Latest Posts by primordialbitch - Page 2

Pick Your Favorite Findings From Fermi’s First Decade

The Fermi Gamma-ray Space Telescope has been observing some of the most extreme objects and events in the universe — from supermassive black holes to merging neutron stars and thunderstorms — for 10 years. Fermi studies the cosmos using gamma rays, the highest-energy form of light, and has discovered thousands of new phenomena for scientists.

Here are a few of our favorite Fermi discoveries, pick your favorite in the first round of our “Fermi Science Playoff.” 

Colliding Neutron Stars

In 2017, Fermi detected a gamma ray burst at nearly the same moment ground observatories detected gravitational waves from two merging neutron stars. This was the first time light and ripples in space-time were detected from the same source.

The Sun and Moon in Gamma Rays

In 2016, Fermi showed the Moon is brighter in gamma rays than the Sun. Because the Moon doesn’t have a magnetic field, the surface is constantly pelted from all directions by cosmic rays. These produce gamma rays when they run into other particles, causing a full-Moon gamma-ray glow.

Record Rare from a Blazar

The supermassive black hole at the center of the galaxy 3C 279 weighs a billion times the mass of our Sun. In June 2015, this blazar became the brightest gamma-ray source in the sky due to a record-setting flare.

The First Gamma-Ray Pulsar in Another Galaxy

In 2015, for the first time, Fermi discovered a gamma-ray pulsar, a kind of rapidly spinning superdense star, in a galaxy outside our own. The object, located on the outskirts of the Tarantula Nebula, also set the record for the most luminous gamma-ray pulsar we’ve seen so far.

A Gamma-Ray Cycle in Another Galaxy

Many galaxies, including our own, have black holes at their centers. In active galaxies, dust and gas fall into and “feed” the black hole, releasing light and heat. In 2015 for the first time, scientists using Fermi data found hints that a galaxy called PG 1553+113 has a years-long gamma-ray emission cycle. They’re not sure what causes this cycle, but one exciting possibility is that the galaxy has a second supermassive black hole that causes periodic changes in what the first is eating.

Gamma Rays from Novae

A nova is a fairly common, short-lived kind of explosion on the surface of a white dwarf, a type of compact star not much larger than Earth. In 2014, Fermi observed several novae and found that they almost always produce gamma-rays, giving scientists a new type of source to explore further with the telescope.

A Record-Setting Cosmic Blast

Gamma-ray bursts are the most luminous explosions in the universe. In 2013, Fermi spotted the brightest burst it’s seen so far in the constellation Leo. In the first three seconds alone, the burst, called GRB 130427A, was brighter than any other burst seen before it. This record has yet to be shattered.

Cosmic Rays from Supernova Leftovers

Cosmic rays are particles that travel across the cosmos at nearly the speed of light. They are hard to track back to their source because they veer off course every time they encounter a magnetic field. In 2013, Fermi showed that these particles reach their incredible speed in the shockwaves of supernova remains — a theory proposed in 1949 by the satellite’s namesake, the Italian-American physicist Enrico Fermi.

Discovery of a Transformer Pulsar

In 2013, the pulsar in a binary star system called AY Sextanis switched from radio emissions to high-energy gamma rays. Scientists think the change reflects erratic interaction between the two stars in the binary.

Gamma-Ray Measurement of a Gravitational Lens

A gravitational lens is a kind of natural cosmic telescope that occurs when a massive object in space bends and amplifies light from another, more distant object. In 2012, Fermi used gamma rays to observe a spiral galaxy 4.03 billion light-years away bending light coming from a source 4.35 billion light-years away.

New Limits on Dark Matter

We can directly observe only 20 percent of the matter in the universe. The rest is invisible to telescopes and is called dark matter — and we’re not quite sure what it is. In 2012, Fermi helped place new limits on the properties of dark matter, essentially narrowing the field of possible particles that can describe what dark matter is.

‘Superflares’ in the Crab Nebula

The Crab Nebula supernova remnant is one of the most-studied targets in the sky — we’ve been looking at it for almost a thousand years! In 2011, Fermi saw it erupt in a flare five times more powerful than any previously seen from the object. Scientists calculate the electrons in this eruption are 100 times more energetic than what we can achieve with particle accelerators on Earth.

Thunderstorms Hurling Antimatter into Space

Terrestrial gamma-ray flashes are created by thunderstorms. In 2011, Fermi scientists announced the satellite had detected beams of antimatter above thunderstorms, which they think are a byproduct of gamma-ray flashes.

