Hubble: Massive Comet Ripped Apart by White Dwarf

[bystander]

Hubble Witnesses Massive Comet-Like Object Pollute Atmosphere of a White Dwarf
NASA | GSFC | STScI | HubbleSite | 2017 Feb 09

[img3="This artist's concept shows a massive, comet-like object falling toward a white dwarf. New Hubble Space Telescope findings are evidence for a belt of comet-like bodies orbiting the white dwarf, similar to our solar system's Kuiper Belt. The findings also suggest the presence of one or more unseen surviving planets around the white dwarf, which may have perturbed the belt to hurl icy objects into the burned-out star.
Image Credit: NASA, ESA, and Z. Levay (STScI)
Science Credit: NASA, ESA, and S. Xu (ESO)"]https://cdn.spacetelescope.org/archives ... c1703a.jpg[/img3][hr][/hr]

For the first time, scientists using NASA’s Hubble Space Telescope have witnessed a massive object with the makeup of a comet being ripped apart and scattered in the atmosphere of a white dwarf, the burned-out remains of a compact star. The object has a chemical composition similar to Halley’s Comet, but it is 100,000 times more massive and has a much higher amount of water. It is also rich in the elements essential for life, including nitrogen, carbon, oxygen, and sulfur.

These findings are evidence for a belt of comet-like bodies orbiting the white dwarf, similar to our solar system’s Kuiper Belt. These icy bodies apparently survived the star’s evolution as it became a bloated red giant and then collapsed to a small, dense white dwarf.

As many as 25 to 50 percent of white dwarfs are known to be polluted with infalling debris from rocky, asteroid-like objects, but this is the first time a body made of icy, comet-like material has been seen polluting a white dwarf’s atmosphere.

The results also suggest the presence of unseen, surviving planets which may have perturbed the belt and worked as a “bucket brigade” to draw the icy objects into the white dwarf. The burned-out star also has a companion star which may disturb the belt, causing objects from the belt to travel toward the burned-out star. ...

Hubble Finds Big Brother of Halley’s Comet Ripped Apart by White Dwarf
ESA Hubble Science Release | 2017 Feb 09

The Chemical Composition of an Extrasolar Kuiper-Belt-Object - S. Xu et al

• Astrophysical Journal Letters 836(1):L7 (2017 Feb 10) DOI: 10.3847/2041-8213/836/1/L7 (pdf)

[bystander]

Dwarf Star 200 Million Light-Years Away Contains Life's Building Blocks
University of California, Los Angeles | 2017 Feb 09

UCLA-led team discovers object in the constellation Boötes with carbon, nitrogen, oxygen and hydrogen

[img3="Rendering of a white dwarf star (bright white spot), with rocky debris from former asteroids or a minor planet that has been broken apart by gravity (red rings)."]http://cms.ipressroom.com.s3.amazonaws. ... rf_mid.jpg[/img3][hr][/hr]

Many scientists believe the Earth was dry when it first formed, and that the building blocks for life on our planet -- carbon, nitrogen and water -- appeared only later as a result of collisions with other objects in our solar system that had those elements.

Today, a UCLA-led team of scientists reports that it has discovered the existence of a white dwarf star whose atmosphere is rich in carbon and nitrogen, as well as in oxygen and hydrogen, the components of water. The white dwarf is approximately 200 light-years from Earth and is located in the constellation Boötes.

Benjamin Zuckerman, a co-author of the research and a UCLA professor of astronomy, said the study presents evidence that the planetary system associated with the white dwarf contains materials that are the basic building blocks for life. And although the study focused on this particular star -- known as WD 1425+540 -- the fact that its planetary system shares characteristics with our solar system strongly suggests that other planetary systems would also.

“The findings indicate that some of life’s important preconditions are common in the universe,” Zuckerman said. ...