Category: Deep Space

Astronomers report latest detection of radio bursts coming from space

The recent detection reflects lower frequencies than what astronomers have reported in the past.

Fast Radio Bursts (FRBs) are some of the most explosive events in the Universe. They can generate as much energy as 500 million Suns in milliseconds, and there could be as many as one happening every second, writes Fiona Macdonald for Science Alert. Now, astronomers report detection of another FRB hitting Earth from an unknown source. This particular radio burst falls within the lower end of the spectrum, within the 50 megahertz frequency range, nearly 200 MHz lower than any other signal scientists have detected before. FRBs are incredibly mysterious, astronomers don’t yet know what’s causing them.

Although one of the signals detected has sent out multiple FRBs from the same location—allowing scientists to pinpoint where in the Universes it’s coming from—they still aren’t certain what caused it. Most signals are only detected once, making it difficult for astronomers to determine the source. The recent FRB was detected on July 25, 2018 and reported in The Astronomer’s Telegram. It has been named FRB 180725A, and was caught by an array of radio telescopes in British Columbia, Canada. The Astronomer’s Telegram is a bulletin board of observations posted by accredited researchers, however these observations haven’t been peer reviewed and verified by independent teams. Still, the results make it the first detection of a FRB under 700 MHz. “These events have occurred during both the day and night, and their arrival times are not correlated with known on-site activities or other known sources,” stipulates Patrick Boyle, project manager for the Canadian Hydrogen Intensity Mapping Experiment (CHIME).

Hypotheses abound for the source of FRBs, including black holes, imploding pulsars, and magnetars emitting giant flares to name a few. According to a Harvard physicist, it’s not impossible that FRBs could be engines firing on alien spaceships. While scientists are working to discover the source, they have learned that FRBs cover a spread of frequencies, they seem to be coming from billions of light-years away, and the source of the bursts has to be very energetic. Solving this mystery could help further understanding of the origin of the Universe.

UV light shows which exoplanets may harbor life

A new study shows that UV light is key in providing the building blocks needed for life.

Researchers from the University of Cambridge and the Medical Research Council Laboratory of Molecular Biology have identified a group of exoplanets with the same chemical conditions that may have once allowed life to exist on Earth, according to a new study published in the journal Science Advances.

In the research, the team found that ultraviolet (UV) light sparks a series of chemical reactions that produce the essential building blocks needed to create life.

Using that idea, they then identified multiple planets that both sit inside their star’s habitable zone and get enough UV light from their host star to spark such reactions.

It is those distant worlds where life is most likely be found.

The team began the study by theorizing that cyanide helped life exist on early Earth. They argued that carbon from meteorites slammed into our planet millions of years ago and interacted with nitrogen to create hydrogen cyanide.

The cyanide then rained to the surface, where it reacted with the sun’s UV light and generated the first building blocks for RNA.

After using UV lamps to recreate such reactions in the lab, the team managed to build many of life’s essential elements, including lipids, amino acids, and nucleotides.

From there, researchers ran a series of experiments to see how quickly the mix of UV light, water, and hydrogen cyanide or sulphite ions can create those key building blocks. They then repeated the process without light.

That showed, while stars around the same temperature as our sun are able to create the right amount of light for life’s building blocks, cool stars cannot.

As a result, the team believes the only planets worth searching for life at are ones in the so-called abiogenesis zone — a region where planets get both liquid water and enough light to activate basic chemistry.

“The thing that you know best about any exoplanet system is the star,” lead author Paul Rimmer, an astrochemist at the University of Cambridge, told Space.com. “So, that seemed like a natural thing to start with.”

While only a few known exoplanets sit in that zone, the team hopes future technology will be able to track down more hanging throughout the cosmos.

“This work allows us to narrow down the best places to search for life,” added Rimmer, according to Phys.org. “It brings us just a little bit closer to addressing the question of whether we are alone in the universe.”

Intermediate black holes can bring stars back to life

A new study reveals that medium-sized black holes are able to briefly reignite dead stars.

