The largest planet in the solar system
Jupiter. Its equatorial diameter is 143884 km, which is 11.209 times the diameter of the Earth and is 0.103 times the diameter of the Sun. Jupiter's shape is not completely spherical because the planet is made of gas and liquid and rotates rapidly. The polar diameter of Jupiter is 133,708 km. The mass of Jupiter is 318 times the mass of the Earth and 2.5 times the mass of all other planets combined. Jupiter is only 1047 times less massive than the Sun.
The smallest planet in the solar system
Pluto. Its diameter is only 2400 km. The rotation period is 6.39 days. The mass is 500 times less than the earth's. Has a satellite, Charon, discovered by J. Christie and R. Harrington in 1978.
The brightest planet in the solar system
Venus. Its maximum magnitude is -4.4. Venus comes closest to Earth and, in addition, reflects sunlight most effectively, since the planet's surface is covered with clouds. The top layers of Venus's clouds reflect 76% of what falls on them sunlight. When Venus appears brightest, it is in its crescent phase. Venus's orbit is closer to the Sun than the Earth's, so Venus's disk is only fully illuminated when it is on the opposite side of the Sun. At this time, the distance to Venus is greatest, and its apparent diameter is smallest.
The largest satellite in the solar system
Ganymede is a satellite of Jupiter with a diameter of 5262 km. Saturn's largest moon, Titan, is the second largest (its diameter is 5,150 km), and at one time it was even thought that Titan was larger than Ganymede. In third place is Jupiter's satellite, Callisto, adjacent to Ganymede. Both Ganymede and Callisto are larger than the planet Mercury (which has a diameter of 4878 km). Ganymede owes its status as the "largest moon" to the thick mantle of ice that covers its rocky interior. The solid cores of Ganymede and Callisto are likely similar in size to Jupiter's two small inner Galilean moons, Io (3,630 km) and Europa (3,138 km).
The smallest satellite in the solar system
Deimos is a satellite of Mars. The smallest satellite, the dimensions of which are precisely known, Deimos, roughly speaking, has the shape of an ellipsoid with dimensions of 15x12x11 km. Its possible rival is Jupiter's moon Leda, which is estimated to be about 10 km in diameter.
The largest asteroid in the solar system
Ceres. Its dimensions are 970x930 km. In addition, this asteroid was the very first to be discovered. It was discovered by Italian astronomer Giuseppe Piazzi on January 1, 1801. The asteroid got its name because Ceres, the Roman goddess, was associated with Sicily, where Piazzi was born. The next largest asteroid after Ceres is Pallas, discovered in 1802. Its diameter is 523 km. Ceres orbits the Sun in the main asteroid belt, located at a distance of 2.7 AU from it. e. It contains a third of the total mass of all more than seven thousand known asteroids. Although Ceres is the largest asteroid, it is not the brightest because its dark surface reflects only 9% of sunlight. Its brightness reaches 7.3 magnitude.
The brightest asteroid in the solar system
Vesta. Its brightness reaches magnitude 5.5. In very dark skies, Vesta can even be seen with the naked eye (it is the only asteroid that can be seen with the naked eye at all). The next brightest asteroid is Ceres, but its brightness never exceeds magnitude 7.3. Although Vesta is more than half the size of Ceres, it is much more reflective. Vesta reflects about 25% of the sunlight that hits it, while Ceres reflects only 5%.
The largest crater on the Moon
Hertzsprung. Its diameter is 591 km and it is located on the far side of the Moon. This crater is a multi-ringed impactor. Similar impact structures on the visible side of the Moon were later filled with lava, which hardened into dark, hard rock. These features are now commonly referred to as maria rather than craters. However, no such volcanic eruptions occurred on the far side of the Moon.
The most famous comet
Sightings of Halley's Comet have been traced back to 239 BC. There is no historical record for any other comet that can compare with Halley's Comet. Halley's Comet is unique: it has been observed 30 times over more than two thousand years. This is because Halley's comet is much larger and more active than other periodic comets. The comet is named for Edmund Halley, who in 1705 realized the connection between several previous appearances of the comet and predicted its return in 1758-59. In 1986, the Giotto spacecraft was able to image the nucleus of Halley's Comet from a distance of only 10 thousand kilometers. It turned out that the core is 15 km long and 8 km wide.
The brightest comets
The brightest comets of the 20th century include the so-called “Great Daylight Comet” (1910), Halley’s Comet (when it appeared in the same 1910), comets Schellerup-Maristany (1927), Bennett (1970) , Vesta (1976), Heil-Bopp (1997). The brightest comets of the 19th century are probably the "Great Comets" of 1811, 1861, and 1882. Previously, very bright comets were recorded in 1743, 1577, 1471 and 1402. The closest (and brightest) appearance of Halley's Comet was noted in 837.
Closest comet
Lexel. The closest distance to Earth was reached on July 1, 1770 and was 0.015 astronomical units (i.e. 2.244 million kilometers or about 3 times the diameter of the Moon's orbit). When the comet was closest, the apparent size of its coma was almost five times the diameter of the full Moon. The comet was discovered by Charles Messier on June 14, 1770, but got its name from Anders Johann (Andrei Ivanovich) Lexel, who determined the comet's orbit and published the results of his calculations in 1772 and 1779. He found that in 1767 the comet came close to Jupiter and, under its gravitational influence, moved into an orbit that passed close to the Earth.
Longest total solar eclipse
Theoretically, the total eclipse phase can take the entire time of a total solar eclipse - 7 minutes 31 seconds. In practice, however, such long eclipses have not been recorded. The longest total eclipse in recent history was that of June 20, 1955. It was observed from the Philippine Islands and lasted 7 minutes 8 seconds for totality. The longest eclipse in the future will take place on July 5, 2168, when the total phase will last 7 minutes 28 seconds.
