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Earth-size planet discovered around cool red dwarf star shares its name with a biscuit
Three of the Oldest Stars in the Universe Found Circling the Milky Way
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 OrganizationThey 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.
Supernova-filled galaxy dazzles in new Hubble Telescope image
Hubble Views the Dawn of a Sun-like Star
2 min read
Hubble Views the Dawn of a Sun-like Star This NASA Hubble Space Telescope image captures a triple-star star system. NASA, ESA, G. Duchene (Universite de Grenoble I); Image Processing: Gladys Kober (NASA/Catholic University of America)
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Looking like a glittering cosmic geode, a trio of dazzling stars blaze from the hollowed-out cavity of a reflection nebula in this new image from NASA’s Hubble Space Telescope. The triple-star system is made up of the variable star HP Tau, HP Tau G2, and HP Tau G3. HP Tau is known as a T Tauri star, a type of young variable star that hasn’t begun nuclear fusion yet but is beginning to evolve into a hydrogen-fueled star similar to our Sun. T Tauri stars tend to be younger than 10 million years old ― in comparison, our Sun is around 4.6 billion years old ― and are often found still swaddled in the clouds of dust and gas from which they formed.
As with all variable stars, HP Tau’s brightness changes over time. T Tauri stars are known to have both periodic and random fluctuations in brightness. The random variations may be due to the chaotic nature of a developing young star, such as instabilities in the accretion disk of dust and gas around the star, material from that disk falling onto the star and being consumed, and flares on the star’s surface. The periodic changes may be due to giant sunspots rotating in and out of view.
The box in the ground-based image reveals the location of Hubble’s view within the wider context of this triple-star system. NASA, ESA, G. Duchene (Universite de Grenoble I); Image Processing: Gladys Kober (NASA/Catholic University of America); Inset: KPNO/NOIRLab/NSF/AURA/T.A. Rector (University of Alaska Anchorage/NSF’s NOIRLab)
Curving around the stars, a cloud of gas and dust shines with their reflected light. Reflection nebulae do not emit visible light of their own, but shine as the light from nearby stars bounces off the gas and dust, like fog illuminated by the glow of a car’s headlights.
HP Tau is located approximately 550 light-years away in the constellation Taurus. Hubble studied HP Tau as part of an investigation into protoplanetary disks, the disks of material around stars that coalesce into planets over millions of years.
Media Contact:
Claire Andreoli
NASA’s Goddard Space Flight Center, Greenbelt, MD
claire.andreoli@nasa.gov
Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe.
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Space Physics and Space Weather Scientist Dr. Yihua (Eva) Zheng
“I grew up in China. In China, everybody talks about what they want to be [when they grow up]. Many want to grow up to be a scientist or engineer. So I aspired to be a scientist from an early age.
“… For the girls or women in science — or in any profession or job — opportunities are more abundant than they were previously. Sometimes you need to take bold steps. Just a little push, and then you will get there. I initially started as a foreign national, so not a lot of opportunities existed for a foreign national, and some of them [required a] green card or citizenship. I think it’s hard, but still, there is a path forward. I think it’s important to work hard and be optimistic, and you will find something.”
—Dr. Yihua (Eva) Zheng, Space Physics and Space Weather Scientist, Heliophysics Science Division, NASA’s Goddard Space Flight Center
Image Credit: NASA/Thalia Patrinos
Interviewer: NASA/Thalia Patrinos
A Rotating Spacecraft Would Solve So Many Problems in Spaceflight
If you watch astronauts in space then you will know how they seem to float around their spaceship. Spaceships in orbit around the Earth are in free-fall, constantly falling toward surface fo the Earth with the surface constantly falling away from it. Any occupant is also in free-fall but living like this causes muscle tone to degrade slowly. One solution is to generate artificial gravity through acceleration in particular a rotating motion. A new paper makes the case for a rotating space station and goes so far that it is achievable now.
Acceleration is a change in either direction or speed. In a lift you can feel a deceleration as you feel heavier when the lift slows at the bottom of its descent. It would certainly be possible to generate an artificial force of gravity in a box travelling through space if it constantly accelerates. This would produce a sense of a floor and pin the occupants to the rear wall. This is however, a fairly inefficient way to produce gravity as significant amounts of fuel would be required to continually accelerate the box.
A recent paper published in Science Direct by lead author Jack J.W.A. van Loon shows how a spaceship that continuously rotates will produce an artificial gravity on the inner skin of the outer shell. The benefits to such an approach are significant; improved crew health and wellbeing, safety improvements, cost reductions and the simplification of numerous flight operations.
There are many ways that astronauts attempt to limit the impacts on health from micro-gravity. Treadmills with straps to pull the astronauts down onto the running platform are just one of the ways they attempt to keep bones and muscles in tip top condition. If they don’t then bone and muscle density declines. Research has sown that for every month in space, an astronauts’ weight bearing bones become 1% less dense. Muscles wean too and this causes problems on their return to Earth and ‘normal gravity’ so it is a vitally important part of their routine.
ESA astronaut Alexander Gerst gets a workout on the Advanced Resistive Exercise Device (ARED). Credit: NASAThe team go on to explore a number of options such as a short arm centrifuge. These would certainly generate artificial gravity but the short arm would mean the gravity gradient from foot to head of occupants would be too great and have a negative health impact. An alternate solution, and more efficient feasible solution is to build a large rotating spacecraft. Such a craft would have benefits for long term missions such as trips to Mars but also benefit those in orbit around Earth for months on end. Savings would be impressive as significant investments are made combatting the effect of microgravity.