If a dead star passes close to a medium-sized black hole it can come back to life for a brief moment, according to a new study published on the preprint site Arxiv.org and accepted for publication in The Astrophysical Journal.

This finding comes from a group of international astronomers, who performed a series of computer simulations that revealed what happens when a burned-out stellar corpse — also called a white dwarf — moves by an intermediate-mass black hole.

After analyzing the data, researchers found that the hole’s strong gravity can stretch and distort the dwarf in such a way that the elements inside its core reignite for a few seconds.

Those so-called “tidal disruption events” can also create gravitational waves that, while not detectable by current technology, could be picked up for study in the future.

The new study is important for a few reasons, but one of the biggest is that it sheds light on medium-sized black holes, which have proven difficult to study. Though many smaller and larger holes are on record, the middle ones are not easy to pin down. As a result, the more information on them, the better.

“It is important to know how many intermediate mass black holes exist, as this will help answer the question of where supermassive black holes come from,” study co-author Chris Fragile, a professor of physics and astronomy at the College of Charleston in South Carolina, according to Space.com.“Finding intermediate mass black holes through tidal disruption events would be a tremendous advancement.”

Another reason the finding is important is because it shows how the sun could die in the distant future. Every star that begins its life with about 8 solar masses or fewer will end up as a superdense white dwarf, and analyzing our star in light could provide more insight into the universe’s larger mechanisms.

Scientists directly observe growth of infant exoplanet

Observation will give scientists new insights into the early stages of planet formation.

For the first time ever, scientists have observed a baby exoplanet in the process of growing by accreting material from the disk surrounding the star it orbits.

Using adaptive optics on the 6.5-meter Magellan Clay Telescope in Chile, a team of astronomers led by Kevin Wagner of the University of Arizona, Amherst College, NExSS and Earths in Other Solar Systems studied the 10-million-year old parent star, an orange dwarf known as PDS 70, located 370 light years from Earth.

Unlike most planets in the process of forming, which can be imaged only indirectly as gaps in the circumstellar disks surrounding young stars, PDS 70b has been seen directly as it accretes material from the disk surrounding its star.

“These disks around young stars are the birthplaces of planets, but so far, only a handful of observations have detected hints of baby planets in them. The problem is that until now, most of these planet candidates could just have been features in the disk,” said Miriam Keppler of the Max Planck Institute for Astronomy in Heidelberg, Germany, and leader of the group that initially discovered PDS 70b.

The researchers observed the system in hydrogen alpha and similar wavelengths on two nights last May. They detected hydrogen alpha emissions at the site of the planet, indicating hot hydrogen gas is falling onto it, a clear sign that it is still accreting material.

Even though it is a baby planet still in the process of forming, PDS 70b is already larger than Jupiter. Scientists estimate it has completed 90 percent of its growth and that it likely accreted material at a much faster rate in its early years than it is doing so now.

PDS 70b’s surface temperature is estimated to be approximately 1,382 degrees Fahrenheit (1,000 degrees Celsius), and its atmosphere is thought to be cloudy.

Being able to observe the process of a planet growing by gathering materials from a star’s circumstellar disk will give scientists new insight into the planet formation process.

The research team’s findings have been published in The Astrophysical Journal Letters.

Scientists conduct experiments to explain the origins of our Universe

Experiments searching for a solution to one of physics’ biggest mysteries have delivered their first rounds of results.

Right now there are four major experiments being conducted around the world, hunting for signs of barely-detectable particles undergoing rare changes. In an article for Science Alert, Mike Mcrae explains why matter shouldn’t exist based on our current understanding of physics.

As subatomic particles cooled out of the radiation following the first moments of Universe, they took one of two forms—matter and antimatter. Therein lies the paradox, however, because these mirror-opposite objects also cancel out in a flash of energy when they meet again. So, if both types of particles are created next to one another in equal amounts, the math says we should have nothing left over. However, most visible objects are made from just one kind of particle—matter.