Nearest star
Proxima Centauri. It is located 4.25 light years from the Sun. It is believed that, together with the double star Alpha Centauri A and B, it is part of a free triple system. The double star Alpha Centauri is a little further away from us, at a distance of 4.4 light years. The Sun lies in one of the spiral arms of the Galaxy (the Orion Arm), at a distance of about 28,000 light years from its center. At the location of the Sun, the stars are usually several light years apart from each other.
Brightest star
Sirius. Its magnitude is -1.44. Sirius got its name from Ancient Greece, and it means “scorching.” Sirius is sometimes called the Dog Star after the constellation Canis Major to which he belongs. At just 8.7 light-years away, Sirius is one of the closest stars to the Sun. The next brightest star after Sirius is Canopus in the constellation Carina, which has a magnitude of -0.72. In fact, Sirius is a system of two stars revolving around each other. Almost all of the light comes to us from the main star, which is called Sirius A and is a white normal star about 2.3 times more massive than the Sun. The fainter companion, Sirius B, discovered by visual observation in 1862, is a white dwarf. The light from Sirius B is only one ten-thousandth of the light from Sirius A. The Sirius binary system completes one revolution every 50 years.
The most powerful star in terms of radiation
Star in a Pistol. In 1997, astronomers working with the Hubble Space Telescope discovered this star. They named it the "Star in a Pistol" after the shape of the nebula surrounding it. Although the radiation from this star is 10 million times more powerful than that of the Sun, it is not visible to the naked eye because it is located near the center of the Milky Way at a distance of 25,000 light years from Earth and is hidden by large clouds of dust. Before the discovery of the Pistol Star, the most serious contender was Eta Carinae, which was 4 million times more luminous than the Sun.
Biggest star
Mu Cepheus. Currently, the largest star is considered to be mu Cephei, with a diameter of more than 1.6 billion kilometers. Placed at the center of the solar system, this star would absorb all the planets up to and including Saturn.
The fastest star
Barnard's Star. Opened in 1916 and is still the star with the largest proper motion. The star's unofficial name (Barnard's Star) is now generally accepted. Its proper motion per year is 10.31". Barnard's Star is one of the closest stars to the Sun (next after Proxima Centauri and the binary system Alpha Centauri A and B). In addition, Barnard's Star moves in the direction of the Sun, approaching it by 0.036 light years per century. In 9,000 years, it will become the closest star, taking the place of Proxima Centauri.
Brightest supernova
A star from the constellation Lupus observed in 1006 AD. Based on many surviving observational records, it can be established that the apparent magnitude of the supernova was about -10, which is comparable to the Moon. The position of this supernova was identified by a known supernova remnant (number PKS 1459-41), which emits radio waves and X-rays and is observed as faint filaments in the optical spectrum. The distance to the supernova is estimated at 3260 light years. At the moment of maximum brightness, all supernovae reach approximately the same absolute magnitude, but their apparent brightness depends on both the distance and the amount of dust in the path of the light beam. The next brightest (after the supernova of 1006) is the explosion of 1054, which created the Crab Nebula in Taurus. This supernova reached an apparent magnitude of -5.
Largest known globular cluster
Omega Centauri. It contains millions of stars concentrated in a volume about 620 light years in diameter. The shape of the cluster is not entirely spherical: it looks slightly flattened. In addition, Omega Centauri is also the brightest globular cluster in the sky with a total magnitude of 3.6. It is 16,500 light years away from us. The name of the cluster has the same form as the names of individual stars usually have. It was assigned to the cluster in ancient times, when it was impossible to recognize the true nature of the object when observing with the naked eye. Omega Centauri is one of the oldest clusters.
Nearest galaxy
The dwarf galaxy in the constellation Sagittarius is the closest galaxy to the Milky Way Galaxy. This small galaxy is so close that the Milky Way seems to be swallowing it up. The galaxy lies 80,000 light-years from the Sun and 52,000 light-years from the center of the Milky Way. The next closest galaxy to us is the Large Magellanic Cloud, located 170 thousand light years away.
Farthest object visible to the naked eye
The most distant object that can be seen with the naked eye is the Andromeda Galaxy (M31). It lies about 2 million light-years away and is about the brightness of a 4th magnitude star. It is a very large spiral galaxy, the largest member of the Local Group, to which our own Galaxy belongs. Besides it, only two other galaxies can be observed with the naked eye - the Large and Small Magellanic Clouds. They are brighter than the Andromeda Nebula, but much smaller and less distant (at 170,000 and 210,000 light years, respectively). However, it should be noted that sharp-eyed people on a dark night can see the M31 galaxy in the constellation Ursa Major, the distance to which is 1.6 Megaparsecs.
Largest constellation
Hydra. The area of the sky included in the constellation Hydra is 1302.84 square degrees, which is 3.16% of the entire sky. The next largest constellation is Virgo, occupying 1294.43 square degrees. Most of the Hydra constellation lies south of the celestial equator, and its total length is more than 100°. Despite its size, Hydra does not stand out particularly in the sky. It mainly consists of fairly faint stars and is not easy to find. The brightest star is Alphard, a second magnitude orange giant located 130 light years away.
Smallest constellation
Southern Cross. This constellation occupies an area of the sky of only 68.45 square degrees, which is equivalent to 0.166% of the entire sky area. Despite its small size, the Southern Cross is a very prominent constellation that has become a symbol of the southern hemisphere. It contains twenty stars brighter than magnitude 5.5. Three of the four stars that form his cross are 1st magnitude stars. The Southern Cross constellation contains an open star cluster (Kappa Crucis, or "Jewel Box" cluster), considered by many observers to be one of the most beautiful in the sky. The next smallest constellation (more precisely, occupying 87th place among all constellations) is the Lesser Horse. It covers 71.64 square degrees, i.e. 0.174% of the sky area.
