Thursday 2 August 2018

Astronomers Uncover New Clues to the Star that Wouldn’t Die


It takes more than a massive outburst to destroy the mammoth star Eta Carinae, one of the brightest known stars in the Milky Way galaxy. About 170 years ago, Eta Carinae erupted, unleashing almost as much energy as a standard supernova explosion.

Yet that powerful blast wasn’t enough to obliterate the star, and astronomers have been searching for clues to explain the outburst ever since. Although they cannot travel back to the mid-1800s to witness the actual eruption, they can watch a rebroadcast of part of the event — courtesy of some wayward light from the explosion. Rather than heading straight toward Earth, some of the light from the outburst rebounded or “echoed” off of interstellar dust, and is just now arriving at Earth. This effect is called a light echo.

The surprise is that new measurements of the 19th-century eruption, made by ground-based telescopes, reveal material expanding with record-breaking speeds of up to 20 times faster than astronomers expected. The observed velocities are more like the fastest material ejected by the blast wave in a supernova explosion, rather than the relatively slow and gentle winds expected from massive stars before they die.

Based on the new data, researchers suggest that the 1840s eruption may have been triggered by a prolonged stellar brawl among three rowdy sibling stars, which destroyed one star and left the other two in a binary system. This tussle may have culminated with a violent explosion when Eta Carinae devoured one of its two companions, rocketing more than 10 times the mass of our Sun into space. The ejected mass created gigantic bipolar lobes resembling the dumbbell shape seen in present-day images.


via Hubble - News feed
http://hubblesite.org/news_release/news/2018-33

Astronomers blown away by historic stellar blast

more »
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.
via Science Daily
Zazzle Space Exploration market place

A nature-lover’s guide to CERN

Fast, cheap and colorful 3-D printing

more »
People are exploring the use of 3-D printing for wide-ranging applications, including manufacturing, medical devices, fashion and even food. But one of the most efficient forms of 3D printing suffers from a major drawback: It can only print objects that are gray or black in color. Now, researchers have tweaked the method so it can print in all of the colors of the rainbow.
via Science Daily