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Exoplanet the size of Saturn orbiting a faint ‘ultracool dwarf’ star

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exoplanet the size of saturn orbiting a faint ultracool dwarf star

An exoplanet the size of Saturn orbiting a small faint star 35 light years away has been discovered after a radio telescope spotted a wobble in the stars motion.

This is the first time a radio telescope has been used to detect an exoplanet using the ‘wobble’ technique – the wobble is caused by the gravitational pull of the planet. 

An international team of astronomers led by the Max Planck Institute used a network of radio antennas linked together called the Very Long Baseline Array (VLBA).

The star is known as an ultracool dwarf and it is difficult to spot planets around these very faint objects – but this new technique could see many more discovered.

This is the first time a radio telescope has been used to detect an exoplanet using the 'wobble' technique - the wobble is caused by the gravitational pull of the planet

This is the first time a radio telescope has been used to detect an exoplanet using the ‘wobble’ technique – the wobble is caused by the gravitational pull of the planet

Study author Gisela Ortiz-Leon from the Max Planck Institute for Radio Astronomy (MPIfR) said the discovery was possible thanks to the extremely high precision measurements of the star’s position only possible with a radio telescope network.

The planet, called TVLM 513, has a similar mass to Saturn and an orbit similar to that of Mercury in our Solar System. 

Only a handful of extrasolar planets with characteristics similar to TVLM 513 have been discovered so far around small, cool stars due to their faintness.    

Astronomers discovered the planet using the supersharp radio ‘vision’ of the continent-wide Very Long Baseline Array (VLBA). 

This is the first discovery of an exoplanet with a radio telescope using a technique that requires extremely precise measurements of a star’s position in the sky.

It’s also only the second time a planet has been discovered using that technique for any type of telescope.

The planet was discovered thanks to a wobble in the movement of the star as it completes its orbit - the planet's gravitational pull causes it to move slightly

The planet was discovered thanks to a wobble in the movement of the star as it completes its orbit – the planet’s gravitational pull causes it to move slightly 

The technique has long been known, but has proven difficult to use as it involves tracking the star’s actual motion in space, then detecting a minuscule ‘wobble’ in that motion caused by the gravitational effect of the planet. 

The star and the planet orbit a location that represents the centre of mass for both combined and the planet is revealed indirectly if that location – called the barycenter – is far enough from the star’s centre to cause a wobble detectable by a telescope.

This technique, called the astrometric technique, is expected to be particularly good for detecting Jupiter-like planets in orbits distant from the star. 

When a massive planet orbits a star the wobble produced actually increase the further the planet is away from its host. 

Starting in June 2018 and continuing for a year and a half, the astronomers tracked a star called TVLM 513–46546, a cool dwarf with less than a tenth the mass of our Sun in the constellation Boötes. 

In addition, they used data from nine previous VLBA observations of the star between March 2010 and August 2011.

THE ASTROMETRIC TECHNIQUE: A WAY TO FIND EXOPLANETS 

There are a number of ways to find planets surrounding distant stars but a relatively untested one is the astrometric technique. 

The technique has long been known, but has proven difficult to use as it involves tracking the star’s actual motion in space.

Astronomers then work to detect a minuscule ‘wobble’ in that motion caused by the gravitational effect of the planet on the star.

The star and the planet orbit a location that represents the centre of mass for both combined.

The planet is revealed indirectly if that location – called the barycenter – is far enough from the star’s centre to cause a wobble detectable by a telescope.

This is expected to be particularly good method for detecting Jupiter-like planets in orbits distant from a star. 

When a massive planet orbits a star the wobble produced actually increase the further it is away from its host star.

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Extensive analysis of the data from those time periods revealed a telltale wobble in the star’s motion indicating the presence of a planet comparable in mass to Saturn, orbiting the star once every 221 days. 

This planet is closer to the star than Mercury is to the Sun.

Small, cool stars like TVLM 513–46546 are the most numerous stellar type in our Milky Way Galaxy, and many of them have been found to have smaller planets, comparable to Earth and Mars.

‘Giant planets, like Jupiter and Saturn, are expected to be rare around small stars like this one, and the astrometric technique is best at finding Jupiter-like planets in wide orbits, so we were surprised to find a lower mass, Saturn-like planet in a relatively compact orbit,’ according to Salvador Curiel from the University of Mexico.

