Institute of Astronomy

Feed aggregator

Moon water came from young wet Earth

Astronomy News - 9 May, 2013 - 19:00
Glass embedded in Apollo moon rocks hints that early Earth was born wet, and it held on to that water long enough to donate some to the moon    

(author unknown)

Supersonic cosmic winds blew up giant galactic bubbles

Astronomy News - 9 May, 2013 - 16:05
The neatly defined bubbles emerging from the centre of the Milky Way seem to have been caused by cosmic winds coming to an abrupt stop    

(author unknown)

Hubble Finds Dead Stars 'Polluted' with Planet Debris

Astronomy News - 9 May, 2013 - 15:00

Get larger image formats

Deep inside the Hyades star cluster, a pair of burned-out stars are yielding clues to the presence of rocky planets that may have whirled around them. Asteroid debris is 'raining' into the hot atmospheres of these white dwarfs. Asteroids should consist of the same material that form terrestrial planets, and seeing evidence of asteroids points to the possibility of Earth-sized planets in the same system.

(author unknown)

Meteor wonder spotted in night sky

Astronomy News - 9 May, 2013 - 14:14
People have reported seeing what was thought to be a meteor in the night sky in parts of England and Wales.(author unknown)

‘Polluted’ stellar graveyard gives glimpse of our Solar System after Sun’s implosion

Astronomy News - 9 May, 2013 - 13:21

By chemically sampling the atmospheres of two dead stars in the Hyades cluster 150 light years away, researchers at Cambridge and NASA/ESA’s Hubble Space Telescope have discovered the building blocks for Earth-sized planets formed around the stars while they lived.

The study offers insight into what will happen in our solar system when our Sun burns out 5 billion years from now. It is published today in Monthly Notices of the Royal Astronomical Society.

The dead stars - called white dwarfs - are the burned-out cores of Sun-like stars. The finding suggests that terrestrial planets formed around these white dwarfs when they were young stars.

Researchers found the white dwarfs’ atmospheres “polluted” with silicon - rocky material that makes up Earth and other terrestrial planets in our solar system.

This silicon pollution likely occurred when the dwarf’s gravity shredded asteroids that got sucked in to its pull, after asteroid belts were initially disrupted by the gravity of surviving Jupiter-sized planets - with debris settling into a ring around the dead stars similar to the rings of Saturn. 

“When these stars were born, they built planets, and there’s a good chance they are retaining some of them,” said lead investigator Dr Jay Farihi of Cambridge’s Institute of Astronomy.

“The rocks we are seeing are evidence for the Lego building blocks of planets. Both of these stars show asteroids being thrown around, which tells us that rocky planet assembly is common.”

Although the cluster is relatively young at 625 million years old, the dead stars provide clues as to what might happen when our Sun eventually burns out:

After exhausting its hydrogen fuel, the Sun will likely puff up to a red giant and destroy several terrestrial planets including Earth, losing mass as it ejects outer layers.

The balance of gravitational power between the Sun and Jupiter would change, wreaking havoc on the asteroids in the belt located between Mars and Jupiter. Some of these asteroids could veer too close to the Sun’s gravity, breaking them into debris that could be pulled into a ring around our dead Sun - similar to the inferred rings around the Hyades white dwarfs.

To conduct the new analysis, researchers used Hubble’s powerful Cosmic Origins Spectrograph to divide the stars’ ultraviolet light into its constituent colors, providing information on the chemical elements in the atmosphere.

The silicon-carbon ratio in the stars’ atmospheres rules out everything except for rock, according to researchers, who say they have chemical evidence that this material is “at least as rocky as the most primitive bodies” in our own solar system.

“The one thing the white dwarf pollution technique gives us that we just won’t get with any other planet-detection technique is the chemistry of a planet,” Farihi said.

“Based on the silicon-to-carbon ratio in our study, for example, we can actually say that this material looks like the stuff in our back yard. If you put this stuff into the hand of any human being they would be able to tell you this is a rock, they wouldn’t need to be a scientist. It’s something familiar to all of us.”

The debris most likely polluted the white dwarfs’ atmosphere when asteroids wandered too close to the stellar relics. “Basically, you need planets to throw the rocks around. It’s pretty hard to imagine another mechanism than gravity that causes material to rain down onto the star.”

Farihi suggested that asteroids less than 100 miles across were probably gravitationally torn apart by the white dwarfs. The pulverized material was pulled into a ring that could superficially resemble Saturn’s rings. The dusty material swirling in the rings eventually settled onto the stars.

The researchers estimated the asteroid’s size by measuring the amount of dust consumed by the stars, about 10 million grams per second - equal to a small river. They then compared that measurement with those from previous observations.

The team plan to analyze more white dwarfs using the same technique to identify not only the rocks’ composition but also their parent bodies. “We have been using our solar system as a kind of a map, but I don’t know what the universe does,” Farihi said. “The universe might be doing something different. We really want to build up a picture of the different families rocks.

“The beauty of this technique is that whatever the universe is doing, we’ll be able to measure it. Is there another recipe for life? The chemistry can tell us. Hopefully, with Hubble and the upcoming ground-based 30-meter telescopes, we’ll be able to tell a story.

“We can build a picture of hundreds of these things and tell how often it looks like Earth and how often it looks weird and strange. Who knows, maybe we’ll find stuff we haven’t thought of yet.”

For more information, please contact fred.lewsey@admin.cam.ac.uk

Research indicates the existence of Earth-like planets in dead solar system through latest chemical analysis techniques

solar systemstarSunHubbleastronomyplanetsJay FarihiNASAEuropean Space AgencyInstitute of AstronomyIs there another recipe for life? The chemistry can tell usJay Farihi NASA, ESA, STScI, and Z. Levay (STScI)This illustration is an artist’s impression of the thin, rocky debris disc discovered around the two Hyades white dwarfs. Rocky asteroids are thought to be perturbed by planets within the system and diverted inwards towards the star, where they break up,

This work is licensed under a Creative Commons Licence. If you use this content on your site please link back to this page.