The largest optical telescopes
Two Keck Telescopes located side by side on the summit of Mauna Kea, Hawaii. Each of them has a reflector with a diameter of 10 meters, made up of 36 hexagonal elements. They were meant to work together from the very beginning. Since 1976, the largest optical telescope with a solid mirror has been the Russian Large Azimuth Telescope. Its mirror has a diameter of 6.0 m. For 28 years (1948 - 1976), the largest optical telescope in the world was the Hale Telescope on Mount Palomar in California. Its mirror has a diameter of 5 m. The Very Large Telescope, located in Cerro Paranal in Chile, is a structure of four mirrors with a diameter of 8.2 m, which are connected together to form a single telescope with a 16.4-meter reflector.
The world's largest radio telescope
Arecibo Observatory radio telescope in Puerto Rico. It is built into a natural depression on the earth's surface and has a diameter of 305 m. The world's largest fully controlled radio antenna is the Green Bank Telescope in West Virginia in the USA. Its antenna diameter is 100 m. The largest radio telescope array located in one place is the Very Large Array (VLA), which consists of 27 antennas and is located near Socorro in New Mexico, USA. In Russia, the largest radio telescope is "RATAN-600" with a diameter of 600 meters of antenna-mirrors installed around the circumference.
Nearest galaxies
Astronomical object number M31, better known as the Andromeda nebula, is located closest to us than all other giant galaxies. In the Northern Hemisphere sky, this galaxy appears the brightest from Earth. The distance to it is only 670 kpc, which in our usual measurements is a little less than 2.2 million light years. The mass of this galaxy is 3 x 10 times the mass of the Sun. Despite its enormous size and mass, the Andromeda nebula is similar to the Milky Way. Both galaxies are giant spiral galaxies. The closest to us are the small satellites of our Galaxy - the Large and Small Magellanic clouds of irregular configuration. The distance to these objects is 170 thousand and 205 thousand light years, respectively, which is negligible compared to the distances used in astronomical calculations. Magellanic clouds are visible to the naked eye in the sky in the Southern Hemisphere.
The most distant galaxies
Among the astrophysicists who devoted their creative activity The study of distant galaxies is highlighted by X. Spinrad, an employee of the University of California at Berkeley. He is responsible for the discoveries of more than one ultra-distant galaxy. Initially, Spinrad in 1975 discovered the record-breaking galaxy in the northern direction of the Pleiades star cluster, located at a distance of 8 billion light years from us. This galaxy is listed in the star catalog as number 3S 123. It has the strongest level of radio emission, exceeding the strength of such radiation from other giant galaxies by about 6 times.
In another series of observations carried out in 1984 using the 4-meter reflector of the KittPeak National Observatory in the US state of Arizona, Spinrad discovered a number of radio galaxies, among which were the most distant ones known to science.
Optical radiation, for example, from the radio galaxy 3S 256 reaches the Solar System over a long period of 10 billion years. In addition, the distance continues to increase, as it moves away from us at a speed of 200 thousand km/s. Unlike other nearby radio galaxies with pronounced elliptical shapes, this one has an irregularly elongated configuration. A more or less clear image of another record-breaking galaxy in terms of distance was recently obtained by American astronomers K. Chambers and J. Mealy at the Leiden Observatory. The distance to it is 12 billion light years.
It is no coincidence that astrophysicists have their own close attention pay attention to ultra-distant astronomical objects. By processing information collected over more than one billion light years, it is possible to form a generalized idea of the distant past of star formations, especially at the initial stages of their formation and origin, during the period corresponding to the beginning of the process of expansion of the Universe. The discovery of more and more ultra-distant galaxies does not occur by chance. They are most often the fruit of many years of focused work by more than one group of astronomers. This is evidenced by the recent discovery of another of the most distant galaxies with an apparent magnitude of 20.19. This became possible thanks to the implementation of a pre-planned program of searching for ultra-distant galaxies with weak radiation in the vicinity of other already known celestial bodies, including quasars (quasi-stellar sources of radio emission), emitting many times more energy than the most powerful galaxies. The record-breaking galaxy was discovered near the quasar PKS 1614+051 with a redshift value of Z = 3.209. Light radiation from it was emitted when the Universe was. three times younger than now.
The most distant star in our Galaxy
A group of astronomers from the University of Washington has discovered the most distant star in our Galaxy - an 18-magnitude red giant. This star is located in the direction of the constellation Libra and is removed from the Earth at a distance that light can travel in 400 thousand years. It is clear that this star is located at the boundary line, in the so-called galactic halo zone. After all, the distance to this star is approximately 4 times the diameter of the imaginary expanses of our Galaxy. (The diameter of the Milky Way is estimated at about 100 thousand light years.) It is surprising that the most distant, fairly bright star was discovered only in our time, although it had been observed before. For unknown reasons, astronomers did not pay much attention to the faintly luminous spot on the starry sky and visible on the photographic plate. What happens? People see the star for a quarter of a century and... do not notice it. More recently, American astronomers from the Lowell Observatory discovered another of the most distant stars in the peripheral reaches of our Galaxy. This star, already dimmed from “old age,” can be searched in the sky in the location of the constellation Virgo, at a distance of approximately 160 thousand light years. Such discoveries in the dark (literally and figuratively) areas of the Milky Way allow us to make important adjustments in determining the true values of the mass and size of our star system in the direction of their significant increase. And this can seriously affect the cosmological picture of the universe accepted in the scientific community.
Most open star cluster
Of all the star clusters, the most scattered throughout outer space is a collection of stars called the Coma of Berenices. The stars here are scattered at such vast distances from each other that they look like cranes flying in a chain. Therefore, the constellation, which is a decoration of the starry sky, is also called the “Wedge of Flying Cranes.”
