Tycho supernova, also known as "SN 1572",CassiopeiaB,It's a star that appears in CassiopeiaSupernovaIs one of the few supernovae that can be seen with the naked eye.It was signed by Denmark on November 11, 1572astronomerTycho Brahe (Tycho Brahe) first observation[1]At that time, it was brighter than Venus. As the brightness became darker, two years later, in March 1574, it was no longer visible to the naked eye.Cassiopeia has another famousSupernova remnant: Cassiopeia A.
As a dimNebulaThis supernova site was observed by scientists with the telescope of Paloma Observatory in the 1960s;After, forRoentgen satellite(ROSAT).This supernova may belong to Ia supernova: it was originally a white dwarf star, because the material obtained from the companion star made the mass exceed the Chandraseka limit, and then burst.Such supernova explosions generally do not generate spectacular nebulae like type II supernova explosions, such as those generated by SN 1054Crab Nebula。The shell gas of SN 1572 is still erupting outward from the center at a speed of about 9000 kilometers per second.
First discovery
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On the night of November 11, 1572, Tycho (1546-1601) discovered a new star, namely "Tycho Nova".The nova is in Cassiopeia and can be seen at its brightest even in the daytime. After a period of observation, Tycho published a detailed paper "Nova".Tycho observed a supernova in the Milky Way. Since then, only in 1604 has another supernova appeared in the Milky Way.
In fact, this star was discovered by people from many countries in the world three days earlier, that is, November 8, 1572.These countries include China.brightLongqingOn the night of the third day of October (November 8) of the sixth year, Chinese astronomical officials (Imperial College) found a particularly bright "guest star" in the "wall" constellation in the northeast of the sky. When the guest star appeared, it was as big as a bullet and slightly glowing;After 19 days, it became orange and radiant, as big as a lamp, and could be seen before sunset.He was ten years oldMing ShenzongZhu Yijun (1563-1620) had just ascended the throne. When he saw the star, he thought it was a warning from heaven, so he knelt down and prayed in the open at night.The star turns dark in February of the second lunar year and disappears in April of the third lunar year.[2]
The number of supernovae has been growing rapidly.In ancient times, only supernovae in the Milky Way could be seen and recorded.After the invention of the astronomical telescope, astronomers discovered a supernova every few years, several or dozens of supernovae every year, and then broke through 100.Since a few years ago, thousands of supernovae have been discovered every year.In 2022, hundreds of thousands of supernovae can be found every year after the operation of the LSST, an 8-meter diameter large sky survey telescope jointly led by several American astronomical institutions.The 2.5 meter aperture optical survey telescope jointly developed by the University of Science and Technology of China and the Zijinshan Observatory of the Chinese Academy of Sciences will also find a large number of supernovae in the northern hemisphere.From this perspective, supernovae are not rare.
But supernovae in the Milky Way are rare.In 410 years from the invention of the telescope (1609) to the present, humans have never found any supernovae in the Milky Way.During this period, all the supernovae discovered by human beings were outside the Milky Way, and the only one that could be seen directly with the naked eye was SN 1987 A, which was observed in 1987. It exploded in the Large Magellanic Cloud (LMC), which is one of the "satellite galaxies" in the Milky Way.[2]
The nova and supernova mentioned here are two special types of stars, which cannot be interpreted as "new" born stars.Before a star explodes, it is often inconspicuous, and even a large telescope may not be able to see it.Once a sudden eruption occurs, the brightness rapidly increases thousands to tens of thousands of times in a few days or a shorter period of time, and then gradually recovers to the state and brightness before the eruption in several months to several years.When a supernova explodes, its brightness can increase ten million times to hundreds of millions of times, which is the most violent explosion phenomenon known in the stellar world.The result of the explosion is that the star loses most of its mass and collapses into a very dense object such as a neutron star, entering the final stage of evolution.Supernova explosion means the disintegration of stars and tends to be a form of death.