Giant Gamma-Ray Bubbles in the Milky Way

Using data from Fermi in 2010, scientists discovered a pair of “bubbles” emerging from above and below the Milky Way. These enormous bubbles are half the length of the Milky Way and were probably created by our galaxy’s supermassive black hole only a few million years ago.

Hint of Starquakes in a Magnetar

Neutron stars have magnetic fields trillions of times stronger than Earth’s. Magnetars are neutron stars with magnetic fields 1,000 times stronger still. In 2009, Fermi saw a storm of gamma-ray bursts from a magnetar called SGR J1550-5418, which scientists think were related to seismic waves rippling across its surface.

A Dark Pulsar

We observe many pulsars using radio waves, visible light or X-rays. In 2008, Fermi found the first gamma-ray only pulsar in a supernova remnant called CTA 1. We think that the “beam” of gamma rays we see from CTA 1 is much wider than the beam of other types of light from that pulsar. Those other beams never sweep across our vision — only the gamma-rays.

Have a favorite Fermi discovery or want to learn more? Cast your vote in the first of four rounds of the Fermi Science Playoff to help rank Fermi’s findings. Or follow along as we celebrate the mission all year.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

What's a neutron star? I read about them in Bill Bryson's book, but I couldn't figure out why a neutron start would happen in the first place?

When massive stars collapse, the core of the star gets compressed extremely tightly by the force of its own gravity. As the core collapses, the electrons and protons in the core get closer and closer together. Eventually, the core gets so dense that the electrons and protons are forced together, combining into neutrons. The entire core becomes essentially a solid ball of neutrons, as dense as an atomic nuclei. The outer layers of the star, which are also rushing in towards the core, bounce off of this rock-hard layer of neutrons and whiz off into space, creating a supernova and leaving behind a neutron star at the center. And all of this happens in less than a second. Pretty wild. To summarize: neutron stars are giant balls of neutrons that resulted when a stellar core collapsed and became so dense the protons and electrons combined into neutrons. 

Side note: Robert L. Forward wrote a really interesting novel called Dragon’s Egg, which was about intelligent life on a neutron star! It’s quite an interesting read, and you learn a whole lot about neutron stars since the author has a Ph.D in physics. If you want a copy, you can find it here; you won’t find it at a bookstore because it’s out of print, but you can find a used copy online (I linked to one). Let me know if you have any other questions, I’m happy to answer them!

Gobble Up These Black (Hole) Friday Deals!

Welcome to our 6th annual annual Black Hole Friday! Check out these black hole deals from the past year as you prepare to head out for a shopping spree or hunker down at home to avoid the crowds.

First things first, black holes have one basic rule: They are so incredibly dense that to escape their surface you’d have to travel faster than light. But light speed is the cosmic speed limit … so nothing can escape a black hole’s surface!

Black hole birth announcements

Some black holes form when a very large star dies in a supernova explosion and collapses into a superdense object. This is even more jam-packed than the crowds at your local mall — imagine an object 10 times more massive than the Sun squeezed into a sphere with the diameter of New York City!

Some of these collapsing stars also signal their destruction with a huge burst of gamma rays. Our Fermi Gamma-ray Space Telescope and Neil Gehrels Swift Observatory continuously seek out the signals of these gamma ray bursts — black hole birth announcements that come to us from across the universe.

NICER black holes

There are loads of stellar mass black holes, which are just a few 10s of times the Sun’s mass, in our home galaxy alone — maybe even hundreds of millions of them! Our Neutron Star Interior Composition Explorer, or NICER for short, experiment on the International Space Station has been studying some of those relatively nearby black holes.

Near one black hole called GRS 1915+105, NICER found disk winds — fast streams of gas created by heat or pressure. Scientists are still figuring out some puzzles about these types of wind. Where do they come from, for example? And do they change the way material falls into the black hole? Every new example of these disk winds helps astronomers get closer to answering those questions.

Merging monster black holes

But stellar mass black holes aren’t the only ones out there. At the center of nearly every large galaxy lies a supermassive black hole — one with the mass of millions or billions of Suns smooshed into a region no bigger than our solar system.

There’s still some debate about how these monsters form, but astronomers agree that they certainly can collide and combine when their host galaxies collide and combine. Those black holes will have a lot of gas and dust around them. As that material is pulled into the black hole it will heat up due to friction and other forces, causing it to emit light.  A group of scientists wondered what light it would produce and created this mesmerizing visualization showing that most of the light produced around these two black holes is UV or X-ray light. We can’t see those wavelengths with our own eyes, but many telescopes can. Models like this could help scientists know what to look for to spot a merger.