‘Detecting the orbital motions of this sub-Jupiter mass planetary companion in such a compact orbit was a great challenge’, he added.

More than 4,300 planets have been discovered orbiting stars other than the Sun, but the planet around TVLM 513–46546 is only the second to be found using the astrometric technique. 

Another, very successful method, called the radial velocity technique, also relies on the gravitational effect of the planet upon the star. 

That technique detects the slight acceleration of the star, either toward or away from Earth, caused by the star’s motion around the barycenter.

‘Our method complements the radial velocity method which is more sensitive to planets orbiting in close orbits, while ours is more sensitive to massive planets in orbits further away from the star’, said Ortiz-Leon. 

‘Indeed, these other techniques have found only a few planets with characteristics such as planet mass, orbital size, and host star mass, similar to the planet we found.

Extensive analysis of the data from those time periods revealed a telltale wobble in the star's motion indicating the presence of a planet comparable in mass to Saturn, orbiting the star once every 221 days

Extensive analysis of the data from those time periods revealed a telltale wobble in the star’s motion indicating the presence of a planet comparable in mass to Saturn, orbiting the star once every 221 days

‘We believe that the VLBA, and the astrometry technique in general, could reveal many more similar planets.’

A third technique, called the transit method, also very successful, detects the slight dimming of the star’s light when a planet passes in front of it, as seen from Earth.

The astrometric method has been successful for detecting nearby binary star systems, and was recognised as early as the 19th Century as a potential means of discovering extrasolar planets. 

Over the years, a number of such discoveries were announced, then failed to survive further scrutiny. 

The difficulty has been that the stellar wobble produced by a planet is so small when seen from Earth it requires extraordinary precision in the measurements.

‘The VLBA, with antennas separated by as much as 5,000 miles, provided us with the great resolving power and extremely high precision needed for this discovery’, said Amy Mioduszewski, of the National Radio Astronomy Observatory. 

‘In addition, improvements that have been made to the VLBA’s sensitivity gave us the data quality that made it possible to do this work now’, she added.

The results are published in the current issue of the Astronomical Journal.

Scientists study the atmosphere of distant exoplanets using enormous space satellites like Hubble

Distant stars and their orbiting planets often have conditions unlike anything we see in our atmosphere. 

To understand these new world’s, and what they are made of, scientists need to be able to detect what their atmospheres consist of.  

They often do this by using a telescope similar to Nasa’s Hubble Telescope.

These enormous satellites scan the sky and lock on to exoplanets that Nasa think may be of interest. 

Here, the sensors on board perform different forms of analysis. 

One of the most important and useful is called absorption spectroscopy. 

This form of analysis measures the light that is coming out of a planet’s atmosphere. 

Every gas absorbs a slightly different wavelength of light, and when this happens a black line appears on a complete spectrum. 

These lines correspond to a very specific molecule, which indicates it’s presence on the planet. 

They are often called Fraunhofer lines after the German astronomer and physicist that first discovered them in 1814.

By combining all the different wavelengths of lights, scientists can determine all the chemicals that make up the atmosphere of a planet. 

The key is that what is missing, provides the clues to find out what is present.  

It is vitally important that this is done by space telescopes, as the atmosphere of Earth would then interfere. 

Absorption from chemicals in our atmosphere would skew the sample, which is why it is important to study the light before it has had chance to reach Earth. 

This is often used to look for helium, sodium and even oxygen in alien atmospheres.  

This diagram shows how light passing from a star and through the atmosphere of an exoplanet produces Fraunhofer lines indicating the presence of key compounds such as sodium or helium 

This diagram shows how light passing from a star and through the atmosphere of an exoplanet produces Fraunhofer lines indicating the presence of key compounds such as sodium or helium 

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Facebook users will be able to own their images and issue takedown notices

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facebook users will be able to own their images and issue takedown notices

Facebook is giving users more control over images they create, including the ability to issue takedown notices on Facebook and Instagram.

In an update on Monday, the social media firm unveiled Rights Manager, which allows creators and publishers to protect their work ‘at scale.’ 

Page administrators can submit an application for content they want protected by uploading a CSV file with all of the relevant metadata.

Once a file is accepted, Facebook’s algorithms will locate matching content on both Facebook and Instagram.

Admins can then access Facebook’s ‘fast and effective’ IP reporting system to issue takedown requests to violators. 

