Category Archives: Astronomy

An international team of astronomers have used ultra-sensitive radio images to reveal thousands of star-forming galaxies in the early universe.

The scientists compiled the images using the International Low Frequency Array (LOFAR) telescope, a trans-European network of radio antennas.

It works by combining the signals from more than 70,000 antenna, located in stations across the Netherlands and in partner European countries including the UK.

By observing the same regions of sky repeatedly and combining the data to make a single very-long exposure image, the team detected the faint radio glow of stars exploding as supernovae, in tens of thousands of galaxies out to the most distant parts of the universe.

To produce the images, more than four petabytes of raw data equivalent to about a million DVDs were taken and processed.

Philip Best from the University of Edinburgh, who led the deep survey, said: When we look at the sky with a radio telescope, the brightest objects we see are produced by massive black holes at the centre of galaxies.

However, our images are so deep that most of the objects in it are galaxies like our own Milky Way, which emit faint radio waves that trace their ongoing star-formation.

The combination of the high sensitivity of LOFAR and the wide area of sky covered by our survey about 300 times the size of the full moon has enabled us to detect tens of thousands of galaxies like the Milky Way, far out into the distant universe.

The light from these galaxies has been travelling for billions of years to reach the Earth this means that we see the galaxies as they were billions of years ago, back when they were forming most of their stars.

Story continues

Team member Isabella Prandoni, from the Italian National Institute for Astrophysics in Bologna, added: Star formation is usually enshrouded in dust, which obscures our view when we look with optical telescopes. But radio waves penetrate the dust, so with LOFAR we obtain a complete picture of their star-formation.

LOFAR is operated by ASTRON, the Netherlands Institute for Radio Astronomy.

The UK is a partner country in the project, alongside Ireland, France, Germany, Italy, Latvia, the Netherlands, Poland and Sweden.

Continued here:

International astronomy team reveal images of star-forming galaxies - Yahoo Eurosport UK

When Uncle Segar Passi watches the position of the setting Sun from his front patio, he notes its location and relates that to the time of year and changes in seasonal cycles.

What he sees translates into his artworks. They are visually stunning, a rich tapestry of colours jumping off the frame with a palate that easily rivals Vincent van Gogh. This is reflected in the many awards he has garnered over the years.

His artistic talent is matched only by the depth of his wisdom and cultural knowledge, which he teaches through his practice.

Turning 79 this year, Uncle Segar is a senior Meriam elder and a Dauareb man, meaning his community is originally from Dauar, the larger of the two small islands off the coast of Mer (the other being Waier) in the eastern Torres Strait.

The volcanic trio of islands are collectively known as the Murray Island group, and sit at the very tip of the Great Barrier Reef.

Professor Martin Nakata, a Torres Strait Islander and Pro-Vice Chancellor at James Cook University, brought me to Mer years ago to help the community document its star knowledge for education and community programs.

We stood on the beach near Uncle Segars house, watching the sunset near the double-hilled island of Dauar when he told me:

That place has powerful magic. If you want to learn about traditional star knowledge, you ask those elders. Theyre the big dogs.

Looking to the artworks on the wall in Uncle Segars workshop, I noticed a plethora of subtle characteristics encoded within each one.

I know his artistic style is unique and aesthetically gorgeous, but I also know that every colour, brushstroke, motif and design has meaning. I see a painting showing a crescent Moon with the cusps pointing up. Above it are puffy cumulus clouds and the moonlight reflected in the choppy waters.

Another painting, which looks nearly identical from a distance, shows the Moon tilted at an angle. The clouds above are cirrus, and the reflection of moonlight is clear and strong on the calm, still water.

In his characteristic soft voice, Uncle Segar explained the meaning behind this pair of paintings.

Every month there is a New Moon at a different angle. Did you ever notice this?

He explained how the New Moon (kerker meb) can tell you about the changing seasons if you look at the angle of its tilt. When the cusps are pointing up (Meb metalug em), it is the dry season, the Sager.

You will see large cumulus clouds in the evening sky and the water is choppy. When the cusps point at an angle (Meb uag em), the water is calm and you see cirrus clouds. This is the wet monsoon season, the Kuki. He pointed to the painting:

If the water looks rough and the Moon is pointed up, you know the winds will die down and the next day the water will be fine.

The paintings are a medium through which complex systems of knowledge are passed down. These systems are based on generations of collective observation, deduction and interconnection a longstanding system of science.

Read more: The Moon plays an important role in Indigenous culture and helped win a battle over sea rights

Uncle Segar is an expert on clouds and weather, the plants and animals, the sea, land, and the sky. His knowledge is as deep as his artworks are captivating.

The self-taught artist developed his style in the 1960s and has since won several major awards for his work, gaining an international profile through his raw talent, complex works and lovely personality. But his passion is for local community, both on Mer and across the Torres Strait.