YesNews type: Newsfpjl2

New type of supernova born in stellar smash-up

Astronomy News - 9 May, 2013 - 08:00
It's the ultimate demolition derby – stars caught in head-on collisions around a black hole may be responsible for a new kind of supernova    

(author unknown)

NASA'S Hubble Space Telescope Finds Dead Stars 'Polluted' With Planet Debris

Astronomy News - 9 May, 2013 - 05:00
NASA's Hubble Space Telescope has found the building blocks for Earth-sized planets in an unlikely place-- the atmospheres of a pair of burned-out stars called white dwarfs.(author unknown)

Toxic Mars dust could hamper planned human missions

Astronomy News - 8 May, 2013 - 19:58
The latest finds from robot explorers are boosting fears that fine-grained toxins in Martian dust will be hazardous to human explorers – and tough to avoid    

(author unknown)

Discrete clouds of neutral gas between the galaxies M31 and M33

Astronomy News - 8 May, 2013 - 08:00

Discrete clouds of neutral gas between the galaxies M31 and M33

Nature 497, 7448 (2013). doi:10.1038/nature12082

Authors: Spencer A. Wolfe, D. J. Pisano, Felix J. Lockman, Stacy S. McGaugh & Edward J. Shaya

Spiral galaxies must acquire gas to maintain their observed level of star formation beyond the next few billion years. A source of this material may be the gas that resides between galaxies, but our understanding of the state and distribution of this gas is incomplete. Radio observations of the Local Group of galaxies have revealed hydrogen gas extending from the disk of the galaxy M31 at least halfway to M33. This feature has been interpreted to be the neutral component of a condensing intergalactic filament, which would be able to fuel star formation in M31 and M33, but simulations suggest that such a feature could also result from an interaction between both galaxies within the past few billion years (ref. 5). Here we report radio observations showing that about 50 per cent of this gas is composed of clouds, with the rest distributed in an extended, diffuse component. The clouds have velocities comparable to those of M31 and M33, and have properties suggesting that they are unrelated to other Local Group objects. We conclude that the clouds are likely to be transient condensations of gas embedded in an intergalactic filament and are therefore a potential source of fuel for future star formation in M31 and M33.

Galaxy formation: The cosmic web in focus

Astronomy News - 8 May, 2013 - 08:00

Galaxy formation: The cosmic web in focus

Nature 497, 7448 (2013). doi:10.1038/497191a

Author: Robert Braun

Detection of the trace neutral fraction of hydrogen gas that stretches between the nearby Andromeda and Triangulum galaxies has allowed resolved spectral imaging of this elusive intergalactic medium. See Letter p.224

Astronomy: Baby star wind travels far

Astronomy News - 8 May, 2013 - 08:00

Astronomy: Baby star wind travels far

Nature 497, 7448 (2013). doi:10.1038/497160e

What happens in a star-forming galaxy does not stay in a star-forming galaxy. Powerful outflows from newborn stars can energize space well beyond the main boundaries of a galaxy.Sanchayeeta Borthakur at Johns Hopkins University in Baltimore, Maryland, and her colleagues used the Hubble Space

Herschel:Herschel reveals the Milky Way's warm heart

Astronomy News - 7 May, 2013 - 22:00
What heats gas near supermassive black holes at the centre of galaxies? Astronomers have looked at the centre of our Galaxy, the Milky Way, with ESA's Herschel Space Observatory and discovered a rich variety of molecules at surprisingly high temperatures - up to 1000 K. The new data suggest that the molecular gas is heated up by shocks, in addition to ultraviolet radiation from massive stars close to the Galactic Centre. Shocks develop in the gas as the material surges towards Sagittarius A*, the region harbouring the supermassive black hole at the heart of the Milky Way.(author unknown)

Glow-in-the-Dark Plants on the ISS

Astronomy News - 6 May, 2013 - 06:05
Can plants adapt to the novelty of climate change? Researchers seeking to answer this question have sent genetically engineered plants to the ISS for exposure to extreme conditions. To report their stress, the plants have learned to glow in the dark.(author unknown)

Black hole binge could test general relativity

Astronomy News - 3 May, 2013 - 17:15
Cloud of gas swirling towards the black hole at the centre of our galaxy might allow us to test Einstein's greatest theory in a new way    

(author unknown)

Astrophile: Diamond planets get even more precious

Astronomy News - 2 May, 2013 - 15:53
Milky Way miners will have to dig deeper for carbon planets than we realised – there is probably no more than one in every 1000 rocky worlds    

(author unknown)

An Anarchic Region of Star Formation

Astronomy News - 2 May, 2013 - 11:00
The Danish 1.54-metre telescope located at ESO’s La Silla Observatory in Chile has captured a striking image of NGC 6559, an object that showcases the anarchy that reigns when stars form inside an interstellar cloud.(author unknown)

Helium drought retires Herschel space telescope

Astronomy News - 1 May, 2013 - 16:52
After four years in space, the telescope that brought us galactic bubbles and water on Jupiter has run out of liquid helium and will say goodbye    

(author unknown)

Wet and wild views from the Herschel space telescope

Astronomy News - 1 May, 2013 - 16:48
Tour some of the most impressive finds made by the Herschel infrared telescope, from tangles of glowing gas to water-soaked worlds – and a hole in space    (author unknown)

NASA Spacecraft Will Visit Asteroid with New Name

Astronomy News - 1 May, 2013 - 05:00
An asteroid that will be explored by a NASA spacecraft has a new name, thanks to a third-grade student in North Carolina.(author unknown)