Black holes power bright gamma ray lights

It also turns out that these supermassive black holes are the source of some of the brightest objects in the gamma ray sky! In a type of galaxy called active galactic nuclei (also called “AGN” for short) the central black hole is surrounded by a disk of gas and dust that’s constantly falling into the black hole.

But not only that, some of those AGN have jets of energetic particles that are shooting out from near the black hole at nearly the speed of light! Scientists are studying these jets to try to understand how black holes — which pull everything in with their huge amounts of gravity — provide the energy needed to propel the particles in these jets. If that jet is pointed directly at us, it can appear super-bright in gamma rays and we call it a blazar. These blazars make up more than half of the sources our Fermi space telescope sees.

Catching particles from near a black hole

Sometimes scientists get a two-for-one kind of deal when they’re looking for black holes. Our colleagues at the IceCube Neutrino Observatory actually caught a particle from a blazar 4 billion light-years away. IceCube lies a mile under the ice in Antarctica and uses the ice itself to detect neutrinos, tiny speedy particles that weigh almost nothing and rarely interact with anything. When IceCube caught a super-high-energy neutrino and traced its origin to a specific area of the sky, they turned to the astronomical community to pinpoint the source.

Our Fermi spacecraft scans the entire sky about every three hours and for months it had observed a blazar producing more gamma rays than usual. Flaring is a common characteristic in blazars, so this didn’t attract special attention. But when the alert from IceCube came through, scientists realized the neutrino and the gamma rays came from the same patch of sky! This method of using two or more kinds of signals to learn about one event or object is called multimessenger astronomy, and it’s helping us learn a lot about the universe.

Get more fun facts and information about black holes HERE and follow us on social media today for other cool facts and findings about black holes!

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Neutron Stars Collide

The recent detection of two neutron stars colliding has sent waves through spacetime and the astronomical community.

You may have seen headlines in the news and not really know why this is such a big deal.

Here’s the Sparknotes version:

A while back a thing called “gravitational waves” were observed for the first time. These are fluctuations in the fabric of spacetime that propagate out from their source just like light, i.e. radially/like a pebble dropped in water. General relativity shows us that the acceleration of objects with mass cause this event to occur.

Until fairly recently these have been too difficult to observe and in fact Einstein didn’t think we’d ever be able to. A series of laser interferometers have disproved that assumption. Using high-precision analysis of how the lasers shift as a gravitational wave moves through them scientists can now see the small movements in the universe that are gravitational waves.

Importantly, we now have three such observatories capable of working together. Known as the “LIGO-Virgo” team, two observatories in the U.S. and one in Italy detected these shifting in spacetime. Three is a pretty magical number in coordinating detections like this because you can then triangulate where the signal comes from and…

BINGO! Within hours optical observatories were zeroing in on the predicted source of these spacetime fluctuations. Indeed, they confirmed the presence of a previously unseen glow:

What you’re looking at is the glow of two neutron stars colliding into each other. This explosion has the energy of approximately 260,000,000 suns.

Each of these stars has such a large mass that the waves in spacetime are actually detectable from a distance of 140 million light-years away.

Impressive, right? Although you might agree, this still begs the question of what exactly we’ve learned from this event. Well - a lot. Since this is the first observation we have made with both gravitational wave observatories and more traditional astronomical observatories (i.e. light detecting ones) we’ve been able to put some numbers on the phenomenon. Here are some of the things we’ve learned:

1) Gravitational waves propagate at the speed of light!

2) A huge portion of heavier elements (like gold and uranium!) may have their origins in neutron star collisions! Nuclear synthesis in stars more typical like the sun is restricted to closer to 10% of the star’s mass being able to fuse elements together into new ones. This process is actually quite inefficient (actually, YOU are a more efficient radiator than the sun!) and it becomes more difficult for a star to fuse the heavier elements. Before this event we didn’t have a good way of explaining why we found so much more heavy stuff than stellar nuclear synthesis could account for. Now? Baboom! This neutron star collision resulted in the synthesis of so much gold that it’s about 150 times more massive than the Earth! Cha-Ching!

So if you’re an amateur (or professional, I suppose) astronomer and you want to see this collision, now dubbed GW170817, and you build a little radio telescope (another post!), you’ll be able to detect this collision for the next 5-10 years due to the afterglow.

(Image credit: NASA and ESA)

Pls tell me interesting facts about stars

Interesting facts about stars:

Heavy stars blow up and make heavier elements like gold. So, every bit of gold you’ve ever seen, worn, or touched came from the dying explosion of a star. Other elements made in supernovae include anything on the periodic table heavier than iron

Heavy stars blow up when they start fusing iron. Meaning, the iron in your frying pan, car, and your blood killed a star at least 3 times the mass of the sun.