Uncle Segars work has appeared in local school books and seasonal calendars about traditional knowledge. He has also worked closely with me and other academics over the years, sharing Meriam Star Knowledge and co-authoring several research papers.

These include publications about traditional ways of interpreting the twinkling stars, the role of astronomy in song and dance, and the relationship between bright meteors and death rites in the Torres Strait.

Uncle Segar is currently contributing to a major book on Indigenous astronomy for a global audience and has been featured in recent Indigenous astronomy articles in Cosmos magazine. His knowledge has even been written into the Australian National Curriculum for schools across the country.

This knowledge has found its way into films by some of the worlds most critically acclaimed directors. Members of the Mer community performed the Maier (Shooting Star) dance for the 2020 Werner Herzog and Clive Oppenheimer film Fireball: Visitors from Darker Worlds.

Maier is a term from the Meriam Mir language referring to fireballs (exceptionally bright meteors), which are seen as a celestial personification of a recently deceased persons spirit flying to Beig, the land of the dead.

The brightness, trajectory and sound of a Maier all have special meaning. If the Maier breaks into fragments and you see sparks fall (uir-uir), you know that person left behind a large family.

The trajectory of the Maier tells you where that person is from. And when you hear the booming sound (dum) as the fireball explodes, it tells you that person has arrived at their destination.

The Maier dance is originally from Mer but had not been performed on the island since 1969. In late 2019, the community approved Herzog and Oppenheimer to film the dance on Mer.

Led by Meriam elder Alo Tapim, four local dancers were taught the kab kar (sacred dance) and performed it on the beach at sunset just hours later, with cameras rolling. The segment you see at the end of the film is the first time the dance had been performed on Mer in 50 years.

In 2020, his lifetime of work and his contributions to astronomy were recognised when the International Astronomical Union renamed the asteroid 1979 MH4 as 7733 Segarpassi.

This is a 1.9km-wide asteroid in the main asteroid belt between Mars and Jupiter. It is 2.4 times farther from the Sun than Earth is, and takes 3.7 years to orbit the Sun.

Read more: From 7809 Marcialangton to 7630 Yidumduma: 5 asteroids named after Aboriginal and Torres Strait Islander people

Uncle Segars important contributions to culture and science are also encapsulated in the newly released commemorative coin The Shark in the Stars.

Released on March 4, 2021 by the Royal Australian Mint, this non-circulating coin features Uncle Segars artwork. It is the third and final instalment of the Star Dreaming series, and was so popular all 5,000 coins sold out within two hours.

The celestial shark is called Beizam, a Meriam constellation formed by the bright stars of the Big Dipper (part of the Western constellation Ursa Major, the Big Bear). It traces out the head, body, fins and tail of the shark.

The changing position of the shark in the northern skies throughout the year is a seasonal marker that notes shifting seasons, when to hunt turtle, when to harvest yams, and informs the observer about the behaviour of the shark itself.

Read more: New coins celebrate Indigenous astronomy, the stars, and the dark spaces between them

When the nose of Beizam touches the horizon at sunset, sharks are feeding on sardines that swim in tight ribbons close to the shore. This occurs during the Sager, which can be a dangerous time to go for a dip.

Later in the year, as the shark dives below the horizon at dusk, you will see the first lightning of the coming monsoon.

Meriam people teach that water rushes through Beizams gills as it dives into the sea on the horizon, casting water into the sky which falls as the rains of the wet season, the Kuki.

Uncle Segar Passi continues to share his knowledge with the world, benefiting his community and the next generation of Meriam scholars. And we are exceptionally lucky and honoured to continue learning from Elders like him.

Read more: A shark in the stars: astronomy and culture in the Torres Strait

See the original post:

From fireballs in the sky to a shark in the stars: the astronomical artistry of Segar Passi - The Conversation AU

(Graphic illustration by Charlie Dillon | The Collegian)

Stargazing can be a new hobby to explore this spring as the evenings begin to warm up.

Colorado State Universitys Emily Hardegree-Ullman, assistant professor in the Colorado State University physics department and director of the on-campus Madison-Macdonald Observatory, offers some insight to this months celestial calendar.

Check out last months Written in the Stars for Fort Collins-specific beginner stargazing suggestions and to review some of the springtime constellations that are still visible.

According to in-the-sky.org, the moon will align with three different planets on the evenings of April 6, 7 and 17. The planets will be visible to the naked eye and in line with the moon. This month, Saturn will align with the moon on April 6, Jupiter on April 7 and Mars on April 17.

Following the meteor drought occurring from January to April, the Lyrid meteor shower will be best visible from the Northern Hemisphere on the nights of April 21 and 22 and into the morning of April 23, Hardegree-Ullman said.

