astronomy (28)

J0030...

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The pulsar J0030 appears to have two to three hotspots on its southern hemisphere only – finding astronomers didn’t expect.
NASA’s Goddard Space Flight Center/CI Lab
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Topics: Astronomy, Astrophysics, NASA, Neutron Stars, Pulsars

NASA’s NICER instrument reveals that neutron stars are not as simple as we thought.

Pulsars are the lighthouses of the universe. These tiny, compact objects are neutron stars — the remnants of once-massive stars — that spin rapidly, beaming radiation into space. Now, for the first time, astronomers have mapped the surface of a 16-mile-wide pulsar in exquisite detail. The discovery calls into question astronomers’ textbook depiction of pulsar appearance and opens the door to learning more about these extreme objects.

The Neutron star Interior Composition Explorer, or NICER, searches for X-rays from extreme astronomical objects such as pulsars from its perch on the exterior of the International Space Station. Researchers used NICER to observe the pulsar J0030+0451, or J0030 for short, which is located 1,100 light-years away in the constellation Pisces, in a series of papers published in The Astrophysical Journal Letters. Two teams, one led by researchers at the University of Amsterdam and the other by researchers at the University of Maryland, used X-ray light from J0030 to map the pulsar’s surface and calculate its mass. Both teams arrived at a conclusion that was unexpected.

A New Picture

What the teams found presented a different picture: J0030 has two or three hotspots, all of which are located in the southern hemisphere. The researchers at the University of Amsterdam believe the pulsar has one small, circular spot and one thin, crescent-shaped spot spinning around its lower latitudes. The University of Maryland team discovered that the X-rays could be coming from two oval spots in the star’s southern hemisphere, as well as one cooler spot near the star’s south pole.

Neither result is the simple picture astronomers expected, indicating that the pulsar’s magnetic field, which causes the hotspots, is likely even more complex than originally assumed. While the result certainly leaves astronomers wondering, “It tells us NICER is on the right path to help us answer an enduring question in astrophysics: What form does matter take in the ultra-dense cores of neutron stars?” NICER science lead and study co-author Zaven Arzoumanian said in a press release.

Astronomers Map a Neutron Star’s Surface for the First Time, Ignat, I Love the Universe

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Yonder Water Worlds...

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Hot and humid The surface of a Hycean planet as interpreted by an artist. (Courtesy: Amanda Smith, University of Cambridge).

Topics: Astronomy, Astrophysics, Astrobiology, Exoplanets, Space Exploration

Hot, ocean-covered exoplanets with hydrogen-rich atmospheres could harbor life and may be more common than planets that are Earth-like in size, temperature, and atmospheric composition. According to astronomers at the University of Cambridge, UK, this newly defined class of exoplanets could boost the search for life elsewhere in the universe by broadening the search criteria and redefining which biosignatures are important.

Astronomers define the habitable or “Goldilocks” zone as the region where an exoplanet is neither too close nor too far from its host star to have liquid water on its surface – water being the perfect solvent for many forms of life. Previous studies of planetary habitability have focused primarily on searching for Earth-like exoplanets and evidence that they could harbor the kind of chemistry found in life on Earth. However, it has so far proven difficult to detect atmospheric signatures from Earth-like planets orbiting Sun-like stars.

Potentially habitable mini-Neptunes

Larger exoplanets are easier to detect than smaller, Earth-sized ones, and exoplanets around 1.6‒4 times bigger than the Earth, with masses of up to 15 Earth masses and temperatures that in some cases exceed 2000 K, are relatively common. These planets are known as mini-Neptune's as they are similar to the ice giant planets in our solar system.

Previous studies suggested that the high pressures and temperatures beneath these planets’ hydrogen-rich atmospheres were incompatible with life. However, based on their analysis of an exoplanet called K2-18b, exoplanet scientist Nikku Madhusudhan and colleagues at Cambridge say that life could, in fact, exist on a subset of mini-Neptunes that meet specific criteria.

This subset, which the researchers dub “Hycean” (hydrogen + ocean) planets, consists of planets that have radii up to 2.6 times larger than Earth’s and are capable of harboring vast oceans under atmospheres dominated by molecular hydrogen and water vapor. Such oceans could cover the whole planet and reach depths greater than the Earth’s oceans, and the researchers say that the conditions within them could be compatible with some forms of Earth-based microbial life. Hycean planets tidally locked with their host star could also exhibit habitable conditions on their permanent night side.

Astronomers define new class of potentially habitable ocean worlds, Chaneil James, Physics World

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Ganymede...

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A global view of Ganymede, based on data gathered by NASA’s Voyager 1, Voyager 2, and Galileo spacecraft. Credit: USGS Astrogeology Science Center, Wheaton, NASA and JPL-Caltech

Topics: Astronomy, Astrophysics, NASA, Planetary Science, Space Exploration

Ganymede, get ready for your close-up.