Some massive stars that die end up compressing all their mass into a star about 6 miles across, or about the size of a city. This is called a neutron star.

To put this in perspective, these stars start out 3 times as big as our sun and all of their mass is crushed into something the size of a city. The space between atoms is squished away, and the protons and electrons combine to form neutrons. 

Neutron stars are literally as dense as atomic nuclei

Most stars come in pairs

The most common stellar type is a red dwarf, which is a small, red, dim, cool star.

Honestly, that’s just the first few that come to mind, space is really crazy.

Black Hole Image Makes History; NASA Telescopes Coordinated Observations

A black hole and its shadow have been captured in an image for the first time, a historic feat by an international network of radio telescopes called the Event Horizon Telescope (EHT). EHT is an international collaboration whose support in the U.S. includes the National Science Foundation.

A black hole is an extremely dense object from which no light can escape. Anything that comes within a black hole’s “event horizon,” its point of no return, will be consumed, never to re-emerge, because of the black hole’s unimaginably strong gravity. By its very nature, a black hole cannot be seen, but the hot disk of material that encircles it shines bright. Against a bright backdrop, such as this disk, a black hole appears to cast a shadow.   

The stunning new image shows the shadow of the supermassive black hole in the center of Messier 87 (M87), an elliptical galaxy some 55 million light-years from Earth. This black hole is 6.5 billion times the mass of the Sun. Catching its shadow involved eight ground-based radio telescopes around the globe, operating together as if they were one telescope the size of our entire planet. 

“This is an amazing accomplishment by the EHT team,” said Paul Hertz, director of the astrophysics division at NASA Headquarters in Washington. “Years ago, we thought we would have to build a very large space telescope to image a black hole. By getting radio telescopes around the world to work in concert like one instrument, the EHT team achieved this, decades ahead of time.”

To complement the EHT findings, several NASA spacecraft were part of a large effort, coordinated by the EHT’s Multiwavelength Working Group, to observe the black hole using different wavelengths of light. As part of this effort, NASA’s Chandra X-ray Observatory, Nuclear Spectroscopic Telescope Array (NuSTAR) and Neil Gehrels SwiftObservatory space telescope missions, all attuned to different varieties of X-ray light, turned their gaze to the M87 black hole around the same time as the Event Horizon Telescope in April 2017. If EHT observed changes in the structure of the black hole’s environment, data from these missions and other telescopes could be used to help figure out what was going on. 

While NASA observations did not directly trace out the historic image, astronomers used data from NASA’s Chandra and NuSTAR satellites to measure the X-ray brightness of M87’s jet. Scientists used this information to compare their models of the jet and disk around the black hole with the EHT observations. Other insights may come as researchers continue to pore over these data. 

There are many remaining questions about black holes that the coordinated NASA observations may help answer. Mysteries linger about why particles get such a huge energy boost around black holes, forming dramatic jets that surge away from the poles of black holes at nearly the speed of light. When material falls into the black hole, where does the energy go? 

“X-rays help us connect what’s happening to the particles near the event horizon with what we can measure with our telescopes,” said Joey Neilsen, an astronomer at Villanova University in Pennsylvania, who led the Chandra and NuSTAR analysis on behalf of the EHT’s Multiwavelength Working Group.

NASA space telescopes have previously studied a jet extending more than 1,000 light-years away from the center of M87. The jet is made of particles traveling near the speed of light, shooting out at high energies from close to the event horizon. The EHT was designed in part to study the origin of this jet and others like it. A blob of matter in the jet called HST-1, discovered by Hubble astronomers in 1999, has undergone a mysterious cycle of brightening and dimming.

Chandra, NuSTAR and Swift, as well as NASA’s Neutron star Interior Composition Explorer (NICER) experiment on the International Space Station, also looked at the black hole at the center of our own Milky Way galaxy, called Sagittarius A*, in coordination with EHT.   

Getting so many different telescopes on the ground and in space to all look toward the same celestial object is a huge undertaking in and of itself, scientists emphasize. 

“Scheduling all of these coordinated observations was a really hard problem for both the EHT and the Chandra and NuSTAR mission planners,” Neilsen said. “They did really incredible work to get us the data that we have, and we’re exceedingly grateful.”

