Dwarf Star 200 Light Years Away Contains Life's Building Blocks
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 researchers observed WD 1425+540 with the Keck Telescope in 2008 and 2014, and with the Hubble Space Telescope in 2014. Read more
Title: The Chemical Composition of an Extrasolar Kuiper-Belt-Object Author: S. Xu, B. Zuckerman, P. Dufour, E. D. Young, B. Klein, M. Jura
The Kuiper Belt of our solar system is a source of short-period comets that may have delivered water and other volatiles to Earth and the other terrestrial planets. However, the distribution of water and other volatiles in extrasolar planetary systems is largely unknown. We report the discovery of an accretion of a Kuiper-Belt-Object analogue onto the atmosphere of the white dwarf WD 1425+540. The heavy elements C, N, O, Mg, Si, S, Ca, Fe, and Ni are detected, with nitrogen observed for the first time in extrasolar planetary debris. The nitrogen mass fraction is ~ 2%, comparable to that in comet Halley and higher than in any other known solar system object. The lower limit to the accreted mass is ~ 10^22 g, which is about one hundred thousand times the typical mass of a short-period comet. In addition, WD 1425+540 has a wide binary companion, which could facilitate perturbing a Kuiper-Belt-Object analogue into the white dwarf's tidal radius. This finding shows that analogues to objects in our Kuiper Belt exist around other stars and could be responsible for the delivery of volatiles to terrestrial planets beyond
Hubble Witnesses Massive Comet-Like Object Pollute Atmosphere of a White Dwarf
Astronomers have found the first evidence of the remains of a comet-like object scattered around a burned-out star. They used NASA's Hubble Space Telescope to detect the debris, which has polluted the atmosphere of a compact star known as a white dwarf. The icy object, which has been ripped apart, is similar to Halley's Comet in chemical composition, 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 similar to our solar system's Kuiper Belt orbiting the white dwarf. This is the first evidence of comet-like material polluting a white dwarf's atmosphere. The results also suggest the presence of unseen, surviving planets around the burned-out star. Read more