Superdense galaxy clusters
It is known that the Milky Way galaxy, together with the Solar system, is located in a spiral galaxy, which in turn is part of a system formed by a cluster of galaxies. There are many such clusters in the Universe. I wonder which galaxy cluster is the densest and largest? According to scientific publications, scientists have long suspected the existence of giant supersystems of galaxies. Recently, the problem of superclusters of galaxies in a limited space of the Universe has attracted increasing attention of researchers. And primarily because studying this issue can provide additional important information about the birth and nature of galaxies and radically change existing ideas about the origins of the Universe.
Over the past few years, giant star clusters have been discovered in the sky. The densest cluster of galaxies in a relatively small area of world space was recorded by American astronomer L. Cowie from the University of Hawaii. This supercluster of galaxies is located at a distance of 5 billion light years from us. It emits as much energy as several trillion celestial bodies like the Sun combined could produce.
At the beginning of 1990, American astronomers M. Keller and J. Haykr identified a super-dense cluster of galaxies, which was given the name “Great Wall”, by analogy with the Great Wall of China. The length of this stellar wall is approximately 500 million light years, and its width and thickness are 200 and 50 million light years, respectively. The formation of such a star cluster does not fit into the generally accepted big bang theory of the origin of the Universe, from which the relative uniformity of the distribution of matter in space follows. This discovery posed a rather difficult task for scientists.
It should be noted that the closest galaxy clusters to us are located in the constellations Pegasus and Pisces at a distance of only 212 million light years. But why are galaxies located at a greater distance from us in denser layers relative to each other than in the parts of the Universe closest to us, as expected? Astrophysicists are still scratching their heads over this difficult question.
Nearest star cluster
The closest open star cluster to the Solar System is the famous Hyades in the constellation Taurus. It looks good against the background of the winter starry sky and is recognized as one of the most wonderful creations of nature. Of all the star clusters in the northern starry sky, the constellation Orion is best distinguished. This is where some of the brightest stars are located, including the star Rigel, located 820 light-years away.
Supermassive black hole
Black holes often involve nearby cosmic bodies in rotational motion around them. The unusually rapid rotation of astronomical objects around the center of the Galaxy, which is 300 million light-years away from us, was discovered quite recently. According to experts, such an ultra-high speed of rotation of bodies is due to the presence in this part of world space of a supermassive black hole, the mass of which is equal to the mass of all the bodies of the Galaxy taken together (approximately 1.4x1011 masses of the Sun). But the fact is that such mass is concentrated in a part of space 10 thousand times smaller than our Milky Way star system. This astronomical discovery so amazed American astrophysicists that it was decided to immediately begin a comprehensive study of the supermassive black hole, the radiation of which is closed in on itself by powerful gravity. For this purpose, it is planned to use the capabilities of an automatic gamma observatory launched into low-Earth orbit. Perhaps such determination of scientists in studying the mysteries of astronomical science will finally make it possible to clarify the nature of mysterious black holes.
Largest astronomical object
The largest astronomical object in the Universe is noted in star catalogs under the number ZS 345, registered in the early 80s. This quasar is located 5 billion light years from Earth. German astronomers, using a 100-meter radio telescope and a fundamentally new type of radio frequency receiver, measured such a distant object in the Universe. The results were so unexpected that scientists did not believe them at first. It's no joke, the quasar was 78 million light years across. Despite such a great distance from us, when observed, the object appears twice as large as the lunar disk.
Largest galaxy
Australian astronomer D. Malin discovered a new galaxy in 1985 while studying a section of the starry sky in the direction of the constellation Virgo. But D. Malin considered his mission complete. Only after the rediscovery of this galaxy by American astrophysicists in 1987 did it turn out that it was a spiral galaxy, the largest and at the same time the darkest of all then known to science.
Located at a distance of 715 million light years from us, it has a cross-sectional length of 770 thousand light years, almost 8 times the diameter of the Milky Way. The luminosity of this galaxy is 100 times less than the luminosity of ordinary spiral galaxies.
However, as the subsequent development of astronomy showed, even larger galaxies were listed in star catalogs. From the vast class of weakly luminous formations in the Metagalaxy, called Markarian galaxies, galaxy number 348, discovered a quarter of a century ago, was isolated. But then the size of the galaxy was clearly underestimated. Later observations by American astronomers using a radio telescope located in Socorro, New Mexico, made it possible to establish its true size. The record holder has a diameter of 1.3 million light years, which is already 13 times the diameter of the Milky Way. It is 300 million light years away from us.
Biggest star
At one time, Abell compiled a Catalog of Galactic Clusters, consisting of 2712 units. According to it, in galaxy cluster number 2029, the largest galaxy in the Universe was discovered right in the center. Its diameter is 60 times larger than the Milky Way and is about 6 million light years, and its radiation is more than a quarter of the total radiation of the galaxy cluster. Astronomers from the United States recently discovered a very large star. Research is still ongoing, but it is already known that a new record holder has appeared in the Universe. According to preliminary results, the size of this star is 3500 times greater than the size of our star. And it emits 40 times more energy than the hottest stars in the Universe.
The brightest astronomical object
In 1984, the German astronomer G. Kuhr and his colleagues discovered such a dazzling quasar (quasi-stellar source of radio emission) in the starry sky that even at a great distance from our planet, estimated at many hundreds of light years, it would not be inferior to the Sun in terms of the intensity of light emission sent to the Earth, although it is distant from us in outer space, which light can travel in 10 billion years. In its brightness, this quasar is not inferior to the brightness of ordinary 10 thousand galaxies combined. In the star catalogue, it received the number S 50014+81 and is considered the brightest astronomical object in the boundless expanses of the Universe. Despite its relatively small size, reaching a diameter of several light years, a quasar emits much more energy than an entire giant galaxy. If the radio emission of an ordinary galaxy is 10 J/s, and the optical emission is 10, then for a quasar these values are 10 and 10 J/s, respectively. Note that the nature of the quasar has not yet been clarified, although there are different hypotheses: quasars are either the remnants of dead galaxies, or, on the contrary, objects of the initial stage of the evolution of galaxies, or something else completely new.
