Category Archives: Astronomy

August Astronomy: The Month Offers Excellent Views of the Milky Way, the Perseid Meteor Shower and a Bevy of Bright Celestial Bodies  Coachella Valley Independent

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August Astronomy: The Month Offers Excellent Views of the Milky Way, the Perseid Meteor Shower and a Bevy of Bright Celestial Bodies - Coachella...

The warp in the Milky Way's spiral disk is precessing backward under the influence of the enormous mass of dark matter that forms an invisible halo around our galaxy, Chinese astronomers have discovered.

About one-third of all spiral galaxies have a distinct warp to their disk-shaped structure, like a vinyl record that has been bent. It's usually the result of a variety of factors; a collision with another galaxy in the past is believed to be the primary culprit in causing the Milky Way's warp in the first place, but further interactions with satellite galaxies and the intergalactic magnetic field, as well as the infall of vast clouds of gas, can also play their part. However, in the case of the Milky Way at least, the major player in maintaining the warp is the dark matter halo that surrounds the disk and exerts a torque on it.

This warp isn't fixed. Its alignment with the rest of the galaxy moves specifically, it "precesses." Precession describes how the alignment of the warp changes with respect to the rotational axis of the galaxy, meaning that the peak, or node, of the warp precesses around the galaxy. It's a variation of the same phenomenon that causes spinning tops to wobble.

Measuring the warp's rate of precession, however, has proven challenging in the past. Previous estimates have attempted to use the vertical motion of bright, but old, giant stars as tracers to calculate the rate of precession. However, such tracers are notoriously imprecise, and results based on them had suggested counter to theory that the disk is precessing prograde (in the same direction as the rotation of the rest of the galaxy) and not retrograde (backward with respect to the galaxy), as had been expected.

Related: What is dark matter?

Now, astronomers led by Yang Huang of the Chinese Academy of Sciences have used another, more accurate tracer in the form of Cepheid variable stars to make the most accurate measure of the warp's precession yet, finding it to be moving retrograde after all.

Cepheid variables are pulsating massive stars. Their period of pulsation is linked to how intrinsically bright they are, and based on their luminosity, we can calculate exactly how far away they must be. This makes them great tracers for mapping the warp.

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Huang's team achieved their results by way of what they call the "motion picture" method. Using data from the European Space Agency's Gaia astrometric spacecraft, which is measuring the positions, motions and properties, including the age, of more than a billion stars, Huang's team identified a sample of 2,613 Cepheids with a variety of ages.

"Age is key to measuring the precession rate of the disk warp," say the authors in their research paper. "We obtained a motion picture of the disk warp by mapping the three-dimensional distributions for Cepheid samples of different ages."

Each Cepheid retains information on its position in the warp when it was born, so by grouping the Cepheids into different age ranges and mapping them, Huang's team were able to show the shape and position of the warp at different points in time over the past 200 million years. By then running the individual maps together, like a motion picture, they were able to see the warp precessing. They found that it is precessing in retrograde fashion after all, at a rate of 2 kilometers (1.24 miles) per second for every kiloparsec (3,261 light-years) of space. Or, in more intuitive units, it is precessing backward around the galaxy by a rate of 0.12 degrees every million years.

What's more, the motion picture also shows that the precession rate decreases with distance from the galactic center, which in the long term will lead to greater warping of the disk. Models indicate that this decrease is the result of the dark matter halo that is exerting the torque being oblate, or flattened, in shape.

The shape of the dark matter halo is important because it acts as a data point that theorists can plug into models that attempt to predict what dark matter is made of (such as WIMPs or axions). It also gives clues about the formation history of the Milky Way galaxy and how it has been assembled through mergers with other, smaller galaxies and gas clouds, collisions and interactions that have helped shape the invisible dark matter halo.

The discovery of the precession rate of the warp is described in a paper published on June 27 in Nature Astronomy.

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Astronomers measure 'warp speed' of Milky Way galaxy - Space.com

Using more than 500 images from the NASA/ESA Hubble Space Telescope, astronomer have found evidence for a 20,000-solar-mass black hole at the center of Omega Centauri, a globular cluster located in the constellation of Centaurus at a distance of 5,430 parsecs (17,710 light-years) from the Sun.

Omega Centauri is about 10 times as massive as other big globular clusters. Image credit: NASA / ESA / Hubble / Maximilian Hberle, MPIA.

Astronomers know that stellar-mass black holes black holes ranging from 10 times to 100 times the Suns mass are the remnants of dying stars, and that supermassive black holes, more than 1,000,000 times the mass of the Sun, inhabit the centers of most galaxies.

But scattered across the Universe are a few apparent black holes of a more mysterious type.

Ranging from 100 to 10,000 solar masses, these intermediate-mass black holes are so hard to measure that even their existence is sometimes disputed.