They are going to be a little bit tricky (to see) because the moon will be pretty bright, Hardegree-Ullman said. She said the best time to spot them will be after the moon sets, in the wee hours after 4:30 in the morning. Hardegree-Ullman said the Lyrids would be most visible in the early mornings of April 22 and 23.

The Lyrids are going to be appearing to come from the direction of (the constellation) Lyra, Hardegree-Ullman said. She said stargazers can look toward the bright star, Vega, part of the constellation Lyra, in the east to try and spot the meteor shower.

This months full moon will appear up to 10% bigger than its smallest state, making it a supermoon, according to Hardegree-Ullman. Aprils full moon is always called the pink moon, named for some of the earliest flowers to bloom in spring. Hardegree-Ullman said the supermoons size may not be especially apparent, but it will be noticeably brighter than usual.

Students use this website to track International Space Station passes over a variety of locations. Hardegree-Ullman said that in Fort Collins, On April 2, 4 and 5, the ISS will be visible for multiple minutes and will be very bright.

According to Hardegree-Ullman, stargazers can look for the red giant Arcturus in the constellation Botes.

Arc to Arcturus; so if you find the Big Dipper handle, and follow it to a bright red star, youve found it, she said.

Hardegree-Ullman also said to look for the constellation Gemini and its colorful stars, Castor and Pollux. Cancer, a faint constellation, will also be visible, and its Beehive Cluster can be viewed with either binoculars or a telescope, according to Hardegree-Ullman.

Happy stargazing, Rams!

Noelle Mason can be reached atnews@collegian.comor on Twitter@noellemaso.

See original here:

Written in the Stars: April astronomy calendar The Rocky Mountain Collegian - Rocky Mountain Collegian

Artificial satellites and space junk orbiting the Earth can increase the brightness of the night sky, researchers have found, with experts warning such light pollution could hinder astronomers ability to make observations of our universe.

There are more than 9,200 tonnes of space objects in orbit around the Earth, ranging from defunct satellites to tiny fragments, according to the European Space Agency (ESA). Now it seems space junk not only poses a collision risk but, together with other space objects, is contributing to light pollution.

Writing in the Monthly Notices of the Royal Astronomical Society, researchers describe how sunlight that is reflected and scattered from space objects can appear as streaks in observations made by ground-based telescopes.

Because the streaks are often comparable to or brighter than objects of astrophysical interest, their presence tends to compromise astronomical data and poses the threat of irretrievable loss of information, the team writes.

But for some instruments, the impact could be greater still. When imaged with high angular resolution and high sensitivity detectors, many of these objects appear as individual streaks in science images, they write. However, when observed with relatively low-sensitivity detectors like the unaided human eye, or with low-angular-resolution photometers, their combined effect is that of a diffuse night sky brightness component, much like the unresolved integrated starlight background of the Milky Way.

Calculations in the report suggest this glow could reach up to 10% of the natural night sky brightness a level of light pollution previously set by the International Astronomical Union (IAU) as being the limit that is acceptable at astronomical observatory sites.

While the researchers say the idea of a natural level of brightness has its own difficulties, they stress further research is necessary, adding that the situation could become worse as further satellites, including mega-constellations, are launched.

Greg Brown, a Royal Observatory astronomer who was not involved in the study, said light pollution was a big problem for astronomers.

Telescopes like the soon-to-be-operational Vera C Rubin Observatory are expecting vast contamination of their images from just the mega-constellations expected in the next few years, which will be difficult and costly to compensate for and do seriously risk scientists missing out on key scientific discoveries, he said.

While Brown said it was unclear whether the assumptions made in the study held true, given changes in satellite design and the difficulty of estimating small space debris, he said astronomical observations would be increasingly affected by such light pollution.

This is definitely the time to be concerned about the future of both professional and amateur astronomy, he said.

Prof Danny Steeghs of the University of Warwick said there was a balance to be struck between the benefits of satellites and their impact on our ability to study the night sky, but agreed light pollution was likely to be a growing, and escalating, problem.

We can, as astronomers, remove or reduce the direct impact on our data somewhat by employing image processing techniques, but of course it would be a lot better if they are not there for starters, he said.

Fabio Falchi, from the Light Pollution Science and Technology Institute in Italy, said the problem was global. The distribution of the space debris is fairly uniform around our planet, so the contamination is already present everywhere, he said, suggesting those responsible for the problem should help to solve it.

Maybe Elon Musk can put his engineers at work to find out a solution, at least to counterbalance a little the damage that his Starlink mega-constellation of satellites is going to make to the starry sky, he said.

While projects have recently begun to clean up space junk, Steeghs said one difficulty was that small fragments could be tricky to sweep up yet could nonetheless contribute to the light pollution.

