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Planetary science: The Pluto siblings

Astronomy News - 25 February 2015 - 8:41pm

Planetary science: The Pluto siblings

Nature 518, 7540 (2015).

Author: Alexandra Witze

Leslie and Eliot Young have spent their lives studying Pluto. Now they are gearing up for the biggest event of their careers.

Cosmology: A giant in the young Universe

Astronomy News - 25 February 2015 - 8:41pm

Cosmology: A giant in the young Universe

Nature 518, 7540 (2015). doi:10.1038/518490b

Authors: Bram Venemans

Astronomers have discovered an extremely massive black hole from a time when the Universe was less than 900 million years old. The result provides insight into the growth of black holes and galaxies in the young Universe. See Letter p.512

An ultraluminous quasar with a twelve-billion-solar-mass black hole at redshift 6.30

Astronomy News - 25 February 2015 - 8:41pm

An ultraluminous quasar with a twelve-billion-solar-mass black hole at redshift 6.30

Nature 518, 7540 (2015). doi:10.1038/nature14241

Authors: Xue-Bing Wu, Feige Wang, Xiaohui Fan, Weimin Yi, Wenwen Zuo, Fuyan Bian, Linhua Jiang, Ian D. McGreer, Ran Wang, Jinyi Yang, Qian Yang, David Thompson & Yuri Beletsky

So far, roughly 40 quasars with redshifts greater than z = 6 have been discovered. Each quasar contains a black hole with a mass of about one billion solar masses (109). The existence of such black holes when the Universe was less than one billion years old presents substantial challenges to theories of the formation and growth of black holes and the coevolution of black holes and galaxies. Here we report the discovery of an ultraluminous quasar, SDSS J010013.02+280225.8, at redshift z = 6.30. It has an optical and near-infrared luminosity a few times greater than those of previously known z > 6 quasars. On the basis of the deep absorption trough on the blue side of the Lyman-α emission line in the spectrum, we estimate the proper size of the ionized proximity zone associated with the quasar to be about 26 million light years, larger than found with other z > 6.1 quasars with lower luminosities. We estimate (on the basis of a near-infrared spectrum) that the black hole has a mass of ∼1.2 × 1010, which is consistent with the 1.3 × 1010 derived by assuming an Eddington-limited accretion rate.

An extremely high-altitude plume seen at Mars’ morning terminator

Astronomy News - 25 February 2015 - 8:41pm

An extremely high-altitude plume seen at Mars’ morning terminator

Nature 518, 7540 (2015). doi:10.1038/nature14162

Authors: A. Sánchez-Lavega, A. García Muñoz, E. García-Melendo, S. Pérez-Hoyos, J. M. Gómez-Forrellad, C. Pellier, M. Delcroix, M. A. López-Valverde, F. González-Galindo, W. Jaeschke, D. Parker, J. Phillips & D. Peach

The Martian limb (that is, the observed ‘edge’ of the planet) represents a unique window into the complex atmospheric phenomena occurring there. Clouds of ice crystals (CO2 ice or H2O ice) have been observed numerous times by spacecraft and ground-based telescopes, showing that clouds are typically layered and always confined below an altitude of 100 kilometres; suspended dust has also been detected at altitudes up to 60 kilometres during major dust storms. Highly concentrated and localized patches of auroral emission controlled by magnetic field anomalies in the crust have been observed at an altitude of 130 kilometres. Here we report the occurrence in March and April 2012 of two bright, extremely high-altitude plumes at the Martian terminator (the day–night boundary) at 200 to 250 kilometres or more above the surface, and thus well into the ionosphere and the exosphere. They were spotted at a longitude of about 195° west, a latitude of about −45° (at Terra Cimmeria), extended about 500 to 1,000 kilometres in both the north–south and east–west directions, and lasted for about 10 days. The features exhibited day-to-day variability, and were seen at the morning terminator but not at the evening limb, which indicates rapid evolution in less than 10 hours and a cyclic behaviour. We used photometric measurements to explore two possible scenarios and investigate their nature. For particles reflecting solar radiation, clouds of CO2-ice or H2O-ice particles with an effective radius of 0.1 micrometres are favoured over dust. Alternatively, the plume could arise from auroral emission, of a brightness more than 1,000 times that of the Earth’s aurora, over a region with a strong magnetic anomaly where aurorae have previously been detected. Importantly, both explanations defy our current understanding of Mars’ upper atmosphere.

Ancient black hole had an inexplicable growth spurt

Astronomy News - 25 February 2015 - 8:30pm

Reaching 12 billion times the mass of the sun just a billion years after the big bang, a black hole has astronomers mystified about its rapid growth

NASA Briefing to Discuss First Spacecraft Arrival at a Dwarf Planet

Astronomy News - 24 February 2015 - 11:32pm

NASA’s Jet Propulsion Laboratory (JPL) will host a briefing at noon EST (9 a.m. PST) Monday, March 2, to discuss the March 6 arrival of the agency’s Dawn spacecraft at the dwarf planet Ceres. The news briefing, held at JPL’s von Karman Auditorium at 4800 Oak Grove Dr., Pasadena, California, will be broadcast live on NASA Television and streamed on the agency’s website.

The plan to find alien life in Europa's icy seas

Astronomy News - 24 February 2015 - 9:42pm
We're getting ready to send a probe to Jupiter's icy moon – but how will we know if anything lives there?

