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Sun's mood swings not so strange after all, say scientists

AstronomyIn findings published Friday in Science, a multinational team of scientists led by Antoine Strugarek of the University of Montreal announced the Sun may not be the cosmic oddball amongst solar-type stars some astronomers believe it to be. They found that, although the Sun's cycles appear to differ from those of other stars of its type, they are governed by the same laws working in the same way.

The Sun has long been known to go through eleven-year cycles of high and low activity, including sunspots, which Strugarek likened to solar volcanoes. Times of high activity are also the most likely time for coronal mass ejections, which often emanate from sunspot regions. On rare occasions these eruptions of plasma may hit the Earth's magnetic field, setting it oscillating. It then releases previously trapped particles as the Aurora Borealis and Australis. Occasionally, the effects are so intense that these charged particles and magnetic effects can ding the performance of satellites and power grids. The poles flip at the time of high activity, and the intensity of the magnetic field peaks when the Sun is least active. A hypothetical heat-proof compass on the surface of the Sun would point toward one pole during one eleven-year period but toward the other during the next.

Astronomers discover smallest known star

AstronomyOn Wednesday, astronomers at the University of Cambridge in England announced the discovery of a dwarf star, known as EBLM J0555-57Ab, which is slightly bigger than Saturn and smaller than Jupiter. It was found using data from an array of automated telescopes called the Wide Angle Search for Planets (WASP). The study was published in the journal Astronomy & Astrophysics.

The star belongs to the Milky Way galaxy and is approximately 600 light years away from Earth. Its mean radius is about 80 percent the size of the largest planet in the Solar System, Jupiter, but despite its small size it is very dense. Its mass is almost 85±4 times the gas giant, the study said. The star's surface gravitational pull is about eleven times stronger than the Sun's — 300 times the strength by which the Earth attracts matter. It is part of a binary star system, meaning it moves around the galaxy with another star, both orbiting around the same central point. However, it stays so close to its companion star, that it takes about 7.8 days to orbit around the pair's shared centre. The distance between the two stars is less than between Mercury and the Sun, and about eight percent of an astronomical unit, in stark contrast to the 100–1000 astronomical units that typically separates two stars in such a system.

Volvo announces all new car models electric or hybrid from 2019

Engineering and TechnologyOn Wednesday, automobile company Volvo announced all of its cars to be released in 2019 onwards are to use some form of battery-powered engine, leaving conventional petrol-only vehicles altogether. The decision comes after Volvo announced in May their intent to cease production of diesel vehicles.

Astronomers reveal discovery of the hottest gas giant exoplanet known yet

AstronomyOn Monday, astronomers at the Ohio State University, Columbus, revealed the discovery of an exoplanet, named KELT-9b and according to the university's astronomy professor Scott Gaudi, it is "the hottest gas giant planet that has ever been discovered". The discovery was reported online in the Nature journal.

The astronomers say the planet's surface temperature is more than 4000°C (7232°F), nearly as hot as the Sun. The planet takes about 36 to 48 hours to orbit around its star, KELT-9. KELT-9 is about two and a half times larger than the Sun and nearly twice its temperature. The star is about 650 light years from the earth, but it is about 300 million years old. KELT-9 is a blue A-type star, which shines brightly but, unlike some other stars such as our own Sun, their life span is on the order of millions rather than billions of years.

About a year ago, NASA reports, at the Winer Observatory in Arizona, observers using the KELT-North telescope noticed a minute drop in KELT-9's brightness — about 0.5%. This pattern was observed once every one and a half days, implying the planet comes in between the line of sight of the star from Earth, meaning the planet completes one revolution in that time period. Observations using the Hubble telescope could reveal whether the planet possesses a comet-like tail, which could help the astronomers estimate how long the planet may live.

Professor Gaudi told the BBC the planet KELT-9b "is about three times the mass of Jupiter and twice as big as Jupiter." He said the team discovered the planet in 2014. He added, "it took us this long to finally convince ourselves that this truly bizarre and unusual world was in fact a planet orbiting another star".

Simulations show planet orbiting Proxima Centauri could have liquid water

AstronomyIn findings published Tuesday in Astronomy and Astrophysics, a team of scientists led by Ian Boutle at the University of Exeter have created successful simulations of two possible atmospheres of Proxima B, an exoplanet orbiting Proxima Centauri, one a simple atmosphere of nitrogen tinged with carbon dioxide and another an Earth-like mix of gases. They found it possible that liquid water, a prerequisite for life as we know it, might exist on parts of the planet.
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