Chris Lintott, a professor of astrophysics at the University of Oxford, also stressed the need for action. It does seem that simple efforts like building satellites out of darker materials might be very helpful, and I hope operators will take such steps as soon as possible, he said.

Excerpt from:

Light pollution from satellites 'poses threat' to astronomy - The Guardian

Astrotourism has travelers jaunting to dark skies around the globe specifically for stargazing and astronomical events. USA TODAY

When Valerie Stimacspotted Hale-Bopp, that was it. She was hooked.

That unusuallybright comet,which flew by earth in the mid-1990s,sparked, her lifelong fascination with the night sky. Add to that the fact that she grew up in Alaska watching the aurora borealis on a regularly basis, and its easy to see why she fell for starry nights early on. It also makes sense that her career now focuses on all things celestial.

As the founder of Space Tourism Guide and author of "Dark Skies: A Practical Guide to Astrotourism,"she loves getting others stoked on stellar encounters through astrotourism. Which begs the questions, what exactly is astrotourism?

It encompasses any travel related to astronomy experiences, she says, whether its a solar eclipse, meteor shower, rocket launch or even something more off-worldly like taking a zero-gravity flight or eventually going to space.

If you can, try to plan your trip around an astronomy events. In 2021, Stimac says to consider the lunar occultation of Mars in April, total lunar eclipse in May, lunar occultation of Venus in November and total solar eclipse over Antarctica in December.

The best astronomical phenomena in 2020 were ones we didn't necessarily know to plan for Comet NEOWISE was only discovered in March, she says. I'm also excited for what new wonders we'll discover this year.

Here are several resorts with a focus on astronomy.

Autoplay

Show Thumbnails

Show Captions

The Wyoming wilderness is dazzling by day, of course, but by night, well, its even better. That said, theres nothing quite like staying at HotelJackson, a four-star boutique property, for a bespoke, socially distanced stargazing experience. Wyoming Stargazing takes guests to Grand Teton National Park where they can bundle up in a blanket and cozy up in a camping chair while as astronomer guides them through the cosmic display. Back at the hotel youll have views of the Snow King and the Jackson Valley Mountains. Plan a day trip to nearby Yellowstone National Park to hit the slopes or go for a hike.

Stimac recommends paying attention to the moon phase and dressing in layers. The moon is astonishingly bright and can prevent you from seeing the stars in that area of the sky, she explains. "If you want to go stargazing without the moon, aim for nights near the new moon or plan to enjoy some moongazingduring the rest of the month.

Next, don't underestimate how cold it gets once the sun goes down, she says. It's better to pack too many layers than to have your stargazing session cut short because you get cold.

Getting there: Fly into Jackson Hole Airport, and the hotels luxury car will pick you up.

Maui meets all the requirements for epic stargazing: fantastic weather all year, barely any light pollution and impeccable star visibility. HyattRegencyMauiResort and Spais a seaside escape known for its focus on the stars. For two decades, EdwardMahoney has served as the director ofastronomyforthe hotels Tour of the Stars program.Needless to say, he can answer nearly any question you come up with. And, since Maui is just 20 degrees north of the equator, guests can gaze at 80 of the 88constellations. Choose from an 8 or 9 p.m. nightly astronomy session for your glimpse of the crystal-clear skies. Or book the romance tour at 10 p.m., which comes with sparkling wine and chocolate-covered strawberries.

Nearby, The Ritz-Carlton Kapalua has a stargazing program, where guests learn about the significant role the Polynesian voyagers played in the migration to Hawaii. Plus, telescopes are available upon request so you can spot constellations throughout your stay.When youre ready to venture outside of the five-star hotel, there are miles of hiking trails to choose from and six beaches to lounge on. Once youre out of energy, treat yourself to a deep-muscle massage, oxygen-renewal facial and a coconut-mango pedicure or a private cabana by the pool. If you are there from December to March, keep those eyes peeled for whales. Thousands of humpbacks visit Mauis shores to breed and give birth in the warm waters.

Getting there: Maui is open for tourism with some travel protocols and restrictions. Hawaiian Airlines has nonstop flights from several major cities.

Four Seasons Resort, Bora Bora

The first thing that comes to mind when you think of Tahiti might be overwater bungalows and stunning turquoise water. But stargazing should also top the list. Bora Bora happens to be one of the best places to view the Southern hemisphere sky.

For the ultimate stargazing getaway, make a beeline to the Four Seasons Resort Bora Bora, where the overwater bungalows make for the perfect spot to lounge and look up at the stars. Come nighttime, get cozy on your patio lounge chairs and gaze at the night sky with the sound of waves rolling below. With no light pollution and perfect clarity, its often possible to see the Milky Way and the Southern Cross.