In 1576, he was granted the King of DenmarkFriedrich II With the support and invitation of Tycho, Tycho came to Wen Island, an island in the Baltic Sea, where he built a grand and well equipped observatory, which was called Astronomical Castle by Tycho.There are some of the best instruments at that time, mainly quadrant.
Tycho is a diligent and outstanding observer. He uses many large-scale precision products made by himselfAstronomical instrument, has been continuously observed for 20 years, and has accumulated a large number of celestial body orientation measurement data, and the accuracy of these data is second to none, greatly exceeding the observation level of previous and contemporary people.It is said that the error of his determination of the position of each planet does not exceed 0.067 degrees.The apparent diameter of the full moon is about 0.52 degrees, and the accurate observation of Tycho almost reaches 1/10 of the apparent diameter of the full moon, which is almost the limit of naked eye observation.
In 1577, he also observed a brightcomet。At that time, many people thought that comets were just some kind of optical phenomenon in the earth's atmosphere, but they could not provide evidence.Tycho confirmed that the orbit of the comet is far away from the orbit of the moon, and it can never be an atmospheric phenomenon.
For a long time, the Astronomical Castle was not only a scientific research center, but also a place where many important people came to visit.However, when Frederick died, the funding of the Astronomical Castle was difficult, and Tycho had to leave the Astronomical Castle.The last observation Tycho made there wasMarch 15, 1596。After that, the Astronomical Castle was abandoned. To this day, there is only a grassland and a Tycho statue.
In 1599, Tycho came to Prague from Denmark and served as the emperor of King Rudolph IIastronomer, continue to work tirelessly on astronomical observation.He did something decisive to the development of astronomy later here, that is, he invited a young German astronomer Kepler to be his assistant.
Discoverer
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Tycho Brahe
Tycho Brahe (1546-1601), Danish astronomer andAstrologer。December 14, 1546BornScaniaA noble family in Kiudstrup, whose father was a lawyer.His uncle had no children, so he simply stole him when he was one year old, but he was later allowed to raise the child.On October 24, 1601, Tycho died in Prague at the age of 57.
Tycho entered in 1559University of CopenhagenRead books.In August 1560, he observed once according to the forecastsolar eclipseThis made him have a great interest in astronomy.In 1562, Tycho transferred to the University of Leipzig in Germany to study law, but he used all his spare time to studyastronomy。In 1563, Tycho observed Jupiter and Saturn (the two planets are close together in the sky), and wrote his first astronomical observation data. At the same time, he noticed that the time when the merger occurred was one month earlier than predicted in the ephemeris.He realized that the ephemeris used at that time was not accurate enough, so he began long-term systematic observation and wanted to compile a more accurate ephemeris by himself.In 1566, Tycho began to wander around the world and studied astronomy at Rostock University in Germany.From then on, he began his lifelong astronomical research and made great achievements.
After continuing to study in Basel and Augsburg, Tycho returned home because his father was ill.On November 11, 1572, he saw a new bright star in Cassiopeia, so he used his own instrument to make a series of observations on this star until it1574In March, it darkened until it was out of sight.After 16 months of detailed observation and records, amazing results have been achieved, which has completely shakenAristotleThe theory that celestial bodies remain unchanged has opened up a new field for the development of astronomy.
Tycho fell out with his noble family because of his marriage to a peasant girl. He was glad to accept the proposal to give lectures in Copenhagen and Germany.He considered settling in Switzerland, but in 1576, King Frederick II of Denmark granted him the island of Wen as the site of a new observatory and promised him a living allowance.So Tycho in Denmark andSwedenWendao Island started to build a "Heaven Watching Castle".This is the earliest large-scale observatory in the world, where four observatories, a library, a laboratory and a printing factory are set up, equipped with complete instruments and costgoldMore than 1 ton.Till 1579, Tycho worked here for more than 20 years and made a series of important achievements, creating a large number of advanced astronomical instruments.The most famous one is the observation of two bright comets in 1577.He came to the conclusion that the comet was many times farther than the moon through observation, which had a great impact on helping people correctly understand astronomical phenomena.