No probe has gotten a good view of Jupiter’s largest moon since 2000 when NASA’s Galileo spacecraft swung past the strange world, which is the largest moon in the whole solar system. But on Monday (June 7),  at 1:35 p.m. EDT (1735 GMT), NASA’s Juno spacecraft will skim just 645 miles (1,038 kilometers) above Ganymede’s surface, gathering a host of observations as it does so.

“Juno carries a suite of sensitive instruments capable of seeing Ganymede in ways never before possible," principal investigator Scott Bolton, a space scientist at the Southwest Research Institute in San Antonio, said in a NASA statement. “By flying so close, we will bring the exploration of Ganymede into the 21st century.”

Ganymede is a fascinating world for scientists. Despite its status as a moon, it’s larger than the tiny planet Mercury and is the only moon to sport a magnetic field, a bubble of charged particles dubbed a magnetosphere. Until now, the only spacecraft to get a good look at Ganymede were NASA’s twin Voyager probes in 1979 and the Galileo spacecraft, which flew past the moon in 2000.

NASA’s Juno Set for Close Encounter with Jupiter’s Moon Ganymede, Meghan Bartels, SPACE.com, Scientific American

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Sun Quake...

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The first coronal mass ejection, or CME, observed by the Solar Orbiter Heliospheric Imager (SoloHI) appears as a sudden gust of white (the dense front from the CME) that expands into the solar wind. This video uses different images, created by subtracting the pixels of the previous image from the current image to highlight changes. The missing spot in the image on the far right is an overexposed area where light from the spacecraft solar array is reflected into SoloHI’s view. The little black and white boxes that blip into view are telemetry blocks – an artifact from compressing the image and sending it back down to Earth.
Credits: ESA & NASA/Solar Orbiter/SoloHI team/NRL

Topics: Astronomy, Astrophysics, ESA, Heliophysics, NASA

For the new Sun-watching spacecraft, the first solar eruption is always special.

On February 12, 2021, a little more than a year from its launch, the European Space Agency, and NASA’s Solar Orbiter caught sight of this coronal mass ejection or CME. This view is from the mission’s SoloHI instrument — short for Solar Orbiter Heliospheric Imager — which watches the solar wind, dust, and cosmic rays that fill the space between the Sun and the planets.

It's a brief, grainy view: Solar Orbiter’s remote sensing won’t enter full science mode until November. SoloHI used one of its four detectors at less than 15% of its normal cadence to reduce the amount of data acquired. Still, a keen eye can spot the sudden blast of particles, the CME, escaping the Sun, which is off-camera to the upper right. The CME starts about halfway through the video as a bright burst – the dense leading edge of the CME – and drifts off-screen to the left.

For SoloHI, catching this CME was a happy accident. At the time the eruption reached the spacecraft, Solar Orbiter had just passed behind the Sun from Earth’s perspective and was coming back around the other side. When the mission was being planned, the team wasn’t expecting to be able to record any data during that time.

A New Space Instrument Captures Its First Solar Eruption, Miles Hatfield, NASA

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Volume of Chaos...

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Topics: Astronomy, Astrophysics, Cosmology

Physicists have spent centuries grappling with an inconvenient truth about nature: Faced with three stars on a collision course, astronomers could measure their locations and velocities in nanometers and milliseconds and it wouldn’t be enough to predict the stars’ fates. 

But the cosmos frequently brings together trios of stars and black holes. If astrophysicists hope to fully understand regions where heavenly bodies mingle in throngs, they must confront the “three-body problem.” 

While the result of a single three-body event is unknowable, researchers are discovering how to predict the range of outcomes of large groups of three-body interactions. In recent years, various groups have figured out how to make statistical forecasts of hypothetical three-body matchups: For instance, if Earth tangled with Mars and Mercury thousands of times, how often would Mars get ejected? Now, a fresh perspective developed by physicist Barak Kol simplifies the probabilistic “three-body problem,” by looking at it from an abstract new perspective. The result achieves some of the most accurate predictions yet. 

Physicists Edge Closer to Taming the Three-Body Problem, Charlie Wood, Scientific American

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Antistars...

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Astronomers searched for candidate antimatter stars among nearly 6000 gamma-ray sources. After eliminating known objects and sources that lacked the spectral signature of an antistar, 14 possibles remained. (Courtesy: Simon Dupourqué/IRAP)

Topics: Astronomy, Astrophysics, Cosmology, High Energy Physics

Fourteen possible antimatter stars (“antistars”) have been flagged up by astronomers searching for the origin of puzzling amounts of antihelium nuclei detected coming from deep space by the Alpha Magnetic Spectrometer (AMS-02) on the International Space Station.

Three astronomers at the University of Toulouse – Simon Dupourqué, Luigi Tibaldo, and Peter von Ballmoos – found the possible antistars in archive gamma-ray data from NASA’s Fermi Gamma-ray Space Telescope. While antistars are highly speculative, if they are real, then they may be revealed by their production of weak gamma-ray emission peaking at 70 MeV, when particles of normal matter from the interstellar medium fall onto them and are annihilated.