Neutrinos (a type of neutrally charged particle) may provide answers to this paradox. Neutrinos are a million times lighter than an electron, meaning they barely interact with other particles. Properties of these ‘ghost particles’ may mean that neutrinos are matter and anti-matter in one. Exploring neutrinos may be the pathway to explaining why our universe didn’t immediately cancel itself out.

Experiments are taking place to explore this mystery. The Cryogenic Underground Observatory for Rare Events (CUORE) at Gran Sasso Laboratory in Italy is based on just a flash in one of 1,000 crystals of tellurium dioxide to advertise the moment of neutrinoless double beta decay. They expect to see only five decays in the next five years. CUORE member, Lindley Winslow told Jennifer Chu at MIT News that it’s a very rare process.   “If observed, it would be the slowest thing that has ever been measured,” she said. A second experiment at Gran Sasso is using isotope germanium-76 instead. They have less material to catch the decay, but the whole set-up is proving to be extremely sensitive, reducing the risk of missing the event if it happens.

In the U.S. at the Sanford Underground Research Facility, collaborators are working on an experiment called the MAJORANA Demonstrator. All of these experiments are looking for the conservation of a particular quantum number as pairs of neutrons decay within certain isotopes. To-date, the results from these experiments have narrowed the field of places to search for neutrinos.

Exoplanet habitability connected to host star’s light

Ability to produce life’s building blocks depends on level of ultraviolet light received from the host star.

The chances of life developing on rocky, Earth-like exoplanets may be determined by both the type and intensity of the light emitted by the planets’ host stars, according to a new study published in the journal Science Advances.

A group of scientists at Cambridge University and at the Medical Research Council Laboratory of Molecular Biology (MRC LMB) identified a list of rocky exoplanets whose stars emit sufficient ultraviolet light for the chemical reactions that produce the building blocks of life to occur.

On Earth, ultraviolet light from the Sun started this series of chemical reactions.

All the exoplanets the researchers identified are located in their stars’ habitable regions, with temperatures that allow liquid water to exist on their surfaces.

“This work allows us to narrow down the best places to search for life,” said Paul Rimmer of both Cambridge University’s Cavendish Laboratory and MRC LMB. “It brings us just a little bit closer to addressing the question of whether we are alone in the universe.”

The latest study is part of an ongoing collaboration between the two above institutions combining exoplanet research with organic chemistry. It builds on a 2015 paper, also published in Science Advances, in which scientists theorized that meteorites containing carbon impacted early Earth, releasing that carbon, which then interacted with atmospheric nitrogen to produce hydrogen cyanide.

Although hydrogen cyanide itself is toxic to life, its interaction with various elements on Earth’s surface via power from ultraviolet sunlight generated the building blocks of RNA, theorized to be the first molecule of life to carry information. RNA is closely related to DNA, the self-replicating material that carries genetic information in practically all organisms.

In a series of laboratory experiments, the researchers exposed water containing hydrogen cyanide and hydrogen sulphite ions to ultraviolet light and to no light to find out how quickly the building blocks of life would form.

“There is a chemistry that happens in the dark: it’s slower than the chemistry that happens in the light, but it’s there. We wanted to see how much light it would take for the light chemistry to win out over the dark chemistry,” explained Didier Queloz, also of Cavendish Laboratory.

Under darkness, the hydrogen cyanide and hydrogen sulphite produced an inert compound that could not form the building blocks of life. However, under ultraviolet light, they did produce these building blocks.

The scientists then compared the light chemistry used in the experiment to the ultraviolet light of various stars as well as the amount of light available to those stars’ planets and found that stars with roughly the same temperature as our Sun emitted sufficient light to form life’s building blocks.

Planets with temperatures that allow liquid water on their surfaces that also receive the appropriate amount of ultraviolet light to start this chemical process were designated as being in the abiogenesis zone.

 

Spiral galaxies’ outskirts host massive stellar black holes

Discovery will help scientists pinpoint more potential sources of gravitational waves.