Only a few intermediate-mass black hole candidates have been found to date.

Determining their population is an important step towards understanding supermassive black hole formation in the early Universe.

Omega Centauri is a special case among the globular clusters of the Milky Way, said Max Planck Institute for Astronomy astronomer Maximilian Hberle and his colleagues.

Owing to its high mass, complex stellar populations and kinematics, Omega Centauri is widely accepted as the stripped nucleus of an accreted dwarf galaxy.

These factors combined with its proximity have made it a prime target for searching for an intermediate-mass black hole.

Omega Centauri consists of roughly 10 million stars and is about 10 times as massive as other big globular clusters.

In their study, the authors measured the velocities for 1.4 million stars gleaned from the Hubble images of the cluster.

Most of these observations were intended to calibrate Hubbles instruments rather than for scientific use, but they turned out to be an ideal database for the teams research efforts.

We searched for fast-moving stars expected to exist near concentrated masses, like black holes, said University of Queensland astronomer Holger Baumgardt.

Identifying these stars was the smoking gun evidence we needed to prove the black holes existence, and we did.

We discovered seven stars that should not be there, Dr. Hberle said.

They are moving so fast that they would escape the cluster and never come back.

The most likely explanation is that a very massive object is gravitationally pulling on these stars and keeping them close to the center.

The only object that can be so massive is a black hole, with a mass at least 8,200 times that of our Sun.

This discovery is the most direct evidence so far of an intermediate-mass black hole in Omega Centauri, said Dr. Nadine Neumayer, an astronomer at the Max Planck Institute for Astronomy.

This is exciting because there are only very few other black holes known with a similar mass.

The black hole in Omega Centauri may be the best example of an intermediate-mass black hole in our cosmic neighborhood.

The teams paper was published in the journal Nature.

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M. Hberle et al. 2024. Fast-moving stars around an intermediate-mass black hole in Centauri. Nature 631, 285-288; doi: 10.1038/s41586-024-07511-z

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Astronomers Find Intermediate-Mass Black Hole in Milky Ways Most Massive Globular Cluster - Sci.News

UNIVERSITY PARK, Pa. Penn States 2020 Philanthropist of the Year, Keiko Miwa Ross, has directed over $17 million in support to landmarks across University Park, from the Dr. Keiko Miwa Ross Student Farm to the spaces that welcome visitors to the new Palmer Museum of Art. Now her philanthropy is reaching beyond the Penn State campus to shape our understanding of the universe with a $2 million commitment to endow the Lee M. Hammarstrom-Dr. Keiko Miwa Ross Endowed Faculty Position in the Department of Astronomy and Astrophysics.

The gift honors Ross' friendship with Lee Hammarstrom, a Penn State engineering alumnus and a pioneer in intelligence space systems, and it will support the work of Joel Leja, an assistant professor of astronomy and astrophysics whose work explores the formation of distant galaxies.

Dr. Rosss extraordinary generosity in support of our students and our mission has already enriched our campus and community in so many ways, for which I am profoundly grateful. This latest commitment will build on her incredible impact by enhancing Penn States leadership in astronomy and astrophysics while supporting the work of researchers and educators like Dr. Leja, said Penn State President Neeli Bendapudi. Penn States exceptional faculty drive innovation and impact while bringing a world-class education to our students, and the new Lee M. Hammarstrom-Dr. Keiko Miwa Ross Endowed Faculty Position will enhance our ability to recruit and retain leading experts and scholars ensuring that the Penn State name, as well as those of Dr. Ross and Mr. Hammarstrom, remains synonymous with excellence and discovery.

The endowment will empower the Department of Astronomy and Astrophysics to award support to a faculty member at any stage of their career, helping to recruit and retain both established leaders and emerging stars.

Private support is crucial to enhancing the positive impact of our facultys work as well as fulfilling the Universitys critically important mission as Pennsylvanias land-grant institution, said Tracy Langkilde, Penn State interim executive vice president and provost, and the Verne M. Willaman Dean of the Eberly College of Science. Dr. Rosss philanthropy has touched almost every part of this University, including support for the arts, innovation and entrepreneurship and student success. We are especially humbled that she has chosen the Eberly College of Science for her first faculty endowment.

Langkildes gratitude is shared by Mary Beth Williams, acting dean of the Eberly College of Science. Williams said, This extraordinary commitment will support faculty in our college who are advancing the frontiers of scientific knowledge. Through Mr. Hammarstroms inspiration and advocacy, Dr. Ross recognized the exceptional research being conducted in the Department of Astronomy and Astrophysics and structured her unique financial support to be both immediate and flexible to meet the research needs of our faculty as they expandhuman understanding of the universe. This is truly a special and impactful gift, and we are grateful to both Dr. Ross and Mr. Hammarstrom.