Antihelium-4 was created for the first time in 2011, in particle collisions at the Relativistic Heavy Ion Collider at the Brookhaven National Laboratory. At the time, scientists stated that if antihelium-4 were detected coming from space, then it would definitely have to come from the fusion process inside an antistar.

However, when it was announced in 2018 that AMS-02 had tentatively detected eight antihelium nuclei in cosmic rays – six of antihelium-3 and two of antihelium-4 – those unconfirmed detections were initially attributed to cosmic rays colliding with molecules in the interstellar medium and producing the antimatter in the process.

Subsequent analysis by scientists including Vivian Poulin, now at the University of Montpellier, cast doubt on the cosmic-ray origin since the greater the number of nucleons (protons and neutrons) that an antimatter nucleus has, the more difficult it is to form from cosmic ray collisions. Poulin’s group calculated that antihelium-3 is created by cosmic rays at a rate 50 times less than that detected by the AMS, while antihelium-4 is formed at a rate 105 times less.

The mystery of matter and antimatter

The focus has therefore turned back to what at first may seem an improbable explanation – stars made purely from antimatter. According to theory, matter and antimatter should have been created in equal amounts in the Big Bang, and subsequently, all annihilated leaving a universe full of radiation and no matter. Yet since we live in a matter-dominated universe, more matter than antimatter must have been created in the Big Bang – a mystery that physicists have grappled with for decades.

“Most scientists have been persuaded for decades now that the universe is essentially free of antimatter apart from small traces produced in collisions of normal matter,” says Tibaldo.

The possible existence of antistars threatens to turn this on its head. “The definitive discovery of antihelium would be absolutely fundamental,” says Dupourqué.

Are antimatter stars firing bullets of antihelium at Earth? Physics World, published in Physical Review D

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Meh...

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Topics: Astrobiology, Astronomy, Cosmology, SETI

I would extend his theme to cover something that comes naturally to us all, which I’ll call Pseudo-exceptionalism—the unearned conviction that we are exceptional, superior to others because we were born...us.

We simply assume that we’re kinder, more honest, more realistic, more wholesome than those around us. After all, we’re married to ourselves for life, so we make accommodations: We cut ourselves slack. We’re fast to forgive ourselves. When challenged, we’re much better at making our case than our opponent’s. We spot injustices to ourselves far faster than we spot our injustices to others.</em>

Why Some People (Maybe Even Us) Think They're So Special
… and what to do about it. Jeremy E. Sherman Ph.D., MPP, Psychology Today

It is presumptuous to assume that we are worthy of special attention from advanced species in the Milky Way. We may be a phenomenon as uninteresting to them as ants are to us; after all, when we’re walking down the sidewalk we rarely if ever examine every ant along our path.

Our sun formed at the tail end of the star formation history of the universe. Most stars are billions of years older than ours. So much older, in fact, that many sunlike stars have already consumed their nuclear fuel and cooled off to a compact Earth-size remnant known as a white dwarf. We also learned recently that of order half of all sunlike stars host an Earth-size planet in their habitable zone, allowing for liquid water and for the chemistry of life.

Since the dice of life were rolled in billions of other locations within the Milky Way under similar conditions to those on Earth, life as we know it is likely common. If that is indeed the case, some intelligent species may well be billions of years ahead of us in their technological development. When weighing the risks involved in interactions with less-developed cultures such as ours, these advanced civilizations may choose to refrain from contact. The silence implied by Fermi's paradox (“Where is everybody?”) may mean that we are not the most attention-worthy cookies in the jar.

Why Do We Assume Extraterrestrials Might Want to Visit Us? Avi Loeb, Scientific American

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The Question is Moot...

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Topics: Astrobiology, Astronomy, Astrophysics, SETI

 

Cultural references: The post title refers to NC A&T Alumni, and Civil Rights icon Reverend Jesse Jackson's appearance on Saturday Night Live, and the Wow! signal. Personal note: This signal appeared on the same day my granddaughter was born.

 

<p>On April 29, 2019, the Parkes Radio Telescope in Australia began listing to the radio signals from the Sun’s nearest neighbor, Proxima Centauri, just over 4 lightyears away. The telescope was looking for evidence of solar flares and so listened for 30 minutes before retraining on a distant quasar to recalibrate and then pointing back.

 

In total, the telescope gathered 26 hours of data. But when astronomers analyzed it in more detail, they noticed something odd — a single pure tone at a frequency of 982.02 MHz that appeared five times in the data.

 

The signal was first reported last year in The Guardian, a British newspaper. The article raised the possibility that the signal may be evidence of an advanced civilization on Proxima Centauri, a red dwarf star that is known to have an Earth-sized planet orbiting in its habitable zone.