The outer regions of spiral galaxies can host massive black holes formed when giant stars ended their lives in supernova explosions, according to a new study led by Sukanya Chakrabarti of the Rochester Institute of Technology (RIT) School of Physics and Astronomy.

Chakrabarti’s team analyzed data from the Lick Observatory Supernova Search, which compared the rates of supernova explosions in the outskirts of spiral galaxies with the rates of those that occur in smaller dwarf or satellite galaxies.

According to the Lick data, the supernova rates are comparable for the outskirts of both types of galaxies, with each having an average of two every millennium.

Knowing that these locations host black holes created by the core collapse of massive stars is a boon to scientists who study gravitational waves, which are produced by black hole collisions.

Dwarf and satellite galaxies are known to have low levels of elements heavier than hydrogen and helium, a condition ideal for both the formation and merger of stellar mass black holes. The new study, about which a paper will be published in Astrophysical Journal Letters, reveals similar favorable conditions for black holes can also be found in the outer regions of spiral galaxies.

“If these core collapse supernovae are the predecessors to the binary black holes detected by LIGO (Laser Interferometer Gravitational-wave Observatory), then what we’ve found is a reliable method of identifying the host galaxies of LIGO sources,” Chakrabarti noted.

“Because these black holes have an electromagnetic counterpart at an earlier stage in their life, we can pinpoint their location in the sky and watch for massive black holes.”

The electromagnetic counterparts to which Chakrabarti referred are the dying massive stars whose cores collapse before they explode as supernovae. As these stars die, they produce bright signatures in the electromagnetic spectrum.

Additional surveys of the outskirts of both dwarf and spiral galaxies will likely help scientists detect more LIGO events, Chakrabarti said.

Andromeda galaxy likely swallowed Milky Way’s sibling

Researchers discovered evidence that Andromeda likely collided with the Milky Way’s sister galaxy billions of years ago.

Scientists from the University of Michigan have found evidence that the nearby Andromeda galaxy clashed with and devoured the Milky Way’s long-lost sibling M32p, a new study in Nature Astronomy reports.

The Milky Way and Andromeda are linked because they are two of the largest galaxies in our small section of the universe. However, in the new study astronomers found that Andromeda once devoured the third largest member of the family roughly 2 billion years ago.

“Astronomers have been studying the Local Group — the Milky Way, Andromeda and their companions — for so long,” said study co-author Eric Bell, a professor of astronomy at the University of Michigan, according to Space.com. “It was shocking to realize that the Milky Way had a large sibling, and we never knew about it.”

The team made this new discovery by using computer simulations to reveal that almost all of the stars in the outer reaches of Andromeda’s “halo” — the roughly spherical region surrounding the galaxy’s disk — came from a single event.

That is important because scientists used that information to properly infer the properties of the largest of those long-dead galaxies.

That process, combined with recently created models, enabled the team to properly date the merger to roughly 2 billion years ago. In addition, they also managed to reconstruct some details from the long-dead galaxy.

That showed M32p was roughly 20 times the size of any galaxy the Milky Way has ever merged with. In addition, scientists believe that Andromeda’s satellite galaxy M32 — which is one of the most compact galaxies in the universe — is likely made up of the remains from M32p.

The timing of the ancient merger is important because it reinforces what scientists understand about galaxy formation. It also matches up with previous research that Andromeda merged with another large galaxy between 1.8 and 3 billion years ago.

In that way, the finding may help scientists better understand the mechanisms behind galaxy mergers and shed light on the way they evolved over time.

“The Andromeda Galaxy, with a spectacular burst of star formation, would have looked so different 2 billion years ago,” added Bell, according to Phys.org.

Dwarf galaxy mergers generate star formation

Dwarf galaxies have abundant levels of hydrogen gas, the fuel that drives star birth.

Dwarf galaxies such as the Large and Small Magellanic Clouds have abundant hydrogen gas, which plays a key role in star formation.