Ross and Hammarstrom are both residents of the Village at Penn State in State College. Born and raised in Japan, Ross was an educational pioneer in her native country, one of the nations first female undergraduates. She completed her education in the United States, first receiving her bachelor of arts degree and, later, her masters and doctoral degrees in education from universities in Washington State. Through her work, she met S. Thomas Ross, director of an American-Japanese joint venture company. They met in 1970, were married the following year and lived in Japan until 1977, when Thomas was assigned to New York. Keiko subsequently became an American citizen and worked for the U.S. Department of State. The Rosses ultimately settled in State College, and Thomas passed away in 2013.

Supporting Penn State has given me a path to continuing my lifelong commitment to education and excellence, said Ross. The University Park campus is both an extraordinary place for learning, discovery and service to the community and a home for extraordinary faculty and students. I am pleased to extend my philanthropy in support of Dr. Joel Leja and the Department of Astronomy and Astrophysics because I believe that they have the potential to change human understanding and carry Penn States impact forward far into the future.

Lee M. Hammarstrom earned a degree in electrical engineering from Penn State in 1962 and went on a long career in space and information technology, eventually serving as a special assistant to the director of the Applied Research Laboratory (ARL) at his alma mater. Working at the Naval Research Laboratory (NRL), he conceived and led a satellite reconnaissance program, named PARCAE, that President Ronald Reagan recognized twice for its contributions to national security. He was the system engineer and integrator for the initial GPS program that demonstrated the navigation capacities the world enjoys today. He created the National Reconnaissance Offices (NRO) Technology Office and became the first chief scientist at the NRO. He conceived and led a Department of Defense wide communications network upgrade that improved world-wide secure communications by 42 times from Desert Storm 1 in 1991, to Desert Storm 2 in 2003. Hammarstrom was named an NRO Pioneer in 2002 for his 40 years of contributions to national reconnaissance. He said he credits Penn States cross-disciplinary environment for his successes.

Over my career, I have had the privilege of working alongside some of the most visionary scientists in my field, and I am excited that Penn State has become a home to the next generation of extraordinary leaders in astronomy and astrophysics, said Hammarstrom. Dr. Joel Leja in particular is a researcher whose work has the potential to fundamentally change our understanding of the universe. To keep individuals of his caliber at Penn State, we must invest in their future careers. I am delighted that Dr. Ross has stepped forward with this commitment, and I am honored to have my name linked with hers and with that of Dr. Leja.

As the first holder of the Lee M. Hammarstrom-Dr. Keiko Miwa Ross Endowed Faculty Position, Leja will use the endowments support to further his analysis of the first very deep surveys with the James Webb Space Telescope, discovering and characterizing galaxies formed in the first few billion years of the Universe.Access to the data gathered by the telescope has helped Leja to investigate the brightest gamma-ray burst ever recorded and its potential as a birthplace for heavy elements, some of the earliest starlight in the universe and evidence of massive galaxies dating back more than 13 billion years.

As the author or co-author of over a hundred scientific papers in journals such as the Astrophysical Journal, Monthly Notices of the Royal Astronomical Society, and Nature, Leja was named a Clarivate Highly Cited Researcher in 2023, honoring those in the top 1% of cited researchers in astrophysics. He was awarded Yale University's Brouwer Prize in 2019 for a doctoral thesis of unusual merit. Prior to joining the faculty at Penn State, Leja was a postdoctoral researcher at the Center for Astrophysics of Harvard University and the Smithsonian.

I am truly grateful for this generous gift and the impact it will have on our mission of research, education and outreach in the Department of Astronomy and Astrophysics and the Eberly College of Science, and at Penn State, said Leja. Lee and I first connected at the colleges Ashtekar Frontiers of Science Lectures, and I am glad that this public outreach effort helped to draw attention to the work that is happening at Penn State. The universe is the worlds biggest laboratory, both awesome and inspiring, and this support will help us continue pushing the bounds of knowledge.

Gifts like the Lee M. Hammarstrom-Dr. Keiko Miwa Ross Endowed Faculty Position advance the Universitys historic land-grant mission to serve and lead. Through philanthropy, alumni and friends are helping students to join the Penn State family and prepare for lifelong success; driving research, outreach and economic development that grow our shared strength and readiness for the future; and increasing the Universitys impact for families, patients and communities across the commonwealth and around the world. Learn more by visiting raise.psu.edu.

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New faculty endowment in astronomy and astrophysics created by Keiko Miwa Ross - Penn State University

Credit: NASA/JPL-Caltech

Scientists have long wondered why more bowl-shaped craters from asteroid strikes havent been found on Mars, despite the Red Planet sitting next to the asteroid belt and its sparse atmosphere being just 1 percent as thick as Earths. A new study suggests roughly 300 basketball-sized meteorites pockmark Mars surface every year, raising previous estimates by five times.