New Images of Pluto

Astronomy News - 22 February 2015 - 10:30pm
NASA’s New Horizons spacecraft returned its first new images of Pluto on Wednesday, as the probe closes in on the dwarf planet. Although still just a dot along with its largest moon, Charon, the images come on the 109th birthday of Clyde Tombaugh, who discovered the distant icy world in 1930.

Astronomers Discover Ancient System … e Small Planets

Astronomy News - 22 February 2015 - 10:30pm
Astronomers using data from NASA's Kepler mission have discovered a planetary system of five small planets dating back to when the Milky Way galaxy was a youthful two billion years old.

Black hole's blast stunts stars

Astronomy News - 20 February 2015 - 8:31pm

The winds blasted out by supermassive black holes at the centre of galaxies are strong enough to slow the birth of new stars, astronomers reveal.

Searching for signs of Mars life could destroy them

Astronomy News - 20 February 2015 - 2:34am
A common sulphate mineral on Mars may be a signpost for habitability, but just looking for organic compounds might obliterate them

Widespread wind from black hole can shape star formation

Astronomy News - 19 February 2015 - 10:19pm

Astronomers have discovered that the winds from supermassive black holes at the centre of galaxies are blasted out in all directions. This new finding was made possible by observations with ESA's XMM-Newton and NASA's NuSTAR X-ray telescopes and it supports the picture of black holes having a significant impact on star formation of their host galaxy.

NASA, ESA Telescopes Give Shape to Furious Black Hole Winds

Astronomy News - 19 February 2015 - 9:38pm

NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) and ESA’s (European Space Agency) XMM-Newton telescope are showing that fierce winds from a supermassive black hole blow outward in all directions -- a phenomenon that had been suspected, but difficult to prove until now.

Hubble Gets Best View of a Circumstellar Debris Disk Distorted by a Planet

Astronomy News - 19 February 2015 - 9:22pm

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Over a decade before planets were found orbiting normal stars, the astronomy world was intrigued by the discovery of a vast, edge-on, pancake-flat disk of dust and gas encircling the newborn star Beta Pictoris. It appeared to validate the hypothesis by the German philosopher Immanuel Kant, 230 years ago, that our solar system was born when planets condensed from nebular material in the plane of such a disk. (This model was independently proposed by French scholar Pierre-Simon Laplace in 1796.) Kant regarded the coplanar obits of the planets a fossil skeleton of the long-ago disintegrated disk. Though nearly two dozen circumstellar debris disks have been viewed by the Hubble Space Telescope to date, Beta Pictoris is the first and best example of what a forming young planetary system looks like. That's because it can be seen edge on, and it is the only disk to date where a planet has also been imaged. Hubble has been used to intensively study the disk for the past two decades and this latest picture when compared to previous observations shows that the disk particles appear to smoothly revolve around the star like a majestic carousel. Ground-based telescopes found a Jupiter-sized world embedded in the disk in 2009, and future observations may yield more planetary objects.

Stellar intruder's daring fly-by of the solar system

Astronomy News - 19 February 2015 - 8:15pm

A nearby star passed within a light year of the sun 70,000 years ago, close enough that early humans could have seen it

Jostling photons could give dark matter away

Astronomy News - 19 February 2015 - 2:12pm

If dark matter turns out to interact with photons, its glow would be visible at the edges of spiral galaxies – now we just have to find it

VIDEO: How to create a virtual black hole

Astronomy News - 19 February 2015 - 11:22am

The Oscar nominees behind the film Interstellar explain how they created some of the visual effects in the movie.

How to predict what height meteors explode at

Astronomy News - 18 February 2015 - 8:05pm

Incoming space rocks break up and burn in the atmosphere, and their danger depends on how low they can go – now we can predict their flame-out height

'The heartbeat of the stars' An RAS public lecture on listening to sound waves i...

Astronomy News - 18 February 2015 - 6:41pm
'The heartbeat of the stars'
An RAS public lecture on listening to sound waves inside stars, by Yvonne Elsworth

The heartbeat of the stars

Royal Astronomical Society public lecture, 8 April 2014 by Prof. Yvonne Elsworth, University of Birmingham Our knowledge of how stars change and evolve under...

Explosive lithium production in the classical nova V339 Del (Nova Delphini 2013)

Astronomy News - 18 February 2015 - 3:09pm

Explosive lithium production in the classical nova V339 Del (Nova Delphini 2013)

Nature 518, 7539 (2015). doi:10.1038/nature14161

Authors: Akito Tajitsu, Kozo Sadakane, Hiroyuki Naito, Akira Arai & Wako Aoki

The origin of lithium (Li) and its production process have long been uncertain. Li could be produced by Big Bang nucleosynthesis, interactions of energetic cosmic rays with interstellar matter, evolved low-mass stars, novae, and supernova explosions. Chemical evolution models and observed stellar Li abundances suggest that at least half the Li may have been produced in red giants, asymptotic giant branch (AGB) stars, and novae. No direct evidence, however, for the supply of Li from evolved stellar objects to the Galactic medium has hitherto been found. Here we report the detection of highly blue-shifted resonance lines of the singly ionized radioactive isotope of beryllium, 7Be, in the near-ultraviolet spectra of the classical nova V339 Del (Nova Delphini 2013) 38 to 48 days after the explosion. 7Be decays to form 7Li within a short time (half-life of 53.22 days). The 7Be was created during the nova explosion via the alpha-capture reaction 3He(α,γ)7Be (ref. 5). This result supports the theoretical prediction that a significant amount of 7Li is produced in classical nova explosions.