Many of our guests are coming for an escape from the big cities, traffic, noise and stress, says Etienne Baldeschi, head concierge at the resort. The environment here is really about privacy, romance, peace and exploration, so stargazing fits right in and is enjoyed here by almost every guest to various degrees.

To learn more about the night sky, book a stargazing session with Vavau where guests take a sunset cruise to a motu (island) and learn about how ancient Polynesians used celestial navigation.

Getting there: Youll have to wait for tourism to reopen in French Polynesia before you visit. But once it does, book an Air Tahiti Nuidirect flights from Los Angeles International Airport to Tahiti. Find the latest travel restrictions here.

At Amangiri Resort, a 600-acre paradise near Page, Arizona, guests can sign up for a complimentary stargazing session with the in-house astronomer. Theres even an astrophotographymachine that allows up to 10 users to connect wirelessly and download astro-photos from the machine directly to their device. With Amangiri being super remote, the stargazing is spectacular.

Come nighttime, rest your head in a suite with a sky terrace (that makes stagazing quite simple). During the day, spend time trekking through the national parks and kicking back at Aman Spa for a healing Navajo-inspired treatment. During the daytime, explore nearby natural wonders like majestic Grand Staircase Escalante National Monument. Adventurous types will appreciate climbing the via ferrata route, exploring slot canyons or hot-air ballooning at sunrise.

Getting there: Page Municipal Airport is located 25 minutes from Amangiri and is the closest airport.

Read or Share this story: https://www.usatoday.com/story/travel/destinations/2021/03/25/astronomy-trips-stargazing-resorts-showcase-night-sky/4235976001/

See the original post:

Astrotourism: These resorts will have you seeing stars - USA TODAY

A small portion of the Veil Nebula, which is part of a supernova remnant called the Cygnus Loop, was featured in previous Hubble photos, but now new processing techniques have been applied, bringing out fine details of the Veil Nebulas delicate threads and filaments of ionized gas.

This Hubble image shows a small portion of the Veil Nebula, which is located 2,400 light-years away in the constellation of Cygnus. Image credit: NASA / ESA / Hubble / Z. Levay.

The Cygnus Loop is a large donut-shaped nebula located approximately 2,400 light-years away from Earth.

Also known as W78 and Sharpless 103, it is actually an expanding blast wave from a supernova explosion that occurred about 15,000 years ago.

Its name comes from its position in the northern constellation of Cygnus, where it covers an area 36 times larger than the full Moon.

The visual portion of the supernova remnant is known as the Veil Nebula, also called the Cirrus Nebula or the Filamentary Nebula.

The nebulas progenitor star which was 20 times the mass of the Sun lived fast and died young, ending its life in a cataclysmic release of energy, Hubble astronomers said.

Despite this stellar violence, the shockwaves and debris from the supernova sculpted the nebulas delicate tracery of ionized gas creating a scene of surprising astronomical beauty.

To create this colorful image, of the Veil Nebula observations taken by Hubbles Wide Field Camera 3 (WFC3) instrument through five different filters were used.

The new post-processing methods have further enhanced details of emissions from doubly ionized oxygen (blue), ionized hydrogen and ionized nitrogen (red).

See the article here:

Hubble Team Releases Reprocessed Image of Veil Nebula | Astronomy - Sci-News.com

Astronomers havesearched the entire Milky Way to identify the safest places to live.It turns out, we're in a pretty good spot.

But if the past year has made you feel ready to relocate to another planet, you might want to looktoward thecenter of the galaxy, according to the new research.

The new findings were made by a group of Italian astronomers, who studied locations where powerful cosmic explosions may have killed off life. These explosions, such as supernovas and gamma-ray bursts, spew high-energy particles and radiation that can shred DNA and kill life. By this logic, regions that are more hospitable to life will be the ones without frequent explosions, the astronomers reasoned.

"Powerful cosmic explosions are not negligible for the existence of life in our galaxy throughout its cosmic history," said lead author on the new study, Riccardo Spinelli, astronomer at the University of Insubria in Italy. "These events have played a role in jeopardizing life across most of the Milky Way."

Related: 11 fascinating facts about our Milky Way galaxy

In addition to finding the deadliest hotspots, the astronomers also identified the safest places throughout the galaxy's history, going back 11 billion years. The results show that we're currently at the edge of a wide band of hospitable real estate. But in the Milky Way'syouth, the galaxy's edges were a safer bet.

Many factors make a planet habitable. For instance, planets need to be in a Goldilocks zone, where heat and activity from their host star isn't too much or too little it's just right. But in addition to these local conditions, life also has to combat harmful radiation coming from interstellar space.

Powerful cosmic events, such assupernovas and gamma-ray bursts, stream dangerous, high-energy particles at nearly the speed of light. Not only can they kill all the lifeforms we know about, but these particles can also strip entire planets of their atmospheres. After such an event, the scientists believe that planets orbiting nearby star systems would be wiped clear of life.