The findings are based on data from NASAs InSight lander, which for over four years listened to Mars seismic shakes and probed the planets geological history. The researchers studied seismological data recorded by InSights onboard seismometer, which scientists say is capable of hearing the slightest rumbles on Mars. They found that there isnt a place on Mars that is more likely to be hit than any other place, says study lead author Natalia Wjcicka of the Imperial College London, adding that future robotic and crewed missions to Mars could benefit from these findings while selecting landing spots and base camps.

The new impact rate is five times higher than estimates published a decade ago and based on satellite images, rather than on-the-ground data. That suggests that we miss a lot of craters by just looking at the surface of the planet because we dont image all of Mars all the time, says Wjcicka.

Moreover, many craters left behind by such impacts have never been seen by orbiting satellites, the researchers found. We were certainly very excited, says Wjcicka. We almost didnt believe it.

The seismometer onboard InSight, called the Seismic Experiment for Interior Structure, or SEIS, recorded about 1,300 marsquakes during its four-year mission. The instrument by itself wasnt able to distinguish which rumbles were due to meteorites, or where on Mars they occurred. But a group of signals share similar properties, key of which is that most of their energy is above 4 hertz, consistent with a shallow source like a meteorite strike rather than a quake deep within Mars, says Wjcicka.

Between 2018 to 2022, InSight heard 70 so-called very high-frequency events, all of which were likely created by meteorite crashes, according to the new study, which was published last month in Nature Astronomy.

By studying the properties of these signals, Wjcicka and her team predict between 280 and 360 basketball-sized meteorites land across Mars each year and leave behind craters bigger than 26 feet (8 meters) in diameter. Although this crater size is within the range scientists can spot in satellite images, we dont have a systematic way that we take images of areas, says Wjcicka, so its difficult to associate craters with the events InSight heard. But [the signals] are similar enough to each other that at least more if not all of them could be impact related, but we dont have confirmation of that because we havent seen the craters.

Satellites dont capture all of Mars all the time, and often there arent repetitive images of the same region. This limits the amount of comparison scientists can do of a region before a meteorite strike versus after, when the crater or any material excavated by the meteorite could be spotted in images. The task is made harder by the fact that sifting through the images almost always requires a human eye, says Wjcicka.

It does take a lot of training from the human side to find those craters in the images, she says. The smaller it gets, the more youre likely to miss it.

Last month, a different team of scientists spotted eight football field-sized impact craters puncturing Mars surface that were not previously seen by satellites. Six were near InSights landing spot and two were among the largest ever spotted, suggesting the planet is getting hit much more frequently than we can see using imaging alone, Ingrid Daubar of Brown University in Rhode Island, who led the companion study, said in a statement.

Impacts this large are expected to occur only every few decades, perhaps even just once in a lifetime, Daubar said. But his team found they had occurred just 97 days apart. It could just be a crazy coincidence, but theres a really, really small likelihood that its just coincidence, he said. Whats more likely is that either the two big impacts are related, or the impact rate is a lot higher for Mars than what we thought it was.

Unlike Earth, Mars lacks active plate tectonics, the continually shifting chunks of crust that trigger earthquakes when they grind together. The planet rumbles from deep within nonetheless, primarily driven by the world shrinking and cooling

Conventionally, scientists use the number of craters as cosmic clocks to date a planets surface, with older surfaces pockmarked with more craters than younger ones. Because higher impact rates mean less time is needed to accumulate the same number of craters, better constraints of impact rates can help scientists fine-tune their gauges of how old the martian surface is. This, in turn, can reveal when the last major event that erased previous craters, such as a volcanic eruption, occurred on Mars.

And if the impact rate on Mars is different than thought, this is going to require us to rethink some of the models the science community uses to estimate the age of planetary surfaces throughout the entire solar system, Daubar said. And by understanding what happened on Mars, scientists can better understand the history of our own planet, he added.

This is important for understanding our solar system, whats in it and what the population of impacting bodies in our solar system looks like both as hazards to the Earth and also historically to other planets, said Daubar.

Related: Probe counts space rock impacts on Mars

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Mars is bombarded by more meteorites than previously thought - Astronomy Magazine

Every year, Greenwichs Royal Observatory considers photos of the cosmos for its Astronomy Photographer of the Year competition. The 16th rendition of the contest does not disappoint. From distant spinning galaxies to brilliant auroras on our very own planet, the entrants in this years competition show off everything the heavens have to offer.

If youre in the London area, you can see the shortlisted photos in person at the National Maritime Museum in Greenwich. But if youre not, you can check out the shortlisted finalists below.

The starbursts of color are the Geminid meteor shower as seen from La Palma, one of the Canary Islands. The Milky Way also appears in the background.

The galaxy NGC 6744 sits 30 million light-years from Earth, and resembles how our own galaxy would look from such a distance.