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An example of Facebook's new Rights Manager for Images program. Page admins can submit files they want to protect, then algorithms will find matching content on both Facebook and Instagram

An example of Facebook’s new Rights Manager for Images program. Page admins can submit files they want to protect, then algorithms will find matching content on both Facebook and Instagram

 ‘We want to ensure Facebook is a safe and valuable place for creators to share their content,’ wrote product manager Dave Axelgard.

‘That’s why we built tools like Rights Manager in Creator Studio to help creators and publishers who have a large or growing catalog of content better control when, how and where their content is shared across Facebook and Instagram.’ 

Settings can be adjusted so ownership can apply globally or only in certain territories.

Eventually all users will be able to control image rights, like they can music and video rights.

Once violators have been found, creators and publishers can choose to use Facebook's IP reporting system to issue takedown notices. The program can be made global or limited to certain territories

Once violators have been found, creators and publishers can choose to use Facebook’s IP reporting system to issue takedown notices. The program can be made global or limited to certain territories

‘We want to make sure that we understand the use case very, very well from that set of trusted partners before we expand it out because, as you can imagine, a tool like this is a pretty sensitive one and a pretty powerful one,’ Axelgard told The Verge.

‘We want to make sure that we have guardrails in place to ensure that people are able to use it safely and properly.’

Axelgard added that the company is starting small to ‘learn more and figure out the proper way to address specific use cases like memes.’

Copyright infringement has been a sensitive issue since the dawn of social media in the early 2000s.

Creatives fighting to control the use of their work have faced pushback from users claiming fair usage.

And easy access to photo-editing software raises questions about how much an image can be changed, say in a meme, before it’s no longer considered the copyrighted work.

‘Social media platforms, and the norms they have inspired, present a unique challenge to copyright law,’ intellectual property attorneys Dyan Finguerra-DuCharme and Felicity Kohn wrote last week in WWD.

‘As scholars have noted – and as any social media user can attest – social media platforms have shifted the consumption habits of today’s society from a market culture to a sharing culture by encouraging users to share freely both original and third-party content.’

And the rules about copyright and social media are hardly static.

In 2007, the Ninth Circuit ruled that embedding an image from its source did not violate the owner’s copyright because technically viewers were being directed to the website where the image was stored.

In April, a judge ruled that photographer Stephanie Sinclair didn’t have grounds to sue Mashable for embedding her photo.

But another court reversed that decision in June, holding that Instagram’s terms of service did not automatically convey the requisite ‘explicit consent’ to grant rights to a third party, according to The National Law Review.

That same month, Judge Katherine Failla refused Newsweek’s request to dismiss a copyright infringement lawsuit brought by photographer Elliot McGucken.

The legacy media company had requested McGucken’s permission to use his image of a lake in Death Valley.

When he declined, Newsweek embedded the image from McGucken’s Instagram.

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Thousands of starfish washed ashore on Florida beach after Hurricane Sally hit last week

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thousands of starfish washed ashore on florida beach after hurricane sally hit last week

Thousands of starfish washed ashore Navarre Beach after Hurricane Sally ripped through Florida last week.

Residents discovered the creatures Saturday morning, along with other animals like clams, worms and an oyster toadfish.

Biology experts say these marine animals live in the inner tidal zone of the ocean and the hurricane shifted currents that left them stranded on land.

The tropical storm hit September 16, sinking a number of boats and docks, along with releasing intense rain that flooded parts of Navarre with more than 10 feet of water.

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Thousands of starfish washed ashore Navarre Beach after Hurricane Sally ripped through Florida last week. Residents discovered the creatures Saturday morning

Thousands of starfish washed ashore Navarre Beach after Hurricane Sally ripped through Florida last week. Residents discovered the creatures Saturday morning

Danny Fureigh, chief of Navarre Beach Fire Rescue, told Pensacola News Journal: ‘You have this big surge of water coming inland from several miles out, and then washing back out with everything it touches.’

‘It’s like a big toilet bowl, pretty much. We were the only beach flying double red flags because of the water quality.’

‘We wouldn’t want our families swimming in that.’

A teacher in a video on the Navarre Beach Marine Science Station Facebook said this was the first time she has seen anything like this, but notes it does happen.  