 

But researchers have consistently played down this possibility saying that, at the very least, the signal must be observed again before any conclusions can be drawn. Indeed, the signal has not been seen again, despite various searches.

 

Now Amir Siraj and Abraham Loeb from Harvard University in Cambridge, Massachusetts, have calculated the likelihood that the signal came from a Proxima Centauri-based civilization, even without another observation. They say the odds are so low as to effectively rule out the possibility — provided the assumptions they make in their calculations are valid.</p>

 

Why The Recent Signal That Appeared to Come From Proxima Centauri Almost Certainly Didn't, Physics arXiv Blog, Discovery Magazine

 

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Nabta Playa...

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The stone circle of Nabta Playa marks the summer solstice, a time that coincided with the arrival of monsoon rains in the Sahara Desert thousands of years ago. (Credit: Wikimedia Commons)

Topics: African Studies, Astronomy, Astrophysics, Diversity in Science

For thousands of years, ancient societies all around the world erected massive stone circles, aligning them with the sun and stars to mark the seasons. These early calendars foretold the coming of spring, summer, fall, and winter, helping civilizations track when to plant and harvest crops. They also served as ceremonial sites, both for celebration and sacrifice.

These megaliths — large, prehistoric monuments made of stone — may seem mysterious in our modern era, when many people lack a connection with, or even view of, the stars. Some even hold them up as supernatural or divined by aliens. But many ancient societies kept time by tracking which constellations rose at sunset, like reading a giant, celestial clock. And others pinpointed the sun’s location in the sky on the summer and winter solstice, the longest and shortest days of the year, or the spring and fall equinox.

Europe alone holds some 35,000 megaliths, including many astronomically-aligned stone circles, as well as tombs (or cromlechs) and other standing stones. These structures were mostly built between 6,500 and 4,500 years ago, largely along the Atlantic and Mediterranean coasts.

The most famous of these sites is Stonehenge, a monument in England that’s thought to be around 5,000 years old. Though still old, at that age, Stonehenge may have been one of the youngest such stone structures to be built in Europe.

The chronology and extreme similarities between these widespread European sites lead some researchers to think the regional tradition of constructing megaliths first emerged along the coast of France. It was then passed across the region, eventually reaching Great Britain.

But even these primitive sites are at least centuries younger than the world’s oldest known stone circle: Nabta Playa.

Located in Africa, Nabta Playa stands some 700 miles south of the Great Pyramid of Giza in Egypt. It was built more than 7,000 years ago, making Nabta Playa the oldest stone circle in the world — and possibly Earth’s oldest astronomical observatory. It was constructed by a cattle worshiping cult of nomadic people to mark the summer solstice and the arrival of the monsoons.

“Here is human beings’ first attempt to make some serious connection with the heavens," says J. McKim Malville, a professor emeritus at the University of Colorado and archeoastronomy expert.

Nabta Playa: The World's First Astronomical Site Was Built in Africa and Is Older Than Stonehenge, Eric Betz, Discover Magazine

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TNOs...

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Topics: Astronomy, Astrophysics, Comets, Space Exploration

 

Invisible structures generated by gravitational interactions in the Solar System have created a "space superhighway" network, astronomers have discovered.

 

These channels enable the fast travel of objects through space and could be harnessed for our own space exploration purposes, as well as the study of comets and asteroids.

 

By applying analyses to both observational and simulation data, a team of researchers led by Nataša Todorović of Belgrade Astronomical Observatory in Serbia observed that these superhighways consist of a series of connected arches inside these invisible structures, called space manifolds - and each planet generates its own manifolds, together creating what the researchers have called "a true celestial autobahn."

 

This network can transport objects from Jupiter to Neptune in a matter of decades, rather than the much longer timescales, on the order of hundreds of thousands to millions of years, normally found in the Solar System.

 

Finding hidden structures in space isn't always easy, but looking at the way things move around can provide helpful clues. In particular, comets and asteroids.

 

There are several groups of rocky bodies at different distances from the Sun. There's the Jupiter-family comets (JFCs), those with orbits of less than 20 years, that don't go farther than Jupiter's orbital paths.

 

Centaurs are icy chunks of rocks that hang out between Jupiter and Neptune. And the trans-Neptunian objects (TNOs) are those in the far reaches of the Solar System, with orbits larger than that of Neptune.

 

Astronomers Just Found Cosmic 'Superhighways' For Fast Travel Through The Solar System, Michelle Starr (no kidding), Science Alert

 

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Twins of a Young Sun...

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The first direct image of two exoplanets orbiting a Sun-like star, seen here, was captured by the SPHERE instrument on the ESO’s Very Large Telescope. The system is called TYC 8998-760-1 and is located some 300 light-years from Earth.

 

Topics: Astronomy, Astrophysics, Exoplanets

In another exoplanetary first, the European Southern Observatory's Very Large Telescope (VLT) in Chile's Atacama Desert has captured an image of two worlds orbiting a younger version of the Sun. The system, called TYC 8998-760-1, is located roughly 300 light-years away in the southern constellation Musca. And although it hides two gas giants orbiting a Sun-like star, we don’t have anything quite like these worlds in our own solar system.