Related: The 9 real ways Earth could end

"For planets very close to the stellar explosion it is plausible that there is a complete sterilization," Spinelli told Live Science. "In those far away, a mass extinction is more likely."

The authors wrote in the study that a nearby gamma-ray burst may have played a leading role in theOrdovician mass extinction event around 450 million years ago the second largest in Earth's history. While there is no concrete evidence linking a specific gamma-ray burst to this extinction event, the authors think it could be likely, given Earth's position in the galaxy.

Using models of star formation and evolution, the astronomers calculated when specific regions of the galaxy would be inundated with killer radiation. Early on in the galaxy's history, the inner galaxy out to about 33,000 light-years was alight with intense star formation, which rendered it inhospitable. At this time, the galaxy was frequently rocked by powerful cosmic explosions, but the outermost regions, which had fewer stars, were mostly spared these cataclysms.

Until about 6 billion years ago, most of the galaxy was regularly sterilized by massive explosions. As the galaxy aged, such explosions became less common. Today, the mid regions, forming a ring from 6,500 light-years from the galaxy's center to around 26,000 light-years from the center, are the safest areas for life. Closer to the center, supernovas and other events are still common, and in the outskirts, there are fewer terrestrial planets and more gamma-ray bursts.

Luckily for us, our galactic neighborhood is getting more and more life-friendly. In the long-term galactic future, there will be fewer extreme events nearby that could cause another mass extinction.

The new paper's conclusions seem reasonable at first glance, Steven Desch, an astrophysicist at Arizona State University, told Live Science.

"I'm pleased to note that they do seem to put [the research] in a rigorous framework and have realistic expectations about what a gamma ray burst would do, and account for factors that sometimes people forget," such as how the energy and material released by gamma-ray bursts isnt equal in all directions, said Desch, who was not involved with the new work. "I haven't gone through their numbers in detail, but at first glance it's reasonable."

The new research, published in the March issue of the journal Astronomy and Astrophysics, might one day help astronomers decide where to search for habitable exoplanets. But for now technology limits astronomers to only searching nearby areas, Desch said.

Originally published on Live Science.

Original post:

Astronomers find the 'safest place' to live in the Milky Way - Livescience.com

YOUNGSTOWN Warren Young passionately recalled when he and Ted Pedas had witnessed a total solar eclipse nearly 50 years ago. At no time since then had anything gotten in the way of their longtime friendship.

He was a guy who took his job very seriously, said Young, a retired Youngstown State University professor who was the universitys original Ward Beecher Planetarium director from 1967 to 2004.

Seeing the rare celestial event with Pedas in July 1972 aboard a cruise ship off the coast of Africa is one of many fond memories Young has of his relationship with Pedas, an astronomy educator, philanthropist and entrepreneur who died March 11 of sudden cardiac arrest at his winter home in Sanibel Island, Fla. He was 82.

Young, who also served as chairman of YSUs physics department, remembered having met on the ship Neil Armstrong, who was the first person to walk on the moon, along with several well-known science writers.

One of the things (Pedas) had me do was introduce Neil Armstrong. I talked to him about the moon, and it was like talking to Columbus after he discovered the New World, Young said, adding that Pedas loved conducting astronomy-related lectures aboard cruise ships.

Pedas, whom Young hired at the planetarium in the late 1960s after Pedas had earned a degree from Michigan State University, also had a gift for interesting people in astronomy largely by meeting them at their age levels. For example, he had young children learn the basics about meteorites while allowing them to touch the bits of space material, Young said, adding Pedas ran astronomy shows for people of all ages, as well as school groups, several times weekly.

In 1993, after several decades at the Ward Beecher Planetarium, he was designated planetarium administrator emeritus. Pedas also was one of the International Planetarium Societys founding members in 1968.

The IPS is a global association of astronomers and other planetarium professionals. Its nearly 500 members from 50 countries represent schools, museums, universities and public facilities, including planetariums, the organizations website states.

Pedas earned degrees in planetarium science and science education from YSU, Michigan State and the University of California at Berkeley.

His entrepreneurship was evident in many ways, including donating money to, and conducting shows at, Farrell High Schools planetarium, which was renamed the Ted Pedas Planetarium largely because of his benevolence and donations to the Farrell Area School District. He also gave money for awards students were to receive, Young continued.

SPACE AGE INTEREST

Teds education and subsequent interests initially began with the start of the Space Age in the mid-1950s, Kaoru Kimura, who lives in Tokyo and is president of the International Planetarium Society, said in a statement. He combined a talent for business with a passion for teaching, particularly astronomy and space science in his hometown of Farrell, Pennsylvania.