A beautiful combination of pinks, yellows, and greens illuminate the sky over Icelands Eystrahorn Mountain during a geomagnetic storm in December 2024.

This strikingly detailed image reveals the Suns surface. Towards the top left quarter of the Sun, a plasma filament that looks a bit like a whale swims across the stars surface.

An abandoned home in Namibias Namib Desert, with the Milky Way hanging above it, presents a stunning contrast. The shot reminds me a bit of the landscapes in Courage the Cowardly Doganyone else?

These rock formations are located in a caldera in the Canary Islands Teide National Park. Behind the formations is the arc of the Milky Way.

Per the title, the aurora above Icelands Arctic Henge resembles a bright green dragon.

The deep reds of the Aurora Australis beneath the arc of the Milky Way, as seen from New Zealands Castle Hill.

This trippy shot captures the reflection of light from various sources across the night sky, reflected in some of the 12,000 mirrors at a power station in China.

A volcanic crater in Japan, the Milky Way above it.

This filamentous blue structure is a part of the Vela supernova, which exploded roughly 11,000 years ago.

Octobers full moon is also called a Hunters Moon. In the foreground of the natural satellite is the International Space Station (bottom right).

A galaxy 11.75 million light-years away, sitting in the constellation Ursa Major.

The dwarf planet Ceres is seen here as four bright spots, transiting in front of the Blowdryer Galaxy (formally M100).

This eerie shot of a supernova afterglow gets its name from Edvard Munchs The Scream; indeed, the stellar remnants resemble a howling person.

The Pelican Nebulas dust and gas structures, seen through a telescope in Hungary.

The Martian landscape as seen by the Mars Reconnaissance Orbiter. The image abstracts the landscape to the point that the terrain looks like a chunk of some menacing creature.

A spellbinding shot of the Isaac Newton Telescope in the Canary Islands, with the Cygnus region of the Milky Way visible at top right.

This captivating photo from Namibia features a stone sculpture of a person in mid-stride.The Carina Nebulawhich the Webb Space Telescope imaged as one of its first science targetsis visible top right.

Behold Saturn, the ringed planet, accompanied by six of its moons. To the left, you can spot Rhea, Enceladus, and Mimas as tiny specks. Dione is visible at the bottom right, Titan at the top right, and Tethys is just about to disappear behind Saturn itself.

These are the remains of a jetty on Norfolks Snettisham Beach, under a long exposure of the stars in the night sky.

A sunspot is shown here erupting on the surface of the Sun. Sunspots are darker regions on the Suns surface associated with the stars magnetic field.

The luminous blue lights of the Pleiades, as seen from Nerpio, Spain.

Jupiter with its moons Io and Ganymede. Io is a compelling research target for scientists, given its desolate and volcano-covered landscape.

Heres another aurora reminiscent of a mythical flying serpent. This photo is in black and white, an interesting approach to one of the most famously vibrant natural phenomena on Earth.

This ominous shot portends doom for a galaxy (top left), threatened by CG4, a giant cloud of gas and dust in space.

This image, captured using a telescope at Chiles El Sauce Observatory, shows the incredibly flat M104, or Sombrero Galaxy, including the dust that permeates the object.

A composite image showing the transit of the ISS across the face of the Moon.

An iridescent rainbow of the Suns corona as it appears in altostratus clouds above the Himalayan mountains.

An arguably obligatory image of a total solar eclipse. This one was captured in Australia in April 2023; the image is made of seven superimposed photos that capture different states of the eclipse.

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These Shortlisted Images From Astronomy Photographer of the Year Are Pure Fire - Gizmodo

Enjoy a watch party tonight

Kick off the latest season of The Bachelorette with friends tonight, Monday, July 8, at Pelican to Mars.

The Mid City bar will host its first Bachelorette Watch Party of season 21. Enjoy a free glass of prosecco while crafting your Bachelorette bracket, and come back each week to see who Jenna Tran, the ABC shows first Asian American lead, gives a rose.

The Bachelorette Watch Party is from 6:30-9:30 p.m. and is free to attend. Pelican to Mars is at 2678 Government St. Find more information here.

Head over to Nicholson Hall on Tuesday, July 9, to experience Astronomy Night at LSU.

Attendees can enjoy Einstein surfing black hole waves presented by Gabriela Gonzlez, LSUs Boyd Professor of Physics. The event will also include physics demos, an astronomy viewing from the Landolt Astronomical Observatory and ice cream.

Astronomy Night is from 5:30-10 p.m. It is free and open to all ages. This event will take place in 130 Nicholson Hall on LSUs campus. Contact Outreach Coordinator Olivia Crowell at the Department of Physics and Astronomy at LSU at 225-578-2261 or email [emailprotected] with questions. Find more information here.

Head to La Divina Italian Cafe on Wednesday, July 10, for an art reception celebrating art from St. James Place.