Neilsen and colleagues who were part of the coordinated observations will be working on dissecting the entire spectrum of light coming from the M87 black hole, all the way from low-energy radio waves to high-energy gamma rays. With so much data from EHT and other telescopes, scientists may have years of discoveries ahead. 

Original article:

http://nasa.gov/mission_pages/chandra/news/black-hole-image-makes-history

Time And Space

Gamma-ray Bursts: Black Hole Birth Announcements

Gamma-ray bursts are the brightest, most violent explosions in the universe, but they can be surprisingly tricky to detect. Our eyes can’t see them because they are tuned to just a limited portion of the types of light that exist, but thanks to technology, we can even see the highest-energy form of light in the cosmos — gamma rays.

So how did we discover gamma-ray bursts? 

Accidentally!

We didn’t actually develop gamma-ray detectors to peer at the universe — we were keeping an eye on our neighbors! During the Cold War, the United States and the former Soviet Union both signed the Nuclear Test Ban Treaty of 1963 that stated neither nation would test nuclear weapons in space. Just one week later, the US launched the first Vela satellite to ensure the treaty wasn’t being violated. What they saw instead were gamma-ray events happening out in the cosmos!

Things Going Bump in the Cosmos

Each of these gamma-ray events, dubbed “gamma-ray bursts” or GRBs, lasted such a short time that information was very difficult to gather. For decades their origins, locations and causes remained a cosmic mystery, but in recent years we’ve been able to figure out a lot about GRBs. They come in two flavors: short-duration (less than two seconds) and long-duration (two seconds or more). Short and long bursts seem to be caused by different cosmic events, but the end result is thought to be the birth of a black hole.

Short GRBs are created by binary neutron star mergers. Neutron stars are the superdense leftover cores of really massive stars that have gone supernova. When two of them crash together (long after they’ve gone supernova) the collision releases a spectacular amount of energy before producing a black hole. Astronomers suspect something similar may occur in a merger between a neutron star and an already-existing black hole.

Long GRBs account for most of the bursts we see and can be created when an extremely massive star goes supernova and launches jets of material at nearly the speed of light (though not every supernova will produce a GRB). They can last just a few seconds or several minutes, though some extremely long GRBs have been known to last for hours!

A Gamma-Ray Burst a Day Sends Waves of Light Our Way!

Our Fermi Gamma-ray Space Telescope detects a GRB nearly every day, but there are actually many more happening — we just can’t see them! In a GRB, the gamma rays are shot out in a narrow beam. We have to be lined up just right in order to detect them, because not all bursts are beamed toward us — when we see one it’s because we’re looking right down the barrel of the gamma-ray gun. Scientists estimate that there are at least 50 times more GRBs happening each day than we detect!

So what’s left after a GRB — just a solitary black hole? Since GRBs usually last only a matter of seconds, it’s very difficult to study them in-depth. Fortunately, each one leaves an afterglow that can last for hours or even years in extreme cases. Afterglows are created when the GRB jets run into material surrounding the star. Because that material slows the jets down, we see lower-energy light, like X-rays and radio waves, that can take a while to fade. Afterglows are so important in helping us understand more about GRBs that our Neil Gehrels Swift Observatory was specifically designed to study them!

Last fall, we had the opportunity to learn even more from a gamma-ray burst than usual! From 130 million light-years away, Fermi witnessed a pair of neutron stars collide, creating a spectacular short GRB. What made this burst extra special was the fact that ground-based gravitational wave detectors LIGO and Virgo caught the same event, linking light and gravitational waves to the same source for the first time ever!

For over 10 years now, Fermi has been exploring the gamma-ray universe. Thanks to Fermi, scientists are learning more about the fundamental physics of the cosmos, from dark matter to the nature of space-time and beyond. Discover more about how we’ll be celebrating Fermi’s achievements all year!

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

Black Holes are NICER Than You Think!

We’re learning more every day about black holes thanks to one of the instruments aboard the International Space Station! Our Neutron star Interior Composition Explorer (NICER) instrument is keeping an eye on some of the most mysterious cosmic phenomena.

We’re going to talk about some of the amazing new things NICER is showing us about black holes. But first, let’s talk about black holes — how do they work, and where do they come from? There are two important types of black holes we’ll talk about here: stellar and supermassive. Stellar mass black holes are three to dozens of times as massive as our Sun while supermassive black holes can be billions of times as massive!

Stellar black holes begin with a bang — literally! They are one of the possible objects left over after a large star dies in a supernova explosion. Scientists think there are as many as a billion stellar mass black holes in our Milky Way galaxy alone!

