Category Astronomy/Space

Color image taken with the Hubble Space Telecope’s WFPC2 camera, showing the dumbbell-shaped cloud of gas and dust around the star. This nebula contains more than 10 times the mass of our Sun, which was ejected by Eta Carinae in the 19th century Great Eruption.
Credit: N. Smith (U. Arizona) and NASA.

Observations from the Gemini South and other telescopes in Chile played a critical role in understanding light echoes from a stellar eruption which occurred almost 200 years ago. Gemini spectroscopy shows that ejected material from the blast is the fastest ever seen from a star that remained intact. Imagine traveling to the Moon in just 20 seconds! That’s how fast material from a 170 year old stellar eruption sped away from the unstable, eruptive, and extremely massive star Eta Carinae.

Astro...

This is an artist impression of the collision of two stars, like the ones that formed CK Vul. The inset illustrates the inner structure of one red giant before the merger. A thin layer of 26-aluminum (brown) surrounds a helium core. An extended convective envelope (not to scale), which forms the outermost layer of the star, can mix material from inside the star to the surface, but it never reaches deep enough to dredge 26-aluminum up to the surface. Only a collision with another star can disperse 26-aluminum.
Credit: NRAO/AUI/NSF; S. Dagnello

Astronomers have made the first definitive detection of a radioactive molecule in interstellar space: a form, or isotopologue of aluminum monofluoride (26AlF)...

Observations made with ESO’s Very Large Telescope have for the first time revealed the effects predicted by Einstein’s general relativity on the motion of a star passing through the extreme gravitational field near the supermassive black hole in the center of the Milky Way. This long-sought result represents the climax of a 26-year-long observation campaign using ESO’s telescopes in Chile.

Observations made with ESO’s Very Large Telescope have for the first time clearly revealed the effects of Einstein’s general relativity on the motion of a star passing through the extreme gravitational field very close to the supermassive black hole in the center of the Milky Way. This long-sought result represents the climax of a 26-year-long observation campaign using ESO’s telescopes in Chile.

Obscure...

Satellite: Gaia Copyright: ESA/Gaia/DPAC

A thin gap has been discovered on the Hertzsprung-Russell Diagram (HRD), the most fundamental of all maps in stellar astronomy, a finding that provides new information about the interior structures of low mass stars in the Milky Way Galaxy, according to a study led by astronomers at Georgia State University.

Just as a graph can be made of people with different heights and weights, astronomers compare stars using their luminosities and temperatures. The HRD is a “family portrait” of the stars in the Galaxy, where stars such as the Sun, Altair, Alpha Centauri, Betelgeuse, the north star Polaris and Sirius can be compared...