Guests can enjoy live music by Jeff Bajon along with select wines, ice-cold beer and hors doeuvres while chatting with the featured artists about their work. Featured artists include Dr. June Tuma, Betty Falgout and Audrey Walker.

The Art of St. James Place is from 6-8 p.m. This event is free and open to the public. La Divina Italian Cafe is at 3535 Perkins Road, Unit 360. Find more information here.

Jam out with local acts when Chelseas Live brings back The Stew, this Thursday, July 11.

The local music showcase will feature singer-songwriter McKenzie Knapps, metal band Pauldron, Rhinoceros and Libson Girls. Rock artist Cody Riker will headline the event and celebrate his latest album 4REAL.

Doors open at 7 p.m. and the show begins at 8 p.m. Tickets are $10 in advance and $15 at the door. This show is for those ages 18 and up. Chelseas Live is at 1010 Nicholson Drive. Find more information here.

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This week in Baton Rouge: Astronomy Night, Bachelorette watch party, local music and more - 225 Baton Rouge

Join in for a free event, Astronomy in the Park, on Saturday, July 13 at Shumway Oak Grove Regional Park, I-5 at Eight Mile Road, Stockton. The program is presented by The Stockton Astronomical Society, Oak Grove Docent Council, and San Joaquin County Parks.

View planets through giant telescopes after sunset. The July 13 program starts at 8:30 p.m. and features Mercury and M3, Star Cluster in Canes Venatici. There is no charge for the program but there is a $6 cash parking fee at the park.

Also, prior to the viewing, enjoy astronomy activities at the Nature Center until 8 p.m.

For more information, call 209-953-8814 or 209-953-8800.

Upcoming shows will feature: Aug. 10, 8 p.m., M8 and M20 (Lagoon Nebula, Trifid Nebula); Sept. 7, 7:25 p.m., Saturn, M13 (Star Cluster) and M57 (Ring Nebula). On Oct. 12, view Star Cluster in Hercules and the Dumbbell Nebula at 6:30 p.m.; Nov. 9 at 5 p.m., see Jupiter, Saturn, Venus and M31 (Andromeda Galaxy); Dec. 7, 4:45 p.m., see Saturn, Mars, M33 (Triangulum Galaxy).

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Astronomy Nights return to Oak Grove - Riverbank News

Omega Centauri is a spectacular collection of 10 million stars, visible as a smudge in the night sky from Southern latitudes. Through a small telescope, it looks no different from other so-called globular clusters; a spherical stellar collection so dense towards the center that it becomes impossible to distinguish individual stars. But a new study, led by researchers from the University of Utah and the Max Planck Institute for Astronomy, confirms what astronomers had argued about for over a decade: Omega Centauri contains a central black hole. The black hole appears to be the missing link between its stellar and supermassive kinstuck in an intermediate stage of evolution, it is considerably less massive than typical black holes in the centers of galaxies. Omega Centauri seems to be the core of a small, separate galaxy whose evolution was cut short when it was swallowed by the Milky Way.

This is a once-in-a-career kind of finding. Ive been excited about it for nine straight months. Every time I think about it, I have a hard time sleeping, said Anil Seth, associate professor of astronomy at the U and co-principal investigator (PI) of the study. I think that extraordinary claims require extraordinary evidence. This is really, truly extraordinary evidence.

A clear detection of this black hole had eluded astronomers until now. The overall motions of the stars in the cluster showed that there was likely some unseen mass near its center, but it was unclear if this was an intermediate-mass black hole or just a collection of the stellar black holes. Maybe there was no central black hole at all.

Previous studies had prompted critical questions of So where are the high-speed stars? We now have an answer to that, and the confirmation that Omega Centauri contains an intermediate-mass black hole. At about 18,000 light-years, this is the closest known example for a massive black hole, said Nadine Neumayer, a group leader at the Max Planck Institute and PI of the study. For comparison, the supermassive black hole in the center of the Milky Way is about 27,000 light-years away.

Thepaperwas published in the journal Nature on July 11, 2024. Watch the research come to life on August 8, 2024, at 7:00 p.m. when Anil Seth will present these once-in-a-lifetime findings at the Clarke Planetarium IMAX theater.

A range of black hole masses

In astronomy, black holes come in different mass ranges. Stellar black holes, between one and a few dozen solar masses, are well known, as are the supermassive black holes with masses of millions or even billions of suns. Our current picture of galaxy evolution suggests that the earliest galaxies should have had intermediate-sized central black holes that would have grown over time, gobbling up smaller galaxies done or merging with larger galaxies.

Such medium-sized black holes are notoriously hard to find. Although there are promising candidates,there has been no definite detection of such an intermediate-mass black holeuntil now.