When two dwarf galaxies merge with one another or one dwarf galaxy merges with a larger, parent galaxy, this hydrogen gas is dispersed within the new combined galaxy, where it acts as fuel to generate the birth of new stars.

“You have this enormous reserve of star formation fuel sitting there ready to be stripped by another system,” explained Mary Putnam of Columbia University, who took part in a study on the role of hydrogen gas in galaxy mergers.

Both the Large and Small Magellanic Clouds are dwarf galaxy satellites of the much larger Milky Way. The two were in the process of  merging when they were gravitationally pulled into the Milky Way’s orbit. Between them, there is enough hydrogen gas to replenish around half of the Milky Way’s star-formation fuel.

Much dimmer than their larger spiral counterparts, dwarf galaxies are filled with swirling hydrogen gas.

Led by then-Columbia graduate student Sarah Pearson, now at the Flatiron Institute‘s Center for Computational Astrophysics, a team of researchers observed two distant dwarf galaxies, NGC 4490 and NGC 4485, both located approximately 23 million light years away, to learn more about the role hydrogen gas in dwarf galaxies plays in creating new stars. NGC 4490 is several times larger than its partner.

Unlike the Magellanic Clouds, these two dwarf galaxies are not bound to a larger spiral galaxy like the Milky Way, so scientists can observe their merging without the influence of a larger parent galaxy.

By inputting data about the two dwarf galaxies into a computer simulation, the researchers modeled their merger, focusing on the subsequent expansion of their hydrogen gas over five billion years. By that time, “tails” of hydrogen gas stretched more than a million light years.

“After five billion years, 10 percent of the gas envelope still resides more than 260,000 light years from the merged remnant, suggesting it takes a very long time before all the gas falls back to the merged remnant,” Pearson said.

Over time, the gas clouds became more and more extended, thinning them out and making it easier for any nearby large galaxies to absorb them. This phenomenon likely makes it easy for the Milky Way to absorb gas from the Magellanic Clouds.

To better understand these dynamics, the researchers plan to study other pairs of dwarf galaxies.

A paper on the study has been published in Monthly Notices of the Royal Astronomical Society.

More mini-moons may be found in the future, study reports

Astronomers believe that new technology could lead to the discovery of more mini-moons, a process that could shed more light on asteroid composition.

A of team of international astronomers believe new space technology could be used to track and monitor mini-moons, according to new research published in the journal Frontiers in Astronomy and Space Sciences.

Nearly 12 years ago scientists detected a tiny asteroid known as 2006 RH120. They took interest in the small space rock because it was the first-known natural object to orbit Earth other than the moon.

Though scientists predicted they would find more of those “mini-moons” — asteroids that measure just 39 to 79 inches across and get temporarily caught in the Earth’s orbit — in the future, they have had no such luck. The team in the recent study states that is because current technology is not quite there.

Mini-moons are extremely small and move incredibly fast. That combination makes it so current asteroid surveys are not able to detect them.

“Mini-moons can provide interesting science and technology testbeds in near-Earth space,” said lead author Robert Jedicke, a researcher at the University of Hawaii, in a Newsweek. “These asteroids are delivered towards Earth from the main asteroid belt between Mars and Jupiter via gravitational interactions with the Sun and planets in our solar system. The challenge lies in finding these small objects, despite their close proximity.”

The reason mini-moons are so important is because they could one day help scientists gain a better understanding of both asteroids and the Earth-moon system.

Currently, researchers do not fully know what asteroids are made of. Mini-moons could give them insight into that make-up and potentially allow better analysis of deep space rocks. New technology will make that happen.

For instance, the upcoming Large Synoptic Survey Telescope (LSST) — set to be operational in a few years — could use its large mirror and wide field camera to pick up mini-moons traveling through space.

“I hope that humans will someday venture into the solar system to explore the planets, asteroids and comets—and I see mini-moons as the first stepping stones on that voyage,” added Jedicke, according to Phys.org

The tiny bodies could be the perfect platform for companies to develop or test both asteroid mining and planetary defense technologies as well.