events by Kepler-1647b (Image Lynette Cook)

An article published in “The Astrophysical Journal” describes the study of the planet’s characteristics circumbinary Kepler-1647b. By using the Kepler space telescope NASA, a team of scientists at NASA’s Goddard Space Flight Center and the San Diego State University led by Veselin Kostov discovered this planet that orbits two stars. This is not the first case of this kind but it’s the biggest and its year is longer, about three Earth’s years.

The galaxy UGC 9391 seen by the Hubble Space Telescope. Cepheid variable are in red circles, a type Ia supernova is marked by a blue cross (Image NASA, ESA, and A. Riess (STScI/JHU))

An article accepted for publication in “The Astrophysical Journal” describes a research based on observations made with the Hubble Space Telescope that suggests that the universe is expanding at a faster rate than expected. A team of astronomers led by Nobel laureate Adam Riess measured the distance of stars in nineteen galaxies with the best accuracy ever achieved to obtain this surprising result.

Representation of a solar superflare (Image NASA's Goddard Space Flight Center, Greenbelt, Md.)

An article published in the journal “Nature Geoscience” describes a study on the relationship between super solar flares of a few billion years ago and the emergence of life forms on Earth. According to a team of NASA scientists led by Vladimir Airapetian those gigantic storms provided the energy needed to warm up the Earth and to trigger some chemical reactions needed to form complex molecules such as RNA and DNA on which life is based.