There are black holes a little heavier than our sun that are like ants or spiderstheyre hard to spot, but kind of everywhere throughout the universe. Then youve got supermassive black holes that are like Godzilla in the centers of galaxies tearing things up, and we can see them easily, said Matthew Whittaker, an undergraduate student at the U and co-author of the study. Then these intermediate-mass black holes are kind of on the level of Bigfoot. Spotting them is like finding the first evidence for Bigfootpeople are going to freak out.

Needle in an archival haystack

When Seth and Neumayer designed a research project to better understand the formation history of Omega Centauri in 2019, they realized they could settle the question of the clusters central black hole once and for all. If they found fast-moving stars around its center, they would have the proverbial smoking gun, as well as a way of measuring the black holes mass.

The arduous search became the task ofMaximilian Hberle, a doctoral student at the Max Planck Institute. Hberle led the work of creating an enormous catalogue for the motions of stars in Omega Centauri, measuring the velocities for 1.4 million stars by studying over 500 Hubble images of the cluster. Most of these images had been produced for the purpose of calibrating Hubbles instruments rather than for scientific use. But with their ever-repeating views of Omega Centauri, they turned out to be the ideal data set for the teams research efforts.

Looking for high-speed stars and documenting their motion was the proverbial search for a needle in a haystack, Hberle said. In the end, Hberle not only had themost complete catalogof the motion of stars in Omega Centauri yet, he also found seven needles in his archival haystackseven tell-tale, fast-moving stars in a small region in the center of Omega Centauri.

Uncovering a black hole

The seven stars move fast because of the presence of a concentrated nearby mass. For a single star, it would be impossible to tell whether it is fast because the central mass is large or because the star is very close to the central massor if the star is merely flying straight, with no mass in sight. But seven such stars, with different speeds and directions of motion, allowed the team to separate the different effects and determine that thereisa central mass in Omega Centauri, with the mass of at least 8,200 suns. The images do not indicate any visible object at the inferred location of that central mass, as one would expect for a black hole.

The broader analysis also allowed the team to narrow down the location of Omega Centauris central region at 3 light-months in diameter (on images, 3 arc seconds). In addition, the analysis provided statistical reassurance: A single high-speed star in the image might not even belong to Omega Centauri. It could be a star outside the cluster that passes right behind or in front of Omega Centauris center by chance. The observations of seven such stars, on the other hand, cannot be pure coincidence, and leaves no room for explanations other than a black hole.

An intermediate-mass black hole at last

Given their findings, the team now plans to examine the center of Omega Centauri in even more detail. The Us Seth is leading a project has gained approval to use the James Webb Space Telescope for measuring the high-speed stars movement towards or away from Earth, and there are future instruments (GRAVITY+ at ESOs VLT, MICADO at the Extremely Large Telescope) that could pinpoint stellar positions even more accurately than Hubble. The long-term goal is to determine how the stars accelerate: how their orbits curve. Following those stars once around their whole orbit, as in the Nobel-prize-winning observations near the black hole in the center of the Milky Way, is a project for future generations of astronomers, though. The smaller black hole mass for Omega Centauri means ten times larger time scales than for the Milky Way: orbital periods of more than a hundred years.

Background information The work described here has been published as M. Hberle et al., Fast-moving stars around an intermediate-mass black hole in Centauri in the journal Nature. The star catalog on which the work is based has been accepted for publication as M. Hberle et al., oMEGACat IIPhotometry and proper motions for 1.4 million starsin Omega Centauri and its rotation in the plane of the sky in the Astrophysical Journal.

Other authors include the Max Plank Institute of Astronomy researchers Antoine Dumont, Callie Clontz (also University of Utah), Anja Feldmeier-Krause (also University of Vienna) and Maria Selina Nitschai in collaboration with Andrea Bellini (Space Telescope Science Institute), Mattia Libralato (ESA and INAF Padova), Holger Baumgardt (The University of Queensland), Mayte Alfaro Cuello (Universidad Central de Chile), Jay Anderson (Space Telescope Science Institute), Nikolay Kacharov (Leibniz Institute for Astrophysics Potsdam), Sebastian Kamann (Liverpool John Moores University), Antonino Milone (University of Padova), Renuka Pechetti (Liverpool John Moores University) and Glenn van de Ven (University of Vienna).

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Astronomers find missing link in massive black hole formation - ScienceBlog.com

The SpaceX Crew Dragon Freedom splashed down with four astronauts on October 14, 2022. Credit: NASA/u003c/strongu003e

For about 15 minutes on July 21, 1961, American astronautGus Grissomfelt at the top of the world and indeed he was.

Grissom crewed theLiberty Bell 7 mission, a ballistic test flight that launched him through the atmosphere from a rocket. During the test, he sat inside a small capsule and reached a peak of over 100 miles up before splashing down in the Atlantic Ocean.