Supermassive black holes have remained rather mysterious in comparison. Data suggest that supermassive black holes could be created when multiple black holes merge and make a bigger one. Or that these black holes formed during the early stages of galaxy formation, born when massive clouds of gas collapsed billions of years ago. There is very strong evidence that a supermassive black hole lies at the center of all large galaxies, as in our Milky Way.

Imagine an object 10 times more massive than the Sun squeezed into a sphere approximately the diameter of New York City — or cramming a billion trillion people into a car! These two examples give a sense of how incredibly compact and dense black holes can be.

Because so much stuff is squished into such a relatively small volume, a black hole’s gravity is strong enough that nothing — not even light — can escape from it. But if light can’t escape a dark fate when it encounters a black hole, how can we “see” black holes?

Scientists can’t observe black holes directly, because light can’t escape to bring us information about what’s going on inside them. Instead, they detect the presence of black holes indirectly — by looking for their effects on the cosmic objects around them. We see stars orbiting something massive but invisible to our telescopes, or even disappearing entirely!

When a star approaches a black hole’s event horizon — the point of no return — it’s torn apart. A technical term for this is “spaghettification” — we’re not kidding! Cosmic objects that go through the process of spaghettification become vertically stretched and horizontally compressed into thin, long shapes like noodles.

Scientists can also look for accretion disks when searching for black holes. These disks are relatively flat sheets of gas and dust that surround a cosmic object such as a star or black hole. The material in the disk swirls around and around, until it falls into the black hole. And because of the friction created by the constant movement, the material becomes super hot and emits light, including X-rays.  

At last — light! Different wavelengths of light coming from accretion disks are something we can see with our instruments. This reveals important information about black holes, even though we can’t see them directly.

So what has NICER helped us learn about black holes? One of the objects this instrument has studied during its time aboard the International Space Station is the ever-so-forgettably-named black hole GRS 1915+105, which lies nearly 36,000 light-years — or 200 million billion miles — away, in the direction of the constellation Aquila.

Scientists have found disk winds — fast streams of gas created by heat or pressure — near this black hole. Disk winds are pretty peculiar, and we still have a lot of questions about them. Where do they come from? And do they change the shape of the accretion disk?

It’s been difficult to answer these questions, but NICER is more sensitive than previous missions designed to return similar science data. Plus NICER often looks at GRS 1915+105 so it can see changes over time.

NICER’s observations of GRS 1915+105 have provided astronomers a prime example of disk wind patterns, allowing scientists to construct models that can help us better understand how accretion disks and their outflows around black holes work.

NICER has also collected data on a stellar mass black hole with another long name — MAXI J1535-571 (we can call it J1535 for short) — adding to information provided by NuSTAR, Chandra, and MAXI. Even though these are all X-ray detectors, their observations tell us something slightly different about J1535, complementing each other’s data!

This rapidly spinning black hole is part of a binary system, slurping material off its partner, a star. A thin halo of hot gas above the disk illuminates the accretion disk and causes it to glow in X-ray light, which reveals still more information about the shape, temperature, and even the chemical content of the disk. And it turns out that J1535’s disk may be warped!

Image courtesy of NRAO/AUI and Artist: John Kagaya (Hoshi No Techou)

This isn’t the first time we have seen evidence for a warped disk, but J1535’s disk can help us learn more about stellar black holes in binary systems, such as how they feed off their companions and how the accretion disks around black holes are structured.

NICER primarily studies neutron stars — it’s in the name! These are lighter-weight relatives of black holes that can be formed when stars explode. But NICER is also changing what we know about many types of X-ray sources. Thanks to NICER’s efforts, we are one step closer to a complete picture of black holes. And hey, that’s pretty nice!

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Extinct tree grows anew from ancient jar of seeds unearthed by archaeologists

by Stephen Messenger

“For thousands of years, Judean date palm trees were one of the most recognizable and welcome sights for people living in the Middle East — widely cultivated throughout the region for their sweet fruit, and for the cool shade they offered from the blazing desert sun.

From its founding some 3,000 years ago, to the dawn of the Common Era, the trees became a staple crop in the Kingdom of Judea, even garnering several shout-outs in the Old Testament. Judean palm trees would come to serve as one of the kingdom’s chief symbols of good fortune; King David named his daughter, Tamar, after the plant’s name in Hebrew.

By the time the Roman Empire sought to usurp control of the kingdom in 70 AD, broad forests of these trees flourished as a staple crop to the Judean economy — a fact that made them a prime resource for the invading army to destroy. Sadly, around the year 500 AD, the once plentiful palm had been completely wiped out, driven to extinction for the sake of conquest.