A teacher in a video on the Navarre Beach Marine Science Station Facebook said this was the first time she has seen anything like this, but notes it does happen

The surge also brought a pin clam ashore, which situates itself vertically in the ground to filter feed on plankton floating by

A teacher in a video on the Navarre Beach Marine Science Station Facebook said this was the first time she has seen anything like this, but notes it does happen

The species of starfish Astropecten articulatus, commonly known as the Royal Starfish that was named for its bold colors. This type of starfish is found in the western part of the Atlantic Ocean and is one of the most common living around the coast of the US

The species of starfish Astropecten articulatus, commonly known as the Royal Starfish that was named for its bold colors. This type of starfish is found in the western part of the Atlantic Ocean and is one of the most common living around the coast of the US

These starfish, which are related to sand dollars, live in the inner tidal zone of the ocean and were brought to shore with the big surge from the hurricane. 

Another post by the Science Station says ‘these are royal starfish. 

The species of starfish Astropecten articulatus, commonly known as the Royal Starfish that was named for its bold colors. 

This type of starfish is found in the western part of the Atlantic Ocean and is one of the most common living around the coast of the US. 

It has a purple granulated disk, which is the central region of the sea star, and the purple color continues to extend to its five flat rays, which are its arms.’

A pin clam was also found in the white sand that situates itself into the bottom of the ocean and filter feeds, along with a number of clear jellyfish – all of which had died since being stranded on land.

Biology experts say these marine animals live in the inner tidal zone of the ocean and the hurricane shifted currents that left them stranded on land.

Biology experts say these marine animals live in the inner tidal zone of the ocean and the hurricane shifted currents that left them stranded on land.

Biology experts say these marine animals live in the inner tidal zone of the ocean and the hurricane shifted currents that left them stranded on land

Another video on the Navarre Beach Marine Science Station Facebook page shows an oyster toadfish that Hurricane Sally also brought ashore. This creature has a mouth full of teeth that it uses to crush shells of oysters and other crustaceans

Another video on the Navarre Beach Marine Science Station Facebook page shows an oyster toadfish that Hurricane Sally also brought ashore. This creature has a mouth full of teeth that it uses to crush shells of oysters and other crustaceans 

Another video on the Navarre Beach Marine Science Station Facebook page shows an oyster toadfish that Hurricane Sally also brought ashore.

‘He is a species we find commonly enough. This little guy washed ashore during the hurricane,’ the scientist said in the clip.

‘What is really cool about the oyster toadfish is his teeth.’

Hurricane Sally made landfall Wednesday near areas located near the Gulf Shores and was recorded as a Category 2 storm that pushed a surge of water onto the coast and brought torrential rain that flooded the Florida Panhandle to Mississippi

Hurricane Sally made landfall Wednesday near areas located near the Gulf Shores and was recorded as a Category 2 storm that pushed a surge of water onto the coast and brought torrential rain that flooded the Florida Panhandle to Mississippi

Pointing to the creature’s mouth, the scientist explained that it uses tiny white teeth to break open shell fish like mollusks and oysters along the bottom of the ocean.

‘He has that nice big mouth to suck in the prey and really chomp down on it.’

‘Another really unique thing about this fish is on his dorsal fin, it is flattened from being out in the sun a few days, which is actually venomous.’

Hurricane Sally made landfall Wednesday near areas located near the Gulf Shores and was recorded as a Category 2 storm that pushed a surge of water onto the coast and brought torrential rain that flooded the Florida Panhandle to Mississippi.

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Hundreds of teeth found in the Sahara Desert reveal the Spinosaurus dinosaur had aquatic lifestyle

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hundreds of teeth found in the sahara desert reveal the spinosaurus dinosaur had aquatic lifestyle

A trove of more than a thousand dinosaur teeth in the Sahara Desert confirms that the largest carnivorous dinosaur on record spent most of its time in the water.

Larger than the Tyrannosaurus, the 50-foot, seven-ton Spinosaurus lived in North Africa some 95 to 100 million years ago.

With a limited fossil record to analyze, scientists have long believed it was a land dweller.

But the discovery of a Spinosaurus tail in the prehistoric Kem Kem riverbeds in Morocco, reported in April in the journal Nature, bolstered the theory that Spinosaurus was semiaquatic and used the appendage to move through the water like an oar.

Now researchers have identified hundreds of Spinosaurus teeth in the same riverbeds, confirming the giant lizard was a real-life ‘river monster.”  

According to their report, published in the journal Cretaceous Research, the massive predator was the most common dinosaur in the Kem Kem, which flowed through the Sahara 100 million years ago.

