Connect with us

Space

Discovery of 62 new moons around the planet Saturn

Published

on

Discovery of 62 new moons around the planet Saturn

Discovery of 62 new moons around the planet Saturn. Scientists discovered 62 new moons around the planet Saturn, bringing the total number of moons to 145. This is the most number of moons for a planet in the solar system.

Discovery of 62 new moons around the planet Saturn

Jupiter’s short but glorious reign as the planet with the most moons in the Solar System ended this week as scientists confirmed the discovery of 62 new moons orbiting Saturn, bringing the ringed planet’s total to 145.

This leap put Saturn ahead of Jupiter, which has 95 confirmed moons so far. In December, 12 new moons were officially confirmed around Jupiter, which eclipsed Saturn’s position. Saturn is now the first and only planet in the solar system to have more than 100 known moons, according to University of British Columbia (UBC) researchers who helped make the new discoveries.

Read More: James Webb’s look at one of the brightest early galaxies

A group of international researchers made this discovery using data from the Canada-France-Hawaii telescope between 2019 and 2021. By analyzing a series of consecutive images taken in three-hour observation windows, the team identified 62 moons that were previously too small or too dim to detect. Some moons were only 1.6 miles (2.5 km) wide.

All 62 newly discovered moons are “atypical moons,” meaning they follow elliptical orbits around their host planet, often moving in the opposite direction to Saturn’s rotation. According to the researchers, many of these small, unusual moons are clustered together in similar anti-orbital orbits, suggesting that they may have originated from a larger moon that broke up millions of years ago.

Professor Brett Gladman, professor of astronomy, says: “As we use the maximum power of modern telescopes, we are finding increasing evidence that a medium-sized anti-Saturn-orbiting moon exploded about 100 million years ago. Is.

The new moons are expected to be identified later this month by the International Astronomical Union, a group of more than 12,000 scientists responsible for determining celestial bodies.

Space

What is the farthest thing we can see in the sky?

Published

on

By

What is the farthest thing we can see in the sky?
To the unaided human eye, the night sky is magnificent and stunning with more than 9,000 individual points of light, but this view covers only a small part of the universe. So what is the farthest thing we can see in the sky?

What is the farthest thing we can see in the sky?

What is the farthest thing we can see in the sky? The closest visible star system to us is Alpha Centauri, which is about 4.25 light years away from Earth. The closest star in this triple star system is Proxima Centauri, but because it is considered a red dwarf, it is too faint to be seen without a telescope.

According to Space.com, the farthest star visible to the naked eye is V762 Cas, a variable star located 16,000 light-years away. Although the star is probably 100,000 times brighter than the Sun, this great distance means that it is ideally at the edge of the average human’s night vision.

distant galaxies
A field of distant galaxies captured by the James Webb Space Telescope.

All the stars we can see without a telescope are much bigger than the Sun. Stars like the Sun and smaller stars are too faint to overcome the distance between them and the Earth and are therefore not visible to us. Thus, there are about 9,000 visible stars and over a million invisible stars at our distance to V762 Cas.

While V762 Cas is the most distant star we can see with the naked eye, it is not the most distant object we can see without a telescope. This honor goes to the Andromeda galaxy.

The nearest star system visible to us is Alpha Centauri

When we look at the Andromeda Galaxy, which contains more than a trillion stars, it appears to our eyes as a fuzzy blob about the size of an open fist. When you look at Andromeda, you get light that began its journey more than 2.5 million years ago.

Some flashes and explosions reach high levels of brightness and are temporarily visible even from great distances. For example, in 2008 the gamma-ray burst GRB 080319B was visible to the naked eye for about 30 seconds, even though it was more than 7.5 billion light-years away. This means that the solar system had not yet formed when the light from this gamma-ray burst first began its journey.

When Galileo perfected the astronomical telescope in the early 1600s, a new world opened up to our eyes. Telescopes allow us to see fainter objects because they can collect more light and magnify the images.