The team discuss what would be needed to simulate and Earth-like 1g environment on a spacecraft. A donut shaped spacecraft with a 25 m radius would need to be spun 6 times per minute to generate a 1g environment. Larger spacecraft could be revolved at a slower rate. Doing so not only benefits the astronauts but nearly every aspect of life in space would be enhanced and safer; liquids would behave in a normal way, flames too would behave in a more familiar way, toilets can of a more normal design as can self care systems. The benefits are significant so I don’t think it will be long before we see astronauts walking around in revolving spacecraft enjoying the luxury of normal gravity again.
Source : Benefits of a rotating – Partial gravity – Spacecraft
The post A Rotating Spacecraft Would Solve So Many Problems in Spaceflight appeared first on Universe Today.
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SOHO’s view of the 11 May 2024 solar storm
Over the weekend of 10–12 May 2024, Earth was struck by the largest solar storm in more than a decade. While many of us enjoyed colourful auroras lighting up Earth’s protective atmosphere, spacecraft had to endure being buffeted by incredibly strong solar winds and electromagnetic radiation.
Positioned between the Sun and Earth, the ESA/NASA Solar and Heliospheric Observatory (SOHO) caught the entire solar outburst on camera. The Sun can be seen spewing out clouds of particles, with an extremely large burst sent to Earth on 11 May. The bright spots on the left and right are Jupiter and Venus.
This video was taken by SOHO’s LASCO instrument, a coronagraph made up of a telescope with a disc blocking the centre of view. By blocking out the direct light coming from the Sun, the instrument can see light from the surrounding corona.
SOHO is not the only ESA spacecraft studying solar activity and space weather. ESA’s Directorates of Science, Human and Robotic Exploration, Earth Observation, Operations, and Technology, Engineering and Quality all have missions and/or other activities directly connected with this topic. Together, they form the ESA Heliophysics observatory or more musically, ESA’s Heliophysics Orchestra.
Binoculars: A Great First Telescope
3 min read
Binoculars: A Great First Telescope A pair of good binoculars can show craters on the Moon around 6 miles (10 km) across and larger. How large is that? It would take you about two hours to hike across a similar-sized crater on Earth. The “Can You See the Flag On the Moon?” handout showcases the levels of detail that different instruments can typically observe on the Moon. Jay Tanner
Do you want to peer deeper into the night sky? Are you feeling the urge to buy a telescope? There are so many options for budding astronomers that choosing one can be overwhelming. A first telescope should be easy to use and provide good quality views while being affordable. As it turns out, those requirements make the first telescope of choice for many stargazers something unexpected: a good pair of binoculars!
Binoculars are an excellent first instrument because they are generally easy to use and more versatile than most telescopes. Binoculars can be used for activities like stargazing and birdwatching and work great in the field at a star party, along the hiking trail, and anywhere else where you can see the sky. Binoculars also travel well, since they easily fit into carry-on luggage – a difficult feat for most telescopes! A good pair of binoculars, ranging in specifications from 7×35 to 10×50, will give you great views of the Moon, large open star clusters like the Pleiades (M45), and, from dark skies, larger bright galaxies like the Andromeda Galaxy (M31) and large nebulae like the Orion Nebula (M42). While you likely won’t be able to see Saturn’s rings, as you practice your observing skills you may be able to spot Jupiter’s moons, along with some globular clusters and fainter nebulae from dark sites, too.
The two most popular types of binocular designs are shown here: roof-prism binoculars (left) and porro-prism binoculars (right). Roof prisms tend to be more compact, lighter, and a bit more portable, while porro-prisms tend to be heavier but often offer wider views and greater magnification. What should you choose? Many birders and frequent fliers often choose roof-prism models for their portability. Many observers who prefer to observe fainter deep-sky objects or who use a tripod with their observing choose larger porro-prism designs. There is no right answer, so if you can, try out both designs and see which works better for you. Astronomical Society of the Pacific
What do the numbers on those binocular specs actually mean? The first number is the magnification, while the second number is the size in millimeters (mm) of the lenses. So, a 7×35 pair of binoculars means that they will magnify 7 times using lenses 35 mm in diameter. It can be tempting to get the biggest binoculars you can find but try not to get anything much more powerful than a 10×50 pair at first. Larger binoculars with more power often have narrower fields of vision and are heavier; while technically more powerful, they are also more difficult to hold steadily in your hands and “jiggle” quite a bit unless you buy much more expensive binoculars with image stabilization or mount them to a tripod.
Would it surprise you that amazing views of some astronomical objects can be found not just from giant telescopes, but also from seemingly humble binoculars? Binoculars are able to show a much larger field of view of the sky compared to most telescopes. For example, most telescopes are unable to keep the entirety of the Pleiades or Andromeda Galaxy entirely inside the view of most eyepieces. Binoculars are also a great investment for more advanced observing, as later on they are useful for tracking down objects to then observe in more detail with a telescope.
If you are able to do so, real-world advice and experience is still the best for something you will be spending a lot of time with! Going to an in-person star party hosted by a local astronomy club is a great way to get familiar with telescopes and binoculars of all kinds – just ask permission before taking a closer look! You can find clubs and star parties near you on the Night Sky Network’s Clubs & Events page at bit.ly/nsnclubsandevents and inspire your binocular stargazing sessions with NASA’s latest discoveries!
Originally posted by Dave Prosper: November 2022
Last Updated by Kat Troche: April 2024
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