Anthony F. Tony Aveni, an astronomy and anthropology professor at Russell Colgate University in Hamilton, N.Y., recalled that about 50 years ago, Pedas called to ask him to conduct lectures about astronomy on a cruise ship. That led to Aveni and his wife, Lorraine, spending winters in that pursuit until the pandemic began last year, he remembered.

Anyone who lives within a light year of Youngstown is well aware of Teds generosity, said Aveni, whos also a lecturer as well as editor and author of more than 20 books on ancient astronomy.

In addition, Aveni helped develop the field of archeoastronomy, the study of how ancient people came to understand astronomical events, as well as how they used and interpreted such phenomena in their cultures.

Pedas great knowledge and stellar love for his subject reverberated not only in the classroom or aboard large cruise ships, but to newspaper readers and a large segment of the public, said Sharon Shanks, who met Pedas in 1990 before succeeding him as a Ward Beecher Planetarium lecturer until she retired in 2015.

Not only did I follow him as a lecturer, but also as author of The Cosmos for The Vindicator from 1996 to 2002, Shanks remembered. He educated hundreds of thousands of people about astronomy and promoted the planetarium through that weekly column, which he wrote out by hand on yellow legal pads. He realized there was a thirst for knowledge about space and astronomy among people, and that many enjoyed learning regardless of their age.

Shanks, who retired last December after having worked 14 years as editor of Planetarian, the International Planetarium Societys journal, added that she enjoyed assisting Pedas with his cruise endeavors. In addition, Shanks lectured on two such journeys and for several years, taught once per week at the Farrell High School Planetarium for Pedas.

The 146-seat planetarium at YSU, which opened in 1967, is the first in the U.S. thats also set up as a classroom. It has undergone four major renovations, including one in 2017 to upgrade its video system, Curtis Spivey, planetarium engineer, noted.

In 2019, an estimated 20,000 people attended a variety of shows before the pandemic began last March and it had to close to the public, Spivey said, adding he hopes the facility will be able to fully reopen by fall. Now its being used in a limited capacity for students taking a basic astronomy class, he continued.

For more information about the Ward Beecher Planetarium, go to http://www.wbplanetarium.org., or visit its Facebook page.

news@tribtoday.com

Today's breaking news and more in your inbox

Read the rest here:

YSU's star of the stars remembered | News, Sports, Jobs - Youngstown Vindicator

This is an artists impression created to visualize the concentration of black holes at the center of NGC 6397. In reality, the small black holes here are far too small for the direct observing capacities of any existing or planned future telescope, including Hubble. It is predicted that this core-collapsed globular cluster could be host to more than 20 black holes. Credit: ESA/Hubble, N. Bartmann

Astronomers found something they werent expecting at the heart of the globular cluster NGC 6397: a concentration of smaller black holes lurking there instead of one massive black hole.

Globular clusters are extremely dense stellar systems, which host stars that are closely packed together. These systems are also typically very old the globular cluster at the focus of this study, NGC 6397, is almost as old as the universe itself. This cluster resides 7,800 light-years away, making it one of the closest globular clusters to Earth. Due to its very dense nucleus, it is known as a core-collapsed cluster.

At first, astronomers thought the globular cluster hosted an intermediate-mass black hole. These are the long-sought missing link between supermassive black holes (many millions of times our Suns mass) that lie at the cores of galaxies, and stellar-mass black holes (a few times our Suns mass) that form following the collapse of a single massive star. Their mere existence is hotly debated.Only a few candidates have been identified to date.

The amount of mass a black hole can pack away varies widely from less than twice the mass of our Sun to over a billion times our Suns mass. Midway between are intermediate-mass black holes weighing roughly hundreds to tens of thousands of solar masses. So, black holes come small, medium, and large. Credit: NASA, ESA, T. Brown, S. Casertano, and J. Anderson (STScI)

We found very strong evidence for an invisible mass in the dense core of the globular cluster, but we were surprised to find that this extra mass is not point-like (that would be expected for a solitary massive black hole) but extended to a few percent of the size of the cluster, said Eduardo Vitral of the Paris Institute of Astrophysics(IAP) in Paris, France.

To detect the elusive hidden mass, Vitral and Gary Mamon, also of IAP, used the velocities of stars in the cluster to determine the distribution of its total mass, that is the mass in the visible stars, as well as in faint stars and black holes. The more mass at some location, the faster the stars travel around it.

The researchers used previous estimates of the stars tiny proper motions (their apparent motions on the sky), which allow for determining their true velocities within the cluster. These precise measurements for stars in the clusters core could only be made with Hubble over several years of observation. The Hubble data were added to well-calibrated proper motion measurements provided by the European Space Agencys Gaia space observatorywhich are less precise than Hubbles observations in the core.