Yet even with the most advanced ground-based and space-based telescopes and the most comprehensive surveys, we have managed to map less than 3% of all the stars within the Milky Way and less than 1% of the galaxies in the visible universe. The most distant galaxies are not yet within our reach; They are so faint and small that we cannot detect them.

The Milky Way
The James Webb Space Telescope’s near-infrared camera shows a region 50 light-years across from the Milky Way’s dense center. According to estimates, 500,000 stars shine in this region of the arc, as well as some objects that have not yet been identified.

Nature has provided us with a little trick that we can sometimes use to see deeper into the universe. When light from a distant star or galaxy passes through a massive cluster, the cluster’s gravity can magnify the image (in some cases 10,000 times or more).

It is through this phenomenon of gravitational convergence that astronomers have been able to identify the farthest known star, Irondale, which is currently more than 28 billion light years away from us. Irondale star reached the stage of the universe 900 million years after the Big Bang and was one of the first generations of stars that appeared in the universe.

Read More: Planet-eating stars are surprisingly common in the universe

The most distant object we can see without a telescope is the Andromeda Galaxy

Using a technique similar to gravitational convergence, astronomers used the James Webb Space Telescope to accurately measure the distance from Earth to the most distant known galaxy, JADES-GS-z13-0. This galaxy is now more than 33.6 billion light-years away and was formed when our universe was 400 million years old.

Beyond that, we can still see cosmic objects, but we have to use other wavelengths of light to see them.

In the microwave range, we are surrounded by the glow of cosmic background radiation, the light produced when the universe was 380,000 years old and transformed from plasma to neutral gas. This light has since flooded the universe and is almost at the edge of the visible universe.

Astronomers speculate that there are even older signals. For example, strange processes in the first moments of the Big Bang produced a shower of ghost-like particles known as neutrinos, and the search for them continues.

Even stranger processes in the first second of the Big Bang probably flooded the universe with gravitational waves. Proposed missions like the Big Bang Observer might pick up faint traces of this residual signal, in which case these signals would be the furthest thing we could detect.

Continue Reading

Space

Planet-eating stars are surprisingly common in the universe

Published

on

By

Planet-eating stars
Planet-eating stars are surprisingly common in the universe. Astronomers have found out by examining dozens of twin stars that apparently one of every 12 stars in the world has swallowed its planet.

Planet-eating stars are surprisingly common in the universe

Planet-eating stars are surprisingly common in the universe. Is our solar system a normal system or a unique one? This mystery is one of the biggest questions in astronomy, and scientists have come a little closer to the answer by examining more than 5,500 exoplanets that have been discovered around other stars. However, the answer to the puzzle is confounded by a fairly significant problem: some stars eat their planets, making learning what is considered “normal” for planetary systems a little more laborious.

Now, according to a new study published in the journal Nature, planet-swallowing may not be an unexpected event, but a common one in the cosmos. An international team of scientists looked at dozens of closely related pairs of twin stars (stars that were born at the same time from the same protostellar cloud). It was expected that both twin stars would have started their lives with basically the same compositions, But scientists have found that this was not always the case. In 8 percent of those twin pairs, one of the stars visibly ejects masses of elements typically found in planets.

Gravitational perturbations can regularly fling rocky worlds toward their stars, even in mature systems.

Astronomers have previously studied stellar twins to discover greedy planet-eating stars, But the findings were never so conclusive. Yuan Sen Ting, an astrophysicist at the Australian National University and one of the authors of the study refers to the high strength of the observed signals and describes the study’s finding as a low estimate.

The authors of the study suspect that the indigestion observed in the stars reflects a change in their dietary intake during adulthood; That is, when unstable orbital paths regularly send planets into the star’s hellish embrace. This suggests that gravitational perturbations, possibly from passing stray stars or migrating gas giants, can regularly throw rocky worlds toward their stars, even in mature systems.