The inner planet lies about 160 astronomical units from its host star (where one astronomical unit, or AU, is the average Earth-Sun distance) and is some 14 times the mass of Jupiter. With that amount of heft, the gas giant skirts the border between planet and brown dwarf, which is a type of almost-star. The more distant planet is located about 320 AU from its star and weighs in at about six Jupiter masses.

Two exoplanets seen dancing around Sun-like star for the first time, Mark Zastrow, Astronomy.com

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Starspots and Red Giants...

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Red-giant spotter: artist’s impression of the Kepler space telescope in Earth orbit. (Courtesy: NASA)

 

Topics: Astronomy, Astrophysics, Solar Physics

Some red-giant stars are rotating much faster than previously thought, according to a study led by Patrick Gaulme at Germany’s Max Planck Institute for Solar System Research. Using NASA’s Kepler space telescope, the astronomers found that about 8% of the red giants they observed are rotating fast enough to display starspots. The team reckons that the elderly stars acquire their rapid rotation by following one of three distinct routes in their evolution.

In main sequence stars like the Sun, the complex interplay that occurs between stellar rotation and the motions of plasma creates incredibly lively magnetic fields. When this magnetic activity is particularly strong, upwelling plumes of plasma in a star’s convective outer layers can be blocked, producing dark patches on its surface. To an observer on Earth, these starspots cause a periodic variation in the star’s brightness as it rotates, bringing the spots in and out of our field of view.

Until recently, starspots were not thought to be present on red giant surfaces. Since these older stars expand rapidly as they move out of the main sequence, while maintaining their angular momentum, previous theories had predicted that they must rotate more slowly than main sequence stars. Slower rotation should reduce magnetic activity, preventing starspots from forming.

Starspot study sheds light on why some red giants spin faster than others, Sam Jarman, Physics World

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Comet NEOWISE...

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Comet NEOWISE over Mount Hood on July 11, 2020. Credit: Kevin Morefield Getty Images

 

Topics: Astronomy, Astrophysics, Comets

Comet NEOWISE has been entertaining space enthusiasts across the Northern Hemisphere. Although its official name is C/2020 F3, the comet has been dubbed NEOWISE after the Near-Earth Object Wide-Field Infrared Survey Explorer (NEOWISE) space telescope that first noticed it earlier this year. This “icy snowball” with a gassy tail made its closest approach to the sun on July 3 and is now heading back from whence it came: the far reaches of the outer solar system. Its long, looping orbit around our star ensures that after passing closest to Earth on July 22, Comet NEOWISE will not return for some 6,800 years.

Even though the comet is now bright enough to observe with unaided eyes, inexperienced stargazers might have trouble knowing when and where to look. Scientific American spoke to Jackie Faherty, an astronomer at the American Museum of Natural History in New York City, for observing tips and a better appreciation of why comets are so special.

How does one prepare to watch Comet NEOWISE with the naked eye?

Find the darkest possible swath of sky and make sure your eyes are adjusted so that you give yourself the best possible opportunity to see faint objects. It means: don’t just walk outside after staring at lights or screens and expect to see [the comet] really well. You need 15 minutes or so to adjust your eyes, so that your pupils are adjusted, and they’re used to seeing fainter things. It’s the same as walking into a dark room, and everybody knows that [you] can’t see [things] first—and then, all of a sudden, you start seeing things. You need to do the same thing when you walk outside. And use the Comet NEOWISE app developed by astrophysicist Hanno Rein of University of Toronto Scarborough to see exactly where it is, so that you know what direction you need to look. And then the key would be to find yourself a place that is the darkest possible, that [has] no lights.

The Best Way to Watch Comet NEOWISE, Wherever You Are, Karen Kwon, Scientific American

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Our Galaxy's Water Worlds...

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This artist’s concept shows a hypothetical planet covered in water around the binary star system of Kepler-35A and B. The composition of such water worlds has fascinated astronomers and astrophysicists for years. (Image by NASA/JPL-Caltech.)

 

Topics: Astronomy, Astrobiology, Astrophysics, Cosmology, Exoplanets

Out beyond our solar system, visible only as the smallest dot in space with even the most powerful telescopes, other worlds exist. Many of these worlds, astronomers have discovered, may be much larger than Earth and completely covered in water — basically ocean planets with no protruding land masses. What kind of life could develop on such a world? Could a habitat like this even support life?

A team of researchers led by Arizona State University (ASU) recently set out to investigate those questions. And since they couldn’t travel to distant exoplanets to take samples, they decided to recreate the conditions of those water worlds in the laboratory. In this case, that laboratory was the Advanced Photon Source (APS), a U.S. Department of Energy (DOE) Office of Science User Facility at the DOE’s Argonne National Laboratory.