Our analysis indicated that the orbits of the stars are close to random throughout the globular cluster, rather than systematically circular or very elongated, explained Mamon. These moderate-elongation orbital shapes constrain what the inner mass must be.

Astronomers on the hunt for an intermediate-mass black hole at the heart of the globular cluster NGC 6397 found something they werent expecting: a concentration of smaller black holes lurking there instead of one massive black hole. Credit: NASA Goddard Space Flight Center

The researchers conclude that the invisible component can only be made of the remnants of massive stars (white dwarfs, neutron stars, and black holes) given its mass, extent,and location. These stellar corpses progressively sank to the clusters center after gravitational interactions with nearby less massive stars. This game of stellar pinball is called dynamical friction, where, through an exchange of momentum, heavier stars are segregated in the clusters core and lower-mass stars migrate to the clusters periphery.

We used the theory of stellar evolution to conclude that most of the extra mass we found was in the form of black holes, said Mamon. Two other recent studies had also proposed that stellar remnants, in particular, stellar-mass black holes, could populate the inner regions of globular clusters. Ours is thefirst study to provide both the mass and the extent of what appears to be a collection of mostly black holes in the center of a core-collapsed globular cluster, added Vitral.

The astronomers also note that this discovery raises the possibility that mergers of these tightly packed black holes in globular clusters may be an important source of gravitational waves, ripples through spacetime. Such phenomena could be detected by the Laser Interferometer Gravitational-Wave Observatory experiment, which is funded by the National Science Foundation and operated by Caltech in Pasadena, Californiaand MIT inCambridge, Massachusetts.

For more on this research, read Unexpected Discovery: Hubble Space Telescope Uncovers Concentration of Small Black Holes.

Reference: Does NGC 6397 contain an intermediate-mass black hole or a more diffuse inner subcluster? by Eduardo Vitral and Gary A. Mamon, 11 February 2021, Astronomy and Astrophysics.DOI: 10.1051/0004-6361/202039650

The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASAs Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.

Go here to read the rest:

Astronomers Make a Weird Discovery: A Concentration of Smaller Black Holes Lurking Where They Expected a Single Massive Black Hole - SciTechDaily

A black hole in the Cygnus X-1 binary system is so massive that it challenges current stellar evolution models.

An artists impression of the Cygnus X-1 binary system. Image credit: International Centre for Radio Astronomy Research.

Discovered in 1964, Cygnus X-1 is an X-ray binary system located in the constellation Cygnus.

The primary star, HD 226868, is a hot supergiant revolving about an unseen compact companion with a period of 5.6 days.

The companion is a so-called stellar-mass black hole, a class of black holes that comes from the collapse of a massive star.

Cygnus X-1 was the focus of a famous scientific wager between physicists Stephen Hawking and Kip Thorne, with Hawking betting in 1974 that it was not a black hole. Hawking conceded the bet in 1990.

Stars lose mass to their surrounding environment through stellar winds that blow away from their surface, said Professor Ilya Mandel, an astrophysicist at Monash University and the ARC Centre of Excellence in Gravitational Wave Discovery (OzGrav).

But to make a black hole this heavy, we need to dial down the amount of mass that bright stars lose during their lifetimes.

The black hole in the Cygnus X-1 system began life as a star approximately 60 times the mass of the Sun and collapsed tens of thousands of years ago, he added.

Incredibly, its orbiting its companion star a supergiant every five and a half days at just one-fifth of the distance between the Earth and the Sun.

Professor Mandel and colleagues observed Cygnus X-1 using the Very Long Baseline Array (VLBA).

Using the new VLBA data and archival observations, they refined the distance to the binary system and found it to be farther away than previously estimated, thus raising the inferred mass of the systems black hole to 21.2 solar masses.

Over six days we observed a full orbit of the black hole and used observations taken of the same system with the same telescope array in 2011, said Professor James Miller-Jones, an astronomer at Curtin University and the International Centre for Radio Astronomy Research (ICRAR).

This method and our new measurements show the system is further away than previously thought, with a black hole thats significantly more massive.

These new observations tell us the black hole is more than 20 times the mass of our Sun a 50% increase on previous estimates, Professor Mandel said.

Using the updated measurements for the black holes mass and its distance away from Earth, we were able to confirm that Cygnus X-1 is spinning incredibly quickly very close to the speed of light and faster than any other black hole found to date, said Xueshan Zhao, a Ph.D. candidate studying at the National Astronomical Observatories of the Chinese Academy of Sciences.

The findings were published in the journal Science.

_____

James C.A. Miller-Jones et al. Cygnus X-1 contains a 21-solar mass black hole Implications for massive star winds. Science, published online February 18, 2021; doi: 10.1126/science.abb3363

The rest is here:

Cygnus X-1's Stellar-Mass Black Hole is More Massive than Astronomers Thought | Astronomy - Sci-News.com