Planet-eating stars are surprisingly common in the universe

The recent discovery also offers a more efficient way to search for exoplanets. Lorenzo Spina, an astrophysicist at the Padua Astronomical Observatory in Italy, to Scientific American “In the future, we could use the abundance of chemicals in stars to select priority targets when searching for planets,”. Spina believes that stars that lack signs of planet-swallowing are more likely to host a system similar to our own cosmic neighborhood.

In the vast field of research to understand the life and death of planets, finding such strong evidence of their being swallowed by their stars is an explanation for an age-old puzzle. For years, stars exhibiting strange rotations, unusual flares, or special chemical compositions have puzzled astronomers. Stars that are strangely refractory elements (iron and even metals more resistant to evaporation) seem suspicious objects; Because such durable materials often make their way to planets.

But by examining individual stars, it was difficult to tell whether the star had turned its planet into its meal or formed from a unique interstellar cloud. In contrast, stellar twins born at the same time from the same cloud are ideal for unraveling the mystery. “Just like many sociological studies, twins are surprising,” says Ting. Because by going to them, you eliminate all other confounding factors.” If one of those twins has a high compositional similarity to its protostellar cloud, but its stellar sibling contains large amounts of silicon and iron, the latter has most likely returned from a planet-swallowing feast.

The research team used the European Space Agency’s Gaia space telescope to obtain the maximum sample size. This space observatory is particularly good at tracking the journey of billions of rotating stars in the Milky Way. In fact, Gaia is such a useful tool that its data can be used to retrace a star’s long-term motions and reveal its close relationship with other distant stars. In this way, the researchers identified 91 pairs of twin stars, many of which were not so dissimilar to our Sun.

The researchers then recorded the stars’ chemical composition using large ground-based telescopes and identified 21 elements commonly associated with planets, including carbon, oxygen, silicon, iron, nickel, and zinc. “We can detect all the subtle differences in these different elements,” says Fan Liu, an astronomer at Monash University in Australia and one of the study’s authors. Liu and his colleagues observed signs of a planetary engulfment event in 8 percent of the pairs.

Planet-eating stars are surprisingly common in the universe

The Earth may exist simply because the Sun did not want to swallow its planets

Many questions remain unanswered; Like what kinds of planets tend to be eaten by their stars, and how to be sure if any star has completely avoided swallowing its own planets.

But are 8% or more of all stars likely to be planet eaters? Circumstantial evidence inconclusively points to the same, But evaluating such a rate is very challenging. Even a sample of 91 stellar twins is tiny compared to the hundreds of billions of stars in the Milky Way, let alone countless stars in other galaxies.

What do the study’s findings say about our middle-aged Sun? Our star has no known fraternal twin, But numerous studies of similar stars elsewhere in the galaxy suggest that the Sun is not particularly enriched in refractory elements. In fact, it even seems that the sun is depleted of these elements, and this feature makes it appear unusual in another aspect. “The further we look into our own solar system, the weirder it gets,” Kane says.

According to Spina, we have discovered that there is a huge variety of planetary systems in the universe. Considering this extraordinary environment, our own neighborhood seems a bit dull. The solar system is not chaotic and all the planets are well placed around the sun. Earth may exist simply because the Sun, unlike many other similar stars, has not tended to swallow its planets.

Continue Reading

Space

Do the stars move in the sky and change their position?

Published

on

By

Do the stars move in the sky and change their position?
The stars always seem to be in one fixed point; Don’t they move in the sky?

Do the stars move in the sky and change their position?

The night sky is very dark, But it has its own beauty and those bright points that we call stars adorn the night sky. These stars are eternal stars and are located in fixed constellations, and their location does not change during a person’s life; Even humans who lived in the past saw constellations in the same way we see them and of course used other names to identify them. We now see what ancient humans saw as if the stars were always fixed and did not move, unlike the planets.

Have you ever seen animations made from the movements of galaxies? If you pay close attention, you will see that when these galaxies merge with each other or are affected by each other’s gravity, the stars move like bees to and fro. We all know that the stars also move; But can we never see them move? How fast are these stars moving? Can we ever notice their movement?