The brightest stars
According to information that has reached us, the ancient Greek astronomer Hipparchus first began to distinguish stars by their brightness back in the 2nd century BC. e. To estimate the luminosity of different stars, he divided them into 6 degrees, introducing the concept of stellar magnitude into use. At the very beginning of the 17th century, the German astronomer I. Bayer proposed to designate the degree of brightness of stars in different constellations with letters Greek alphabet. The brightest stars are called “alpha” of such and such a constellation, the next brightest stars are called “beta”, etc.
The brightest stars in our visible sky are Deneb from the constellation Cygnus and Rigel from the constellation Orion. The luminosity of each of them exceeds the luminosity of the Sun by 72.5 thousand and 55 thousand times, respectively, and the distance from us is 1600 and 820 light years.
In the constellation Orion there is another brightest star - the third most luminous star Betelgeuse. In terms of light emission power, it is 22 thousand times brighter than sunlight. The most bright stars, although their brightness changes periodically, are collected precisely in the constellation Orion.
The star Sirius from the constellation Canis Major, which is considered the brightest among the stars closest to us, is only 23.5 times brighter than our star; the distance to it is 8.6 light years. There are even brighter stars in the same constellation. Thus, the star of Adara shines as bright as 8,700 suns combined at a distance of 650 light years. And the North Star, which for some reason was incorrectly considered the brightest visible star and which is located at the tip of Ursa Minor at a distance of 780 light years from us, shines only 6000 times brighter than the Sun.
The zodiac constellation Taurus is notable for the fact that it contains unusual star, characterized by supergiant density and relatively small spherical size. As astrophysicists have found out, it mainly consists of fast neutrons scattering into different sides. This star was for some time considered the brightest in the Universe.
In general, blue stars have the greatest luminosity. The brightest star known is UW SMa, which shines 860 thousand times brighter than the Sun. Over time, the brightness of stars can change. Therefore, the star that holds the record for brightness may also change. For example, reading an ancient chronicle dated July 4, 1054, you can find out that the brightest star shone in the constellation Taurus, which was visible to the naked eye even during the day. But over time, it began to fade and within a year it disappeared altogether. Soon, in the place where the star shone brightly, a nebula very similar to a crab began to be discerned. Hence the name - the Crab Nebula, which was born as a result of a supernova explosion. Modern astronomers have discovered a powerful source of radio emission, the so-called pulsar, in the center of this nebula. It is the remnant of that bright supernova described in the ancient chronicle.
the brightest star in the Universe - blue star UW SMa;
the brightest star in the visible sky is Deneb;
the brightest nearby star is Sirius;
the brightest star in the Northern Hemisphere is Arcturus;
the brightest star in our northern sky is Vega;
the brightest planet in the solar system is Venus;
The brightest minor planet is Vesta.
The dimmest star
Of the many faint fading stars scattered throughout space, the faintest is located 68 light years from our planet. If this star is 20 times smaller in size than the Sun, then in luminosity it is already 20 thousand times smaller. The previous record holder emitted 30% more light.
First evidence of a supernova explosion
Astronomers call supernovae stellar objects that suddenly burst into flames and reach their maximum luminosity in a relatively short period of time. As we have been able to establish, the oldest evidence of a supernova explosion from all surviving astronomical observations dates back to the 14th century BC. e. Then ancient Chinese thinkers registered the birth of a supernova and indicated its location and time of outbreak on the shell of a large turtle. Modern researchers have been able to use the armored manuscript to determine the place in the Universe where a powerful source of gamma radiation is currently located. There is hope that such ancient evidence will help to fully understand the problems associated with supernovae and trace the evolutionary path of special stars in the Universe. Such evidence plays an important role in the modern interpretation of the nature of the birth and death of stars.
Shortest-lived star
The discovery of a new type of X-ray star in the area of the Southern Cross and Centaurus constellations in the 70s by a group of Australian astronomers led by K. McCarren caused a lot of noise. The fact is that scientists witnessed the birth and death of a star, the lifespan of which was an unprecedentedly short time - about 2 years. This has never happened before in the entire history of astronomy. The suddenly flared star lost its shine in a time that was negligibly short for stellar processes.
The most ancient stars
Astrophysicists from the Netherlands have developed a new, more advanced method for determining the age of the oldest stars in our Galaxy. It turns out that after the so-called big bang and the formation of the first stars in the Universe, only 12 billion light years passed, i.e. much less time than previously thought. Time will tell how correct these scientists are in their judgments.
Youngest star
According to scientists from the UK, Germany and the USA, conducting joint research, the youngest stars are located in the nebula NGC 1333. This nebula is located at a distance of 1100 light years from us. It has attracted increased attention from astrophysicists since 1983 as the most convenient object of observation, the study of which will reveal the mechanism of star birth. Quite reliable data received from the infrared satellite "IRAS" confirmed astronomers' guesses about the ongoing violent processes characteristic of the early stages of star formation. At least 7 of the brightest star births were recorded somewhat south of this nebula. Among them, the youngest was identified, called “IRAS-4”. His age turned out to be quite “infantile”: only a few thousand years. It will take many more hundreds of thousands of years for the star to reach the stage of its maturation, when the conditions for raging nuclear chain reactions will be created in its core.