What they found — recently published in Proceedings of the National Academy of Sciences — was a new transitional phase between silica and water, indicating that the boundary between water and rock on these exoplanets is not as solid as it is here on Earth. This pivotal discovery could change the way astronomers and astrophysicists have been modeling these exoplanets, and inform the way we think about life evolving on them.

Dan Shim, associate professor at ASU, led this new research. Shim leads ASU’s Lab for Earth and Planetary Materials and has long been fascinated by the geological and ecological makeup of these distant worlds. That composition, he said, is nothing like any planet in our solar system — these planets may have more than 50% water or ice atop their rock layers, and those rock layers would have to exist at very high temperatures and under crushing pressure.

Beneath the surface of our galaxy’s water worlds, Andre Salles, Argonne National Laboratory

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40 Eridani A...

 

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Vulcan from the link, also see Memory Alpha

 

Topics: Astronomy, Astrophysics, Exoplanets, Science Fiction, Star Trek

Note: 2018 article, but neat nonetheless.

One of the more interesting and rewarding aspects of astronomy and space exploration is seeing science fiction become science fact. While we are still many years away from colonizing the Solar System or reaching the nearest stars (if we ever do), there are still many rewarding discoveries being made that are fulfilling the fevered dreams of science fiction fans.

For instance, using the Dharma Planet Survey, an international team of scientists recently discovered a super-Earth orbiting a star just 16 light-years away. This super-Earth is not only the closest planet of its kind to the Solar System, it also happens to be located in the same star system as the fictional planet Vulcan from the Star Trek universe.

The study which details their findings, which recently appeared in the Monthly Notices of the Royal Astronomical Society, was led by Bo Ma and Jian Ge, a post-doctoral researcher and a professor of astronomy from the University of Florida, respectively. They were joined by researchers from Tennessee State University, the Instituto de Astrofisica de Canarias, the Universidad de La Laguna, Vanderbilt University, the University of Washington, and the University of Arizona’s Steward Observatory.

“The new planet is a ‘super-Earth’ orbiting the star HD 26965, which is only 16 light years from Earth, making it the closest super-Earth orbiting another Sun-like star. The planet is roughly twice the size of Earth and orbits its star with a 42-day period just inside the star’s optimal habitable zone.”

“Star Trek fans may know the star HD 26965 by its alternative moniker, 40 Eridani A,” he said. “Vulcan was connected to 40 Eridani A in the publications “Star Trek 2” by James Blish (Bantam, 1968) and “Star Trek Maps” by Jeff Maynard (Bantam, 1980).”

Astronomers find Planet Vulcan – 40 Eridani A – Right Where Star Trek Predicted it, Universe Today

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Improving View...

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View of the Alpha Centauri system. The bright binary star Alpha Centauri AB lies at the upper left. The much fainter red dwarf star Proxima Centauri is barely discernible towards the lower right of the picture. Credit: Digitized Sky Survey 2; Acknowledgement: Davide De Martin and Mahdi Zamani

 

Topics: Astronomy, Astrophysics, Exoplanets, Space Exploration


Little is more enticing than the prospect of seeing alien worlds around other stars—and perhaps one day even closely studying their atmosphere and mapping their surface. Such observations are exceedingly difficult, of course. Although more than 4,000 exoplanets are now known, the vast majority of them are too distant and dim for our best telescopes to discern against the glare of their host star. Exoplanets near our solar system provide easier imaging opportunities, however. And no worlds are nearer to us than those thought to orbit the cool, faint red dwarf Proxima Centauri—the closest star to our sun at 4.2 light-years away.

In 2016 astronomers discovered the first known planet in this system: the roughly Earth-sized Proxima b. But because of its star-hugging 11-day orbit around Proxima Centauri, Proxima b is a poor candidate for imaging. Proxima c, by contrast, offers much better chances. Announced in 2019, based on somewhat circumstantial evidence, the planet remains unconfirmed. If real, it is estimated to be several times more massive than Earth—a so-called super Earth or mini Neptune—and to orbit Proxima Centauri at about 1.5 times the span between Earth and the sun. Its size and distance from its star make the world a tempting target for current and near-future exoplanet-imaging projects. Now, in a new preprint paper accepted for publication in the journal Astronomy & Astrophysics, some astronomers say they might—just might— have managed to see Proxima c for the first time.

“This planet is extremely interesting because Proxima is a star very close to the sun,” says Raffaele Gratton of the Astronomical Observatory of Padova in Italy, who is the study’s lead author. “The idea was that since this planet is [far] from the star, it is possible that it can be observed in direct imaging. We found a reasonable candidate that looks like we have really detected the planet.”

 

Astronomers May Have Captured the First Ever Image of Nearby Exoplanet Proxima C
Jonathan O'Callaghan, Scientific American

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Pioneer...