A Navy ship, the USS Randolph, watched the successful end of the mission from a safe distance. Everything had gone according to plan, the controllers at Cape Canaveral were exultant, and Grissom knew he had just entered a VIP club as the second American astronaut in history.

Grissom remained inside his capsule and swayed on the gentle ocean waves. While he waited for a helicopter to take him onto the USS Randolphs dry deck, he finished recording some flight data. But then, things took an unexpected turn. An incorrect command in the capsules explosives system causedthe hatch to pop out, which let water flow into the tiny space. Grissom had also forgotten to close a valve in his spacesuit, so water began to seep into his suit as he fought to stay afloat.

After a dramatic escape from the capsule, he struggled to keep his head above the surface while giving signals to the helicopter pilot that something had gone wrong. The helicopter managed to save him at the last instant. Grissoms near-death escape remains one of the most dramatic splashdowns in history. But splashing down into water remains one of the most common ways astronauts return to Earth. I am aprofessor of aerospace engineeringwho studies the mechanisms involved in these phenomena. Fortunately, most splashdowns are not quite that nerve-racking, at least on paper.

Before it can perform a safe landing, a spacecraft returning to Earthneeds to slow down. While it is careening back to Earth, a spacecraft has a lot of kinetic energy. Friction with the atmosphere introduces drag, which slows down the spacecraft. The friction converts the spacecrafts kinetic energy to thermal energy, or heat.

All this heat radiates out into the surrounding air, which gets really, really hot. Since reentry velocities can be several times the speed of sound, the force of the air pushing back against the vehicle turns the vehicles surroundings into a scorching flow thats about 2,700 degrees Fahrenheit (1,500 degrees Celsius). In the case ofSpaceXs massive Starship rocket, this temperature even reaches3,000 degrees Fahrenheit (nearly 1,700 degrees Celsius).

Unfortunately, no matter how quickly this transfer happens, theres still not enough time during reentry for the vehicle to slow down to a safe enough velocity not to crash. So, the engineers resort to other methods that can slow down a spacecraft during splashdown.

Parachutes are the first option. NASA typically uses designs with bright colors, such as orange, which make them easy to spot. Theyre also huge, with diameters of over 100 feet, and each reentry vehicle usually uses more than one for the best stability. The first parachutes deployed, called drag parachutes, eject when the vehicles velocity falls below about 2,300 feet per second (700 meters per second).

Even then, the rocket cant crash against a hard surface. It needs to land somewhere that will cushion the impact. Researchers figured out early on that water makes an excellent shock absorber. Thus, splashdown was born.

Water has a relatively low viscosity that is, it deforms fast under stress and it has a density much lower than hard rock. These two qualities make it ideal for landing spacecraft. But the other main reason water works so well is because it covers 70% of the planets surface, so the chances of hitting it are high when youre falling from space.

The science behind splashdown is complex, asa long history proves.

In 1961, the U.S. conducted the first crewed splashdowns in history. These usedMercury reentry capsules.

These capsules had a roughly conical shape and fell with the base toward the water. The astronaut inside sat facing upward. The base absorbed most of the heat, so researchers designed a heat shield that boiled away as the capsule shot through the atmosphere.

As the capsule slowed and the friction reduced, the air got cooler, which made it able to absorb the excess heat on the vehicle, thereby cooling it down as well. At a sufficiently low speed, the parachutes would deploy.

Splashdown occurs at a velocity of about80 feet per second (24 meters per second). Its not exactly a smooth impact, but thats slow enough for the capsule to thwack into the ocean and absorb shock from the impact without damaging its structure, its payload or any astronauts inside.

Followingthe Challenger loss in 1986, when the space shuttle Challenger broke apart shortly after liftoff, engineers started focusing their vehicle designs on whats called thecrashworthiness phenomena or the degree of damage a craft takes after it hits a surface.

Now, all vehicles need to prove that they can offer a chance of survival on water after returning from space. Researchers build complex models, then test them with laboratory experiments to prove that the structure is sturdy enough to meet this requirement.

Between 2021 and June 2024, sevenof SpaceXs Dragon capsules performed flawless splashdowns on their return from the International Space Station.

On June 6, the most powerful rocket to date,SpaceXs Starship, made a phenomenal vertical splashdown into the Indian Ocean. Its rocket boosters kept firing while approaching the surface, creating an extraordinary cloud of hissing steam surrounding the nozzles.

SpaceX has been using splashdowns to recover the Dragon capsulesafter launch, with no significant damage to their critical parts, so that it can recycle them for future missions. Unlocking this reusability will allow private companies to save millions of dollars in infrastructure and reduce mission costs.

Splashdown continues to be the most common spacecraft reentry tactic, and with more space agencies and private companies shooting for the stars, were likely to see plenty more take place in the future.

This article is republished fromThe Conversationunder a Creative Commons license. Read theoriginal article.

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Heres how astronauts splash back to Earth - Astronomy Magazine