The smallest star
In 1986, through the efforts of mainly American astronomers from the KittPeak Observatory, a previously unknown star was discovered in our Galaxy, designated LHS 2924, whose mass is 20 times less than that of the Sun, and whose luminosity is six orders of magnitude less. This star turned out to be the smallest in our Galaxy. Its light emission occurs as a result of the resulting thermonuclear reaction of converting hydrogen into helium.
The fastest star
At the beginning of 1993, a message was received from Cornell University that an unusually fast moving stellar object had been discovered in the depths of the Universe, which received the number PSR 2224+65 in the star catalogue. During a correspondence meeting with the new star, the discoverers were immediately confronted with two features. Firstly, it turned out to be not round in shape, but guitar-shaped. Secondly, this star moved through space at a speed of 3.6 million km/h, which far exceeds all other known stellar speeds. The speed of the newly discovered star is 100 times higher than the speed of our star. This star is at such a distance from us that if it were moving towards us, it could cover it in 100 million years.
The fastest rotations of astronomical objects
In nature, pulsars, pulsating sources of radio emission, rotate the fastest. The speed of their rotation is so enormous that the light they emit is focused into a thin conical beam, which an earthly observer can register at regular intervals. The progress of atomic clocks can be verified with the greatest accuracy using pulsar radio emissions. The fastest astronomical object was discovered by a group of American astronomers at the end of 1982 using the large radio telescope at Arecibo on the island of Puerto Rico. This is a super-fast-rotating pulsar with the assigned designation PSR 1937+215, located in the constellation Vulpecula at a distance of 16 thousand light years. In general, pulsars have been known to mankind for only a quarter of a century. They were first discovered in 1967 by a group of English astronomers led by Nobel laureate E. Hewish as sources of electromagnetic radiation pulsating with high precision. The nature of pulsars is not fully understood, but many experts believe that they are neutron stars rapidly rotating around their own axis, exciting strong magnetic fields. But the newly discovered record-breaking pulsar rotates at a frequency of 642 rps. The previous record belonged to a pulsar from the center of the Crab Nebula, which produces strictly periodic pulses of radio emission with a period of 0.033 rps. While other pulsars usually emit waves in the radio range from meter to centimeter, this pulsar also emits in the X-ray and gamma-ray ranges. And it was in this pulsar that slowing pulsations were first discovered. Recently, through the joint efforts of researchers from the European Space Agency and the famous Los Alamos Scientific Laboratory, a new double star system was discovered while studying the X-ray emission of stars. Scientists were most interested in the unusually rapid rotation of its components around its center. The distance between the celestial bodies included in the star pair was also record close. In this case, the resulting powerful gravitational field includes a nearby white dwarf in its sphere of action, thereby causing it to rotate at a colossal speed of 1200 km/s. The intensity of X-ray radiation from this pair of stars is approximately 10 thousand times higher than the radiation from the Sun.
Highest speeds
Until recently, it was believed that the limiting speed of propagation of any physical interactions was the speed of light. According to experts, there should not be a speed of movement higher than 299,792,458 m/s, with which light propagates in a vacuum. This follows from Einstein's theory of relativity. True, recently many prestigious scientific centers have increasingly begun to declare the existence of superluminal movements in global space. For the first time, superluminal data were obtained by American astrophysicists R. Walker and J. M. Benson in 1987. While observing the radio source ZS 120, located at a considerable distance from the galactic core, these researchers recorded the speed of movement individual elements radio structures exceeding the speed of light. A thorough analysis of the combined radio map of the ZS 120 source gave a linear velocity value of 3.7 ± 1.2 times the speed of light. Scientists have not yet operated with large values of movement speeds.
The strongest gravitational lens in the Universe
The phenomenon of a gravitational lens was predicted by Einstein. It creates the illusion of a double image of an astronomical object of radiation through a powerful gravitational field located in the path of the source, bending the rays of light. For the first time, Einstein's hypothesis received real confirmation in 1979. Since then, a dozen gravitational lenses have been discovered. The strongest of them was discovered in March 1986 by American astrophysicists from the Kittpik Observatory, led by E. Turner. When observing one quasar, distant from the Earth at a distance of 5 billion light years, its bifurcation was recorded, separated by 157 arc seconds. This is a fantastic amount. Suffice it to say that other gravitational lenses lead to a split image lasting no more than seven arc seconds. Apparently, the reason for such a colossal split in the image is a supermassive black hole, which is 1000 times heavier than our Galaxy, as a result of which a powerful gravitational field is created in this part of the space of the Universe.
The most powerful magnet in the Universe
The strongest magnetic field in the Universe is formed in the vicinity of a fifteenth-magnitude star with the astronomical designation PG 1031+234. It is a white dwarf about the same size as Earth, but located 100 light years away from the star. American astrophysicists from the University of Arizona in the mid-80s determined the magnitude of magnetic induction in this region of space and... could not believe it. The instrument readings were at the level of 70 thousand teslas, or in Gaussian units - 700 million. Such a strong magnetic field has never been observed in the Universe.
Unique gas and dust clouds in space
At the end of the 70s, information appeared in the press about the discovery of a giant gas and dust cloud in interstellar space. According to scientists, the mass of this cloud is a trillion times greater than the mass of the Sun (1.9889x1030 kg). This is the largest gas and dust cloud in the Universe. And the brightest gas and dust cloud in interstellar space is the Orion Nebula. The mass of the superhot gas cloud exceeds the mass of the Sun by 300 times, and it is located at a distance of approximately 1.5 thousand light years from us.