Of course, the stars move; But their distance from us is so great that we cannot notice their movement. For thousands of years, astronomers have studied the motion of the stars, calling it astrometry. They observe the stars closely and study how the stars move over many years. Astrometry has a long history and has been done since 190 BC. In 190 BC, Hipparchus, one of the famous astronomers, geographers and mathematicians from ancient Greece, prepared and arranged a long list of 850 bright stars in the sky along with their positions. One of the students of Hipparchus, named Ptolemy, made more observations of the sky and continued in the footsteps of his master. After many observations, he compiled a precious work called al-Majsti (Majsti).

petolmey

Ptolemy called the earth the center of the universe and stated that the stars, the sun, the moon, and other planets revolve around the earth concentrically. Of course, Ptolemy’s view of the world was wrong; But what is important is his precious writings in Kitab al-Majasti. Ptolemy was able to calculate and record the brightness and position of more than 1000 stars in the sky with extraordinary accuracy. A thousand years after Ptolemy, Abdulrahman Sufi, a prominent Iranian mathematician and astronomer, managed to make much more accurate measurements of the sky by means of an astrolabe.

Undoubtedly, one of the most famous astronomers in history is Tycho Brahe. An astronomer from Denmark, he was known by the people for his extraordinary ability to measure the position of the stars. At that time, Tyco Brahe succeeded in designing very precise instruments for tracking stars so that he could track many more stars. He was able to measure the position of the stars with an accuracy of 15 to 35 seconds of arc. In order to make a comparison with the accuracy of Tyco Brahe’s measurement, it is enough to know that a strand of human hair seen at a distance of 10 meters is equal to one second of arc. One interesting thing to know about Brahe is that he had no nose; In fact, Brahe lost his nose in a duel and designed a brass alloy artificial nose to replace it.

In 1807,  Friedrich Bessel, a famous German astronomer, managed to calculate the distance of a nearby star called 61 Cygni or 61 chickens from the Earth for the first time. He used the parallax or parallax method to determine the distance between this star and the Earth. He acted in such a way that he considered the radius of the earth’s orbit around the sun as the base of a triangle and then observed the star. 6 months later, that is, when the earth was on the other side of its orbit with respect to the sun, he again observed the star he wanted. He knew that the stars move in the sky, after measuring this amount of displacement, he measured the distance between the two points of the earth’s orbit where the earth was located during the observation of the star, and then he was able to calculate the distance from the earth to that star. slow

parallax

Two centuries after Friedrich Bessel, astronomers managed to develop this method and accurately calculate the distance of the stars from the Earth and the amount of their displacement; But in order to be able to accurately measure the displacement of the stars and observe them, we need to travel to space. In 1989, the European Space Agency launched a mission called Hipparchus, named after the Greek astronomer. The purpose of the mission was to measure the positions as well as the motions of nearby stars in the Milky Way. During this mission, Hipparchus was able to measure the positions and motions of 118,000 stars with high precision, paving the way for the calculation of another 2 million stars.

Hipparchus was an efficient mission and many astronomers used it; But this mission was not the best because shortly after the end of the mission, a new phenomenon named Gaia arrived.

In December 2013, the European Space Agency launched a new mission called Gaia (named after an ancient legend) to make such calculations for the billion stars in the Milky Way. Although one billion is a very big number, this only accounts for one percent of the stars in the Milky Way. Gaia will soon complete the calculations for 150 million stars and tell us everything that has happened over time. This is a huge achievement and one that Hipparchus would probably be proud of.

gaia

These precise measurements, which took several years, show us how the stars move in the sky. Of course, the movement of the stars cannot be detected with the naked eye, and it may take thousands or tens of thousands of years for a star to slightly change its position in the sky. For example, consider the constellation Ursa Major (the Great Bear); If you could travel back in time or into the future, you would see the stars in this constellation change position, or you might not even be able to recognize this constellation.