In the centuries that followed, first-hand knowledge of the tree slipped from memory to legend. Up until recently, that is.

During excavations at the site of Herod the Great’s palace in Israel in the early 1960’s, archeologists unearthed a small stockpile of seeds stowed in a clay jar dating back 2,000 years. For the next four decades, the ancient seeds were kept in a drawer at Tel Aviv’s Bar-Ilan University. But then, in 2005, botanical researcher Elaine Solowey decided to plant one and see what, if anything, would sprout.

“I assumed the food in the seed would be no good after all that time. How could it be?“ said Solowey. She was soon proven wrong.

Amazingly, the multi-millennial seed did indeed sprout — producing a sapling no one had seen in centuries, becoming the oldest known tree seed to germinate.

Today, the living archeological treasure continues to grow and thrive; In 2011, it even produced its first flower — a heartening sign that the ancient survivor was eager to reproduce. It has been proposed that the tree be cross-bred with closely related palm types, but it would likely take years for it to begin producing any of its famed fruits. Meanwhile, Solowey is working to revive other age-old trees from their long dormancy.”

***Does anyone in the know have any comments?

(Source: Tree Hugger)

New type of star system? Mysterious radio signal puzzles astronomers

by Laura Nicole Driessen

Meerkat telescope. Sotiris Sanidas, Author provided

After observing a part of the sky near the Southern Constellation of Ara for about two months using MeerKAT, a radio telescope based in the Karoo desert in South Africa, our team of scientists noticed something strange. The radio emission of an object brightened by a factor of three over roughly three weeks.

Intrigued, we continued watching the object and followed this up with observations from other telescopes. We discovered that the unusual flare came from a binary star system – two stars orbiting each other – in our own galaxy. The finding, published in the Monthly Notices of the Royal Astronomical Society, has, however, turned out to be very difficult to explain.

Keep reading

TRAILER: “FANTASTIC PLANET” (1973)

Also known as “la Planète sauvage”, this film is an animated story that follows the relationship between the small human-like Oms and their blue-skinned oppressors, the Draags, who rule the planet of Ygam. While the Draags have long kept Oms as illiterate pets, this hierarchy shifts after an Om boy becomes educated, thanks to a young female Draag. This leads to an Om rebellion, which weakens the Draag control over their race. Will the Oms and the Draags find a way to coexist? Or will they destroy each other?

TRAILER: “TIME MASTERS (LES MAÎTRES DU TEMPS)” (1982)

This animated science fiction feature film was directed by René Laloux and Tibor Hernádi but most notably - designed by the artist Mœbius. It is based on Stefan Wul’s 1958 science fiction novel L'Orphelin de Perdide (The Orphan of Perdide).

It’s about a boy, Piel, who is stranded on the desert planet Perdide, where giant killer hornets live. He awaits rescue by the space pilot Jaffar, the exiled prince Matton, his sister Belle and Jaffar’s old friend Silbad - who are all trying to reach Perdide and save Piel before it is too late.

If you’ve seen this film,  you’ve probably seen the English language dubs by the BBC in 1987 or 1991 called Time Masters.

This is a super rare film that you can find on DVD, but usually used, and pretty expensive.

TRAILER: “NO BLADE OF GRASS” (1970)

This adaptation of John Christopher’s novel “The Death of Grass” was co-written, directed and produced by Cornel Wilde. It’s a British/American co-production starring Nigel Davenport, Jean Wallace, and John Hamill. 

It follows the survivors of a plague that has hit London in the not too distant future - at least the future not too distant from 1970. When London is overwhelmed by food riots caused by a global famine, a man tries to lead his family to safety in Westmorland. The family is joined by a violent man and his girlfriend as they try to leave before martial law and complete anarchy ensue.

As we’ve been discussing in our ongoing podcast series “Sci Fi Time Capsule”, there’s no era of science fiction film quite like the 1970s.

“No Blade of Grass” is a bit of a rare film, but you can buy it on DVD or stream  it on Apple TV,  Amazon Prime Video, and The Criterion Channel.

TRAILER: “AFTER WE LEAVE” (2019)

Written and Directed by Aleem Hossain, “After We Leave” is a gritty sci-fi feature film about a man who has a once-in-a-lifetime chance to emigrate off Earth… only if he can find his estranged wife and convince her to come with him.