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Spinosaurus (right) faces off against a T-rex in the movie Jurassic Park III. The 50-foot, seven-ton Spinosaurus, was the largest known carnivorous dinosaur and lived in North Africa 100 million years ago

Spinosaurus (right) faces off against a T-rex in the movie Jurassic Park III. The 50-foot, seven-ton Spinosaurus, was the largest known carnivorous dinosaur and lived in North Africa 100 million years ago 

Scientists from the University of Portsmouth say the Spinosaurus teeth were easy to identify from among the 1,200 dental remains discovered in the Kem Kem.

‘They have a smooth round cross section which glints when held up to the light,’ said researcher Aaron Quigley.

Some 1,200 teeth were sorted by species and nearly half were from Spinosaurus.

‘The huge number of teeth we collected … reveals that Spinosaurus was there in huge numbers, accounting for 45 percent of the total dental remains,’ said University of Portsmouth paleobiologist David Martill.

A team from the University of Portsmouth recovered more than 1,200 dinosaur teeth from the Kem Kem riverbeds in Morocco and nearly half belonged to Spinosauruses. That abundance, researchers say, 'is a reflection of their aquatic lifestyle'

A team from the University of Portsmouth recovered more than 1,200 dinosaur teeth from the Kem Kem riverbeds in Morocco and nearly half belonged to Spinosauruses. That abundance, researchers say, ‘is a reflection of their aquatic lifestyle’

That abundance ‘is a reflection of their aquatic lifestyle,’ Martill added.

Terrestrial dinosaurs constituted less than one percent of the dental fragments at one Kem Kem site, and barely 5 percent at another, according to the report.

‘An animal living much of its life in water is much more likely to contribute teeth to the river deposit than those dinosaurs that perhaps only visited the river for drinking and feeding along its banks,’ Martill said.

A rendering of Spinosaurus hunting a group of sawfish. The discovery of a Spinosaurus tail, first reported in April, bolstered the theory the fearsome predator spent most of its time in the river

A rendering of Spinosaurus hunting a group of sawfish. The discovery of a Spinosaurus tail, first reported in April, bolstered the theory the fearsome predator spent most of its time in the river

 ‘From this research we are able to confirm this location as the place where this gigantic dinosaur not only lived but also died. The results are fully consistent with the idea of a truly water-dwelling, ‘river monster.” 

Spinosaurus was first uncovered by German paleontologist Ernst Stromer during excavations in Egypt between 1910 and 1914.

Longer than an adult Tyrannosaurus rex, it had an elongated snout atop a crocodile-like maw that bristled with conical teeth that made it easier for it to grasp prey.

Stromer named the creature Spinosaurus, or ‘spine lizard,’ after the long distinctive spines on its back.

He brought dozens of Spinosaurus fossils back to Munich’s Paleontological Museum but they were destroyed when the city was bombed by allies in World War II.

Drawings, photos, and descriptions were all that remained until recently.

How did the fearsome Spinosaurus hunt underwater?

Spinosaurus could grow up to 50 feet long and weigh up to seven tons. 

The beasts were so large and fearsome that the adults of the species had no natural predators. 

Pictured, an artist's impression from National Geographic of two Spinosaurus hunting sawfish. Adult Spinosaurus are known to reach up to 50 feet long and weight seven tons

Pictured, an artist’s impression from National Geographic of two Spinosaurus hunting sawfish. Adult Spinosaurus are known to reach up to 50 feet long and weight seven tons

It had several adaptations that allowed it to survive and hunt underwater. 

Its nostrils were far back on its head, allowing it to breath with only a small portion of its head poking above the water level. 

Its bones were extremely dense, similar to penguins, which allowed it to carefully control its position in the water, striking a careful balance between buoyancy and submersion. 

Large, flat feet that were most probably webbed allowed it to lumber across the soft land around the river banks, while locomotion in water was similar to crocodiles. 

Its flat tail moved laterally and propelled the dinosaur forward.   

It was a therepod, the same group of dinosaurs that includes Tyranosaurus rex. 

It is the only dinosaur that is known to have swum and had huge jaws packed with six inch long razor sharp teeth. 

The teeth were conical and not blade-like, which were well adapted to hold on to the slippery prey it hunted. 

Its snout is more similar to that of crocodiles than to other predatory dinosaurs. This housed sensory structures able to capture the waves produced by swimming prey.

This organ functioned like a sonar – allowing the animal to hunt even in murky waters. 

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