Astronomy

Ageism is a widespread global prejudice. It's about time we started acknowledging our unconscious bias towards old age – not least because our own future health depends on it

The International Space Station was caught on camera in an incredible new photo from HEO Robotics, which images satellites using space-based sensors.

A newly discovered giant planet is the density of a vast cloud of cotton candy. The sweet discovery of WASP-193 b marks the entry of the second-lightest exoplanet ever seen into the exoplanet catalog.

Human’s evolutionary remnants show us the kinds of animals we used to be

With big announcements about the latest artificial intelligence models this week, tech firms are competing to have the most exciting products - but generative AI remains hampered by issues

With big announcements about the latest artificial intelligence models this week, tech firms are competing to have the most exciting products - but generative AI remains hampered by issues

Researchers aiming to create a secure quantum version of the internet need a device called a quantum repeater, which doesn't yet exist - but now two teams say they are well on the way to building one

Researchers aiming to create a secure quantum version of the internet need a device called a quantum repeater, which doesn't yet exist - but now two teams say they are well on the way to building one

A solar energy absorber that uses quartz to trap heat reached 1050°C in tests and could offer a way to decarbonise the production of steel and cement

A solar energy absorber that uses quartz to trap heat reached 1050°C in tests and could offer a way to decarbonise the production of steel and cement

If a building is hit with an earthquake or explosives, the entire thing can collapse – but a design balancing strong and weak structural connections lets part of it fall while preserving the rest

If a building is hit with an earthquake or explosives, the entire thing can collapse – but a design balancing strong and weak structural connections lets part of it fall while preserving the rest

Ageism is pervasive, accepted and invisible. Stamping out this prejudice won’t just benefit society, it will also have huge payoffs for those people who hold it

Ageism is pervasive, accepted and invisible. Stamping out this prejudice won’t just benefit society, it will also have huge payoffs for those people who hold it

A preview of NASA's latest issue of "Astrobiology," their fun ongoing graphic novel series

A new planet candidate discovered in data from NASA's TESS mission could be an extreme lavaworld, pushed and pulled by the gravity of its own star and two other close-in planets.

The post Planet Candidate Could Be Incandescent with Lava Flows appeared first on Sky & Telescope.

Astronomers have determined that the Milky Way's outer halo is filled with "magnetic donuts" that are as wide as 100,000 light-years. The discovery could shed light on how cosmic magnetic fields form and evolve.

An illuminated waning gibbous moon contrasts the deep black of space as the International Space Station soared 270 miles over the Southern Ocean.

Astronomers have discovered an Earth-size planet orbiting a red dwarf star, making just the second planetary system seen around one of these tiny, cool, dim, but common, stars.

Mention the Milky Way and most people will visualise a great big spiral galaxy billions of years old. It’s thought to be a galaxy that took shape billions of years after the Big Bang. Studies by astronomers have revealed that there are the echo’s of an earlier time around us. A team of astronomers from MIT have found three ancient stars orbiting the Milky Way’s halo. The team think these stars formed when the Universe was around a billion years old and that they were once part of a smaller galaxy that was consumed by the Milky Way. 

The Milky Way is our home galaxy within which our entire Solar System and an estimated 400 billion other stars. It measures 100,000 light years from sided to side and is home to almost everything else we can see in the sky with our naked eyes. On a clear dark night we can see the combined light from all the stars in the galaxy forming a wonderful band of hazy light arching across the sky from horizon to horizon. If you could view the Galaxy from the outside its broad shape would resemble two fried eggs stuck back to back.

The story of the discovery takes us back to 2022 during a new Observational Stellar Archaeology course at MIoT when students were learning how they can analyse ancient stars. They then applied them to stars that have not yet been analysed. They worked with data from the 6.5m Magellan-Clay telescope at Las Campanas Observatory and were searching for stars that had formed soon after the Big Bang. At this time in the evolution of the Universe, there was mostly hydrogen and helium with trace amounts of strontium and barium. The team therefore searched for stars with spectra indicating these elements. 

Precision manufacturing is at the heart of the Giant Magellan Telescope. The surface of each mirror must be polished to within a fraction of the wavelength of light. Image: Giant Magellan Telescope Organization

They honed in on just three stars that had been observed in 2013 and 2014 but they had not been previously analysed so were a great study for the students. On completion of their analysis (which took several hundred hours at a computer), the team identified that the stars had very low levels of strontium and barium as predicted if they were ancient stars. The stars they studied were estimated at having formed between 12 and 13 billion years ago. What wasn’t clear was the origin of the stars.  How did they come to be in the Milky Way given that it was relatively new and young. 

The team decided to analyse the orbital characteristics of the stars to see how they moved. The stars were all in different locations through the Milky Way’s halo and all thought to be about 30,000 light years from Earth. Comparing the motion with data from the Gaia astrometric satellite they discovered the stars were going in the opposite direction to the majority of other stars in the Milky Way. We call this retrograde motion and it suggests the stars came from somewhere else, not having formed with the Milky Way. The chemical signatures of the stars coupled with their motion give strong credibility to the liklihood these ancient stars are not native to the Milk Way.

Now they have developed there approach to identify ancient stars, the students are keen to expand their search to see if any others can be located. However with 400 billion stars in the Milky Way, a slightly more efficient method needs to be found. 

Source : MIT researchers discover the universe’s oldest stars in our own galactic backyard

The post Three of the Oldest Stars in the Universe Found Circling the Milky Way appeared first on Universe Today.