The largest hydrogen cloud in the Universe
An impressively large cloud of neutral hydrogen was discovered in the Universe quite by accident while solving other astronomical problems at Arecibo by American astronomers from Cornell University. The diameter of this cloud is 10 times larger than our Galaxy, and the hydrogen mass in the cloud is almost a billion times larger than the mass of our star. The cloud is located towards the constellation Leo at a distance of 65 million light years from Earth and rotates around the center of mass at a speed of 80 km/s. As scientists suggest, the birth of a new galaxy is possible from this giant hydrogen cloud. This casts doubt on the widespread big bang theory of the simultaneous birth of all galaxies after a colossal explosion in the Universe.
The most abundant substance in interstellar space
Molecules of more than 60 chemical substances have been identified in the lifeless interstellar medium. Most of all, hydrogen is found in interstellar space. In terms of prevalence, hydrogen is far ahead of the total content of all other chemical elements. If we take the hydrogen content as a unit, then the relative content of helium will be 0.09, oxygen - 0.0007, carbon - 0.0003, nitrogen - 0.00009.
The most dense clusters of astronomical objects
Black holes are the densest clusters of astronomical objects. The densest clusters of cosmic objects are the so-called black holes, predicted by the theory of relativity. In outer space, the emergence of black holes occurs as a result of the colossal gravitational compression of supermassive astronomical objects. The compression is so strong that the resulting gravitational field does not even let light radiation out of its zone of influence. According to astrophysicists, the cosmic density in black holes reaches 5x10 Mg/m. This is such a huge quantity that it is difficult to imagine or compare with measured quantities in nature. For comparison: the density of a neutron star and the density of an atomic nucleus is 10.4 Mg/m, and the Sun is only 1.4 Mg/m. The average density in an ordinary galaxy is 2x1 Mg/m, and in the entire Universe it is presumably 10 Mg/m.
Which star rotates the fastest? Apart from neutron stars and other products of stellar evolution, the answer must be sought among massive young stars. Just recently, astronomers discovered a record-breaking star that rotates faster than any other normal star. Astronomers made their discovery using the European Southern Observatory's Very Large Telescope, according to an ESO press release.
The fastest-spinning star is in the Milky Way's satellite galaxy, the Large Magellanic Cloud, 160,000 light-years from Earth. Astronomers identified it during a survey of the brightest and most massive stars in , the cradle of thousands of stars in the Large Magellanic Cloud. Among the many stars shining in this nebula, VFTS 102 has one very unique characteristic: it rotates at over 2 million kilometers per hour! This is more than 300 times the rotation speed of the Sun and very close to the critical speed at which the star would be torn apart by centrifugal force. The star VFTS 102 is by far the fastest rotating star.
A section of the Tarantula Nebula in the Large Magellanic Cloud. The arrow shows the star VFTS 102, which is the fastest rotating star known. The image was created from a combination of optical and infrared images taken by the 2.2-meter MPG/ESO telescope at La Silla Observatory and the 4.1-meter VISTA infrared telescope at Paranal Observatory. Photo: ESO/M.-R. Cioni/VISTA Magellanic Cloud survey/Cambridge Astronomical Survey Unit
Let's get to know her better. It is a true giant star, 25 times more massive than the Sun and about 100,000 times brighter. By cosmic standards, the life of such stars is short, like that of a one-day butterfly. Having exhausted their nuclear fuel, they explode into supernovae. In these brief moments, their luminosity often exceeds the luminosity of an entire galaxy.
“The incredibly high rotation rate and unusual motion among surrounding stars led us to wonder if something unusual had happened to this star in the early stages of its existence. Suspicions gripped us."Astronomers have discovered that the star VFTS 102 is moving through space at a speed significantly different from the speed of its neighboring stars. “The incredibly high rotation rate and unusual motion among surrounding stars led us to wonder if something unusual had happened to this star in the early stages of its existence. We were suspicious,” says Philip Dufton of Queen's University Belfast, Northern Ireland, UK, lead author of the paper presenting the study's findings.
The peculiar velocity of VFTS 102 indicates that the star may have been ejected from a binary system after its companion exploded as a supernova. Such stars, accelerated due to the “sling effect”, are called runaway stars. The idea that VFTS 102 is a runaway is supported by observational evidence: a pulsar and an associated supernova remnant have been discovered in the vicinity of VFTS 102.
The fastest rotating star in the artist's depiction. The massive and bright young star VFTS 102 is spinning at 2 million kilometers per hour, or more than 500 km/s! Centrifugal forces distort the spherical shape of the star, forming a thin disk of hot plasma at the star's equator. The star may have spun up by receiving material from a companion that likely exploded as a supernova and ceased to exist.
Astronomers have found the fastest-rotating star ever discovered. The hot blue giant spins at a breakneck speed of -1 million mph (1.6 million km/h), or 100 times faster than our Sun. The star is close to the point where it will begin to collapse due to centrifugal forces.
Two researchers from the Space Telescope Science Institute in Baltimore, Maryland, Selma de Norquay and Daniel Lennon, are part of international group astronomers who used the European Southern Observatory's Very Large Telescope on Cerro Paranal in Chile to find a massive, bright young star called VFTS 102. It lies in a nearby dwarf galaxy, the Large Magellanic Cloud, about 160,000 light-years from Earth. Astronomers believe it may have been ejected from the binary star system due to the explosion of its satellite.
Astronomers also discovered that the star, which is about 25 times the mass of the Sun and 100,000 times brighter, was moving through space at a speed significantly different from its neighbors.
"The remarkable rotation rate and unusual motion compared to surrounding stars led us to believe that this star had an unusual early stage of life," said Philip Dufton of Queen's University in Belfast, Northern Ireland. "It was suspicious."
This difference in speed may mean that VFTS 102 is a runaway star - a star that was ejected from a binary star system after its companion exploded like a supernova.