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Burbidge, pictured with her husband and research partner, Geoffrey, was appointed to numerous leadership positions previously held only by men. | W.W. Girdner/Caltech Archives

 

Topics: Astronomy, Astrophysics, Diversity, Diversity in Science, Women in Science


Margaret Burbidge, a past president of the American Association for the Advancement of Science who overcame gender discrimination on the way to becoming one of the most influential astrophysicists of her time, died on April 5 at her home in San Francisco. She was 100.

In 1957, Burbidge was the lead author of a study detailing the chemical processes by which elements heavier than lithium, including the carbon and oxygen that drive life on Earth, are created inside stars. The origins of such elements were previously unknown, and the research paper is the foundation of current understanding of what astronomers now call stellar nucleosynthesis.

Later in her career, Burbidge was appointed to numerous leadership positions previously held only by men and helped develop the Faint Object Spectrograph, one of the original scientific instruments aboard NASA’s Hubble Space Telescope. The FOS team provided the first strong, observational evidence for the existence of a supermassive black hole in the core of another galaxy.

Eleanor Margaret Peachey was born in Davenport, England, on August 12, 1919. Her father was a chemistry lecturer in nearby Manchester, and her mother had been one of his students.

When Peachey was two, the family moved to London, where cloudy skies often prevented starlight from reaching the city.

“The first time I consciously remember really noticing the stars was the summer that I was four, and we were going on a night crossing to France for summer vacation,” Burbidge said in a 1978 interview with the American Institute of Physics. “These twinkling lights became another fascination to me.”

Aware of her interest in the stars, Peachey’s grandfather gave her books by English astronomer James Jeans for her 12th and 13th birthdays. By the age of 19, she had graduated with honors from University College London, where she studied astronomy, physics and mathematics. In 1943, she earned her Ph.D. from UCL.

After receiving her doctorate in the midst of World War II, Peachey continued to use the telescope at the UCL Observatory, sometimes with bombs exploding in the city around her. Hoping to work with better equipment and clearer skies, she applied for a fellowship that would have placed her at the Mount Wilson Observatory outside of Los Angeles.

“The turn-down letter simply pointed out that Carnegie Fellowships were available only for men,” Burbidge wrote in a 1994 memoir. “A guiding operational principle in my life was activated: If frustrated in one’s endeavor by a stone wall or any kind of blockage, one must find a way around — another route towards one’s goal. This is advice I have given to many women facing similar situations.”

In 1948, Peachey married Geoffrey Burbidge, a UCL graduate student in physics who soon switched fields to collaborate with his wife on her astronomy research. When Geoff applied for the same Carnegie Fellowship, he was accepted, and Margaret took a position at the California Institute of Technology in Pasadena. When they needed to use the Mount Wilson telescope, the couple would arrive with Margaret posing as her husband’s assistant.

 

In Memoriam:
Margaret Burbidge, Pioneering Astronomer and Advocate for Women in Science
Adam D. Cohen, American Association for the Advancement of Science

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TNOs and Planet Nine...

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Over the past decade or so, astronomers have discovered a number of far-flung objects that all have very similar perihelia, meaning they make their closest approaches to the Sun at about the same location in space. One leading theory that attempts to explain the clustering is that a massive and unseen world known as Planet Nine hiding in the outer solar system.

Fauxtoez/WikiMedia Commons

 

Topics: Astronomy, Astrophysics, Exoplanets, Space Exploration


Note: Not an April 1st joke. With the COVID-19 crisis, I literally had to peruse some sites that DIDN'T talk about what we're all living through. It's been rough, thinking about how and when this all ends. I'll try to get my sea legs back to blogging about science. Bear with me. I'm human.

Astronomers have discovered 139 new minor planets orbiting the Sun beyond Neptune by searching through data from the Dark Energy Survey. The new method for spotting small worlds is expected to reveal many thousands of distant objects in coming years — meaning these first hundred or so are likely just the tip of the iceberg.

Taken together, the newfound distant objects, as well as those to come, could resolve one of the most fascinating questions of modern astronomy: Is there a massive and mysterious world called Planet Nine lurking in the outskirts of our solar system?

Neptune orbits the Sun at a distance of about 30 astronomical units (AU; where 1 AU is the Earth-Sun distance). Beyond Neptune lies the Kuiper Belt — a comet-rich band of frozen, rocky objects (including Pluto) that holds dozens to hundreds of times more mass than the asteroid belt. Both within the Kuiper Belt and past its outer edge at 50 AU orbit distant bodies called trans-Neptunian objects (TNOs). Currently, we know of nearly 3,000 TNOs in the solar system, but estimates put the total number closer to 100,000.

As more and more TNOs have been discovered over the years, some astronomers — including Konstantin Batygin and Mike Brown of Caltech — have noticed a small subset of these objects have peculiar orbits. They seem to bunch up in unexpected ways, as if an unseen object is herding these so-called extreme TNOs (eTNOs) into specific orbits. Batygin and Brown — in addition to other groups, like that led by Scott Sheppard of the Carnegie Institution for Science — think these bizarrely orbiting eTNOs point to the existence of a massive, distant world called Planet Nine.

