Category Astronomy/Space

AG Carinae (AG Car) – an example of a Luminous Blue Variable (LBV) star. Credit: Judy Schmidt/Hubble Space Telescope.

A new study based on the first Gaia data release (DR1) reveals more accurate measurements of the distance of four canonical luminous blue variables (LBVs) in the Milky Way galaxy. DR1 contains a catalog of over 1 billion stars with precise measurements of their brightness and positions in the sky. These data were obtained by ESA’s Gaia satellite, which is completing the first-ever “galactic census”—the most detailed 3D map of the Milky Way ever made. The release of DR1 offers the scientific community an excellent opportunity to improve knowledge of our stellar environment and to redefine previous calculations.

Combing through the data obtained by Gaia, Nathan Smith of Uni...

Artist’s impression of Earth-sized planets orbiting a red dwarf star. Credit: @ NASA, ESA, and G.Bacon (STScI)

Computer simulations by astrophysicists at the University of Bern of the formation of planets orbiting in the habitable zone of low mass stars such as Proxima Centauri show that these planets are most likely to be roughly the size of Earth and to contain large amounts of water. In August 2016, the announcement of the discovery of a terrestrial exoplanet orbiting in the habitable zone of Proxima Centauri stimulated the imagination of the experts and the general public. After all this star is the nearest star to our sun even though it is 10X less massive and 500X less luminous...

Uranus is seen in this false-color view from NASA’s Hubble Space Telescope from August 2003. The brightness of the planet’s faint rings and dark moons has been enhanced for visibility. Image credit: NASA/Erich Karkoschka (Univ. Arizona)

NASA’s Voyager 2 spacecraft flew by Uranus 30 years ago, but researchers are still making discoveries from the data it gathered then. A new study led by University of Idaho researchers suggests there could be two tiny, previously undiscovered moonlets orbiting near two of the planet’s rings. Rob Chancia, a University of Idaho doctoral student, spotted key patterns in the rings while examining decades-old images of Uranus’ icy rings taken by Voyager 2 in 1986...

This artist’s concept depicts “heartbeat stars,” which have been detected by NASA’s Kepler Space Telescope and others. Credits: NASA/JPL-Caltech

Discovered in large numbers by NASA’s Kepler, heartbeat stars are binary stars that got their name because if you were to map out their brightness over time, the result would look like an electrocardiogram. Scientists are interested in them because they are binary systems in elongated elliptical orbits. This makes them natural laboratories for studying the gravitational effects of stars on each other. In a heartbeat star system, the distance between the two stars varies drastically as they orbit each other. Heartbeat stars can get as close as a few stellar radii to each other, and as far as 10 times that distance during one orbit.

At the point of ...