The team suggests that the star may have started its life as one of the components of a binary star. If both stars were so close to each other that the companion's gas could be transferred to the other, then the stars would spin faster and faster in the process. This would explain one unusual fact - why it rotates so quickly. After a short life of about 10 million years, the massive satellite exploded as a supernova. The explosion caused the star to eject and may explain the second anomaly - the difference between the speeds of other stars in the region. When it exploded, the massive satellite then turned into a pulsar. Interestingly, there is a supernova remnant and a pulsar nearby. But it is not yet clear whether they are related to VFTS 102.
But astronomers cannot be sure that events unfolded exactly according to this scenario. "It's a fascinating story because it explains every one of the unusual features we saw," Dufton said. "This star shows us an unexpected side to the star's short but dramatic life."
To test this theory, scientists are using the Hubble Space Telescope to make precise measurements of the star's motion through space.
In Hawaii, astronomers discovered a star that became a record holder in its own way among the luminaries of our Galaxy. It is moving at an unprecedented speed of 1,200 kilometers per second, or 2.7 million kilometers per hour, which is about 750 kilometers per second faster than the average stellar speed in the Galaxy.
Its speed is so high that the star literally resists the gravitational force of the Milky Way and “escapes” from it. Unlike others, this one is compact celestial body, as scientists have found, was expelled by a very powerful thermonuclear supernova explosion.
Most stars, including our Sun, rotate around their axis at moderate speeds. Only some stars rotate when they rotate - they do not rotate in a specific orbit, but avoid the gravitational force of galaxies.
Usually, such stars are ejected from our Galaxy, as scientists suggest. Often, when a binary star system approaches a supermassive black hole too quickly, the intense gravitational field tears the pair apart - one star falls inside the hole, and the other is thrown into intergalactic space.
(photo by NASA/CXC/U.Texas).
A team of astronomers led by Stephan Geier of the European Southern Observatory observed the star, known as the hot subdwarf O US 708, using the Ecellette spectrograph and the thermal imager of the 10-meter Keck II telescope. The star itself was discovered 10 years ago and appears to be the remnant of a red giant that has been stripped of all its hydrogen - leaving only a dense, hot helium core about a third the mass of our Sun.
Scientists measured the distance to the star and its current rotation speed (more than 100 kilometers per second). They then compared the resulting coordinate measurements with the Pan-SRARRS1 digital archives and calculated the tangential component of the star's velocity.
Combining all the measurements, the team determined that the star is currently moving at a speed of 1,200 kilometers per second, which is much faster than the speeds of other known travel stars that have roamed the Milky Way. More importantly, the trajectory of US 708 indicates that the supermassive black hole at the center of the Galaxy could not have caused the development of such a high speed of the subdwarf.
“US 708 clearly did not escape from the galactic center, and there is definitely no second supermassive black hole in our Galaxy,” Geyer comments. “Smaller black holes formed during the collapse of a massive star cannot do such a job.
(illustration ESA/HUBBLE, NASA, S. GEIER).
The body of US 708 is a rapidly rotating compact helium star that most likely formed by interacting with another star, meaning it was originally part of an ultra-compact binary system, exchanging helium with a massive white dwarf.
Ultimately, this proximity led to a thermonuclear explosion of a Type Ia supernova. Due to the detonation, the subdwarf US 708 was expelled and began to travel at high speed through the Galaxy, and the binary system disintegrated. The high rotation speed of the US 708 supports this theory.
The results of these observations prove the connection between helium stars and thermonuclear supernovae. Astronomers consider them a step toward understanding the events preceding these mysterious explosions. Although the bright explosions of Type Ia supernovae are used to measure the accelerating expansion of the Universe, the reasons for their occurrence are still unknown.
As for the star US 708, it will leave the Milky Way in about 25 million years, cool over time and turn into a white dwarf. The results of the study are described in an article published in the journal Science.
Loeb and Guilshon calculated that a supermassive black hole merger would eject stars at a wide range of velocities. Few of them would reach near-light speed, but the rest would accelerate quite seriously. For example, Loeb says, there may be more than a trillion stars in the observable Universe that move at 1/10 the speed of light, or about 107,000,000 kilometers per hour.
Because the motion of a single isolated star through intergalactic space will be quite dim, only powerful future telescopes like the one scheduled for launch in 2018 will be able to detect them. And even then, most likely, such telescopes will only be able to see stars that have reached our galactic environs. Most ejected stars likely formed near the centers of galaxies and were ejected shortly after their birth. This means that they travel for most of their life time. In this case, the age of the star will be approximately equal to the time that the star travels. By combining travel time with measured speed, astronomers can determine the distance from a star's home galaxy to our galactic neighborhood.
If astronomers can find stars that were ejected from the same galaxy at different times, they can use them to measure the distance to that galaxy at different points in the past. By looking at how this distance has changed over time, it will be possible to determine how quickly the Universe is expanding.
Two merging galaxies
Ultrafast wandering stars may have other uses. When supermassive black holes collide with one another, they create ripples in space and time that display intimate details of the black hole merger. The eLISA space telescope, scheduled for launch in 2028, will detect gravitational waves. Since ultrafast stars form when black holes are about to merge, they will act as a kind of signal that will point eLISA to possible sources gravitational waves.
The existence of such stars would be one of the clearest signals that two supermassive black holes are on the verge of merging, says astrophysicist Enrico Ramirez-Ruiz of the University of California, Santa Cruz. Although they may be difficult to detect, they will represent a fundamentally new tool for studying the Universe.
In 4 billion years, our galaxy will collide with the Andromeda galaxy. The two supermassive black holes at their centers will merge, and the stars may also be ejected. Our Sun is too far from the center of galaxies to be ejected, but another star may hold habitable planets. And if people still exist by then, they could potentially land on this planet and go to another galaxy. Although, of course, this prospect is more distant than any other.