Hypothesized to be five to 15 times the mass of Earth and to orbit some 400 AU (or farther) from the Sun, the proposed Planet Nine would have enough of a gravitational pull that it could orchestrate the orbits of the eTNOs, causing them to cluster together as they make their closest approaches to the Sun.

The problem is that the evidence for Planet Nine is so far indirect and sparse. There could be something else that explains the clumped orbits, or perhaps researchers stumbled on a few objects that just happen to have similar orbits. Discovering more TNOs, particularly beyond the Kuiper Belt, will allow astronomers to find more clues that could point to the location of the proposed Planet Nine — or deny its existence altogether. Of the 139 newly discovered minor planets found in this study, seven are eTNOs, which is a significant addition to a list that numbered around a dozen just a few months ago.

 

Astronomers find 139 new minor planets in the outer solar system
Erica Naone, Astronomy

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Primordial Black Holes...

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Snapshot from the central region of a numerical simulation of two merging neutron stars. It shows the stars stretched out by tidal forces just before their collision. Credit: CoRe/Jena FSU

 

Topics: Astronomy, Astrophysics, Black Holes, Einstein, General Relativity


In the nearly five years since their first direct detection, gravitational waves have become one of the hottest topics in astronomy. With facilities such as the Laser Interferometer Gravitational-Wave Observatory (LIGO), researchers have mostly used these ripples in spacetime to study the inner workings of merging black holes, but LIGO has also detected gravitational waves from other sorts of celestial crashes, such as the collisions of ultradense stellar remnants called neutron stars. Sometimes, however, LIGO serves up gravitational waves that leave astronomers scratching their heads—as was the case for GW190425, an event detected last April that was recently attributed to a neutron star merger.

The trouble is that LIGO’s data suggest this neutron star pair was substantially overweight—collectively, some 3.4 times the mass of the sun, which is half a solar mass heavier than the most massive neutron star binaries ever seen. “It is the heaviest known by a pretty wide margin,” says Chad Hanna, an astrophysicist at Pennsylvania State University who hunts gravitational waves.

The trouble is that LIGO’s data suggest this neutron star pair was substantially overweight—collectively, some 3.4 times the mass of the sun, which is half a solar mass heavier than the most massive neutron star binaries ever seen. “It is the heaviest known by a pretty wide margin,” says Chad Hanna, an astrophysicist at Pennsylvania State University who hunts gravitational waves.

 

Did Astronomers Just Discover Black Holes from the Big Bang? Nola Taylor Redd, Scientific American

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Through the Looking-Glass...

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An animation shows the random appearance of fast radio bursts (FRBs) across the sky.
(Image: © NRAO Outreach/T. Jarrett (IPAC/Caltech); B. Saxton, NRAO/AUI/NSF)

 

Topics: Astronomy, Astrophysics, Radio Astronomy, Research, Space Exploration


“Curiouser and curiouser!” Cried Alice (she was so much surprised, that for the moment she quite forgot how to speak good English).”

― Lewis Carroll, Alice's Adventures in Wonderland & Through the Looking-Glass


HONOLULU — Mysterious ultra-fast pinpricks of radio energy keep lighting up the night sky and nobody knows why. A newly discovered example of this transient phenomenon has been traced to its place of origin — a nearby spiral galaxy — but it's only made things murkier for astronomers.

The problem concerns a class of blink-and-you'll-miss-them heavenly events known as fast radio bursts (FRBs). In a few thousandths of a second, these explosions produce as much energy as the sun does in nearly a century. Researchers have only known about FRBs since 2007, and they still don't have a compelling explanation regarding their sources.

"The big question is what can produce an FRB," Kenzie Nimmo, a doctoral student at the University of Amsterdam in the Netherlands, said during a news briefing on Monday (Jan. 6) here at the 235th meeting of the American Astronomical Society in Honolulu, Hawaii.
 

FRB 180916.J0158+65, as the object is known, is a repeating FRB discovered by the Canadian Hydrogen Intensity Mapping Experiment (CHIME) observatory, a radio telescope near Okanagan Falls in British Columbia that Nimmo called "the world's best FRB-finding machine."

Follow-up observations by a network of telescopes in Europe allowed the research team to produce a high-resolution image of the FRB's location. This location turned out to be a medium-sized spiral galaxy like our Milky Way that is surprisingly nearby, only 500 million light-years away, making it the closest-known FRB to date. The results were published yesterday (Jan. 6) in the journal Nature.

Origin of Deep-Space Radio Flash Discovered, and It's Unlike Anything Astronomers Have Ever Seen
Adam Mann, Live Science

#P4TC links:

FRBs...December 7, 2015
Fast Radio Bursts and Missing Matter...February 25, 2016
ET, FRBs and Light Sails...March 13, 2017

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