Winner: Best Feature Film at Sci Fi London Winner: Best Director at Berlin Sci Fi Film Fest

An Earth-sized planet found in the habitable zone of a nearby star

by Ravi Kumar Kopparapu

An artist’s impression of an exoplanet in the habitable zone around a star. Credits: ESA/Hubble, M. Kornmesser

A few months ago a group of NASA exoplanet astronomers, who are in the business of discovering planets around other stars, called me into a secret meeting to tell me about a planet that had captured their interest. Because my expertise lies in modeling the climate of exoplanets, they asked me to figure out whether this new planet was habitable – a place where liquid water might exist.

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Could invisible aliens really exist among us? An astrobiologist explains

by Samantha Rolfe

They probably won’t look anything like this. Martina Badini/Shutterstock

Life is pretty easy to recognise. It moves, it grows, it eats, it excretes, it reproduces. Simple. In biology, researchers often use the acronym “MRSGREN” to describe it. It stands for movement, respiration, sensitivity, growth, reproduction, excretion and nutrition.

But Helen Sharman, Britain’s first astronaut and a chemist at Imperial College London, recently said that alien lifeforms that are impossible to spot may be living among us. How could that be possible?

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Hubble fortuitously discovers a new galaxy in the cosmic neighborhood

Astronomers using the NASA/ESA Hubble Space Telescope to study some of the oldest and faintest stars in the globular cluster NGC 6752 have made an unexpected finding. They discovered a dwarf galaxy in our cosmic backyard, only 30 million light-years away. The finding is reported in the journal Monthly Notices of the Royal Astronomical Society: Letters.

An international team of astronomers recently used the NASA/ESA Hubble Space Telescope to study white dwarf stars within the globular cluster NGC 6752. The aim of their observations was to use these stars to measure the age of the globular cluster, but in the process they made an unexpected discovery.

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Faint starlight in Hubble images reveals distribution of dark matter

Astronomers using data from the NASA/ESA Hubble Space Telescope have employed a revolutionary method to detect dark matter in galaxy clusters. The method allows astronomers to “see” the distribution of dark matter more accurately than any other method used to date and it could possibly be used to explore the ultimate nature of dark matter. The results were published in the journal Monthly Notices of the Royal Astronomical Society.

In recent decades astronomers have tried to understand the true nature of the mysterious substance that makes up most of the matter in the Universe – dark matter – and to map its distribution in the Universe. Now two astronomers from Australia and Spain have used data from the Frontier Fields programme of the NASA/ESA Hubble Space Telescope to accurately study the distribution of dark matter.

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Tabby's Star, not an Alien megastructure is the cause of dimming of the 'most mysterious star in the universe'

A team of more than 200 researchers, including Penn State Department of Astronomy and Astrophysics Assistant Professor Jason Wright and led by Louisiana State University’s Tabetha Boyajian, is one step closer to solving the mystery behind the “most mysterious star in the universe.” KIC 8462852, or “Tabby’s Star,” nicknamed after Boyajian, is otherwise an ordinary star, about 50 percent bigger and 1,000 degrees hotter than the Sun, and about than 1,000 light years away. However, it has been inexplicably dimming and brightening sporadically like no other. Several theories abound to explain the star’s unusual light patterns, including that an alien megastructure is orbiting the star.

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Black holes ruled out as universe's missing dark matter

For one brief shining moment after the 2015 detection of gravitational waves from colliding black holes, astronomers held out hope that the universe’s mysterious dark matter might consist of a plenitude of black holes sprinkled throughout the universe.

University of California, Berkeley, physicists have dashed those hopes.

Based on a statistical analysis of 740 of the brightest supernovas discovered as of 2014, and the fact that none of them appear to be magnified or brightened by hidden black hole “gravitational lenses,” the researchers concluded that primordial black holes can make up no more than about 40 percent of the dark matter in the universe. Primordial black holes could only have been created within the first milliseconds of the Big Bang as regions of the universe with a concentrated mass tens or hundreds of times that of the sun collapsed into objects a hundred kilometers across.

The results suggest that none of the universe’s dark matter consists of heavy black holes, or any similar object, including massive compact halo objects, so-called MACHOs.

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This astrophysicist is unlocking  the secrets of dark matter

by Daryle Lockhart

Nico Cappelluti is an assistant professor in the Physics Department and an astrophysicist at the University of Miami. As such, he studies the sky. He is most intrigued by the cosmic phenomena of supermassive black holes, the nature of dark matter, and the very bright light source found at the center of many galaxies - active galactic nuclei.

Recently, Cappelluti published findings in The Astrophysical Journal entitled, “Searching for the 3.5 keV line in the deep fields with Chandra: the 10 MS observations”. His findings could give insight into a subject astrophysicists have been investigating for decades: What is dark matter and where does it come from?

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