When a star moves in one direction in the sky, astronomers call this type of motion ” relative displacement “. The speed of movement of a star in the sky is usually 0.1 seconds of arc per year. This amount is not visible at all; But over the course of 2,000 years, the star can move about half a degree across the sky, or in other words, it can move across the sky as wide as the Moon. The fastest relative displacement is that of Bernard’s Star, which moves across the sky at a speed of 10.25 arcseconds per year, and after 2000 years, it can move as much as 5.5 degrees or 11 times the width of your hand.

star move

When a star moves closer or farther away from us, astronomers say that the star has accelerated radially. They calculate the star’s radial velocity using the Doppler effect . When a star approaches us, the light that reaches us from that star tends towards the blue wavelength, and if that star moves away from us, we see that its light tends towards the red wavelength at the end of the spectrum. This phenomenon is called redshift, which has many uses in astronomy. By taking into account the redshift as well as the relative displacement of a star, we can calculate the path a star has taken in the sky with very high precision. In fact, this is one of the applications of the Doppler effect in astronomy, and another application of the Doppler effect is that it shows us that the universe we live in is expanding.

Read More: Why was Pluto removed from the list of planets in the solar system?

We know that the dwarf star Hipparchus 85605 is moving towards us at a very high speed. This star is currently 16 light years away from us; But by the next 100,000 years, this distance will reach 13 light years (8,200 times the distance of Earth from the Sun). The approach of the star does not directly affect us, But its gravitational effect can take some of the comets that are in the Oort cloud region out of orbit and send them toward the solar system.

star move

The movement of the stars is relatively gentle; But as they move in their orbit around the center of the Milky Way galaxy, they interact gravitationally with each other and may collide. Most stars move slowly, But there are phenomena in the universe that make the stars move at a very high speed.

When a pair of stars get very close to the supermassive black hole cloud at the center of the Milky Way galaxy, one of them gets caught in the black hole’s gravity; But the other star is accelerated and thrown without causing the slightest change in the mass of the other. Once every 100,000 years, a star is ejected from the center of the Milky Way due to being in such a situation.

A similar thing happens when a small star orbits a larger star. Over time, the big star becomes ever bigger and becomes a red giant, and a supernova explosion occurs. It is at this point that the smaller star, like a stone thrown from a rock hook, will no longer be affected by gravity and will be thrown towards the boundless space at an extraordinary speed. Astronomers have found that these stars are moving at a speed of 1.1 million kilometers per hour towards the center of the Milky Way galaxy.

Star

All the movements we have talked about had a natural origin; But imagine that in the future, human civilization or other civilizations will be advanced enough to move a star in different directions at will. In 1987, a Russian astrophysicist named Leonid Shkadov presented a very advanced method by which scientists could move a star at a slow speed. Of course, this was a very imaginative hypothesis; But it is not impossible to do. The method presented by Shkadov was such that a very large mirror was placed on one side of the star and the star itself could act as an accelerator. Photons hitting the mirror from the star were reflected, creating a momentum similar to a solar sail.

The mirror that is made must be big enough to have a gravitational interaction with the star and overcome it, But the light can create enough pressure to prevent the star from moving toward the mirror. This can create a very weak but steady push on the other side of the star, moving it in any direction our civilization wants. It may take billions of years for the star to settle in the desired position, But it is possible to do this in the future.

Star

Those who are able to do such a thing will be a type 3 civilization. A Type 3 civilization could control vast swaths of the Milky Way galaxy, harness and control the energy of billions of stars, and continue to expand its empire. It is possible that this civilization could gather all the stars together in a sphere or place them in a flat disk to minimize communication time. Astronomers are now looking for galaxies that are under the control of a Type 3 civilization. Such galaxies can be seen at visible wavelengths; But unfortunately, we have not managed to observe one of them, which of course is normal; Because the galaxies that are in this world are very far from us and we cannot observe some of them.

Our lifespan as humans is limited and that is why we think that the stars are fixed in the sky and do not move; But if you can speed up time, you will see that everything in the sky is moving and the stars are moving back and forth like airplanes. Unfortunately, limited life does not allow us to enjoy this beautiful view.

Continue Reading

Popular