After the death of King Frederick II of Denmark in 1599, Tycho moved to Prague and established a new observatory with the help of the Bohemian Emperor Rudolph II.In 1600, Tycho met Kepler and invited him to be his assistant.When Tycho died the next year, Kepler took over his work and inherited his courtmathematicianPosition of.Tycho's large amount of extremely accurate astronomical observation data created conditions for Kepler's work. His Rudolphine Tables, which was compiled by Kepler and published in 1627, became the most accurate astronomical table at that time.
Tycho was an outstanding observer, but his view of the universe was wrong.Tycho himself did not accept the idea of any earthquake.He thought that all the planets moved around the sun, and the sun led the planets around the earth.His system belongs to geocentric theory, which was once accepted after it was introduced into China in the early 17th century.
New exploration
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The discovery of Tycho supernova has changed people's understanding of the universe for 2000 years.For a long time, people have been affected byAristotleThe impact ofsunlight、moonas well asstarAll revolve around the earth.In 1572 AD, Danish astronomer Tycho Brahe found a bright new star in the sky.Strangely, the movement of this star is not related to other stars, which indicates that the position of this star is far beyond the space recognized by Aristotle.This discovery not only invalidated Aristotle's view, but also brought Tycho's research to a new height.This nova is the Tycho supernova.
Through detailed comparison with the spectra of supernovae that occurred outside the Milky Way in the past, researchers confirmed that Tycho supernova explosion belongs to the standard thermonuclear explosion supernova explosion.The absolute level of thermonuclear explosive supernovae when reaching the maximum luminous intensity is almost certain, which makes thermonuclear explosive supernovae widely used as a standard light source to measure the distance to distant galaxies.Previously, people inferred Tycho according to some observationssupernova remnant The distance from the earth ranges from 7000 light years to 16000 light yearsLight yearThis research result enables scientists to determine that Tycho supernova is about 12000 light-years away from Earth.
Tycho supernova remnant SN 1572,NASAThe Spitzer and Chandra Space Observatory astronomers used infrared and X-ray observations to obtain, at the Calaato Observatory in Spain, the explosion left a thermal cloud (green and yellow).The shock wave of the explosion can be seen as a blue ball of super high-energy electrons.This supernova may belong to Ia supernova, which was originally aWhite dwarf, because the material obtained from the companion star makes the mass exceed the Chandraseka limit, and an explosion occurs.Such supernova explosions generally do not generate spectacular nebulae like Type II supernova explosions, such as the Crab Nebula generated by SN 1054.The shell gas of SN 1572 is still erupting outward from the center at a speed of about 9000 kilometers per second.
Tycho supernova type
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An international research group participated by the National Astronomical Observatory of Japan published a paper in the British journal Nature on the 4th, saying that their spectroscopic observation of the "echo" of visible light found around the Tycho supernova debris showed that the supernova explosion observed by the Danish astronomer Tycho Brahe in 1572 belonged to the standard thermonuclear explosion type (type Ia)Supernova explosion
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This research was jointly completed by the National Astronomical Observatory of Japan and the Max Planck Institute of Astronomy in Germany.Astronomers mainly used the so-called "echo" phenomenon of light in this observation and research.This summer, the research team used the 3.5-meter telescope of the Max Planck Institute of Astronomy and the "Pleiades Cluster" telescope of Japan to search around the area where the "echo" of light was reported in the past, and finally captured the faint diffuse light.After spectral analysis, the researchers concluded that the faint light came from the supernova explosion, and it was the light generated by the supernova explosion in the direction of Cassiopeia observed by Tycho more than 400 years ago.
significance
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Many people believe that Tycho's most influential event in the history of astronomy occurred in his later years, which is not very tenable.Tycho's greatest feat in his middle age - observing the supernova in 1572 and the comet in 1577 - was the most revolutionary action in astronomy at that time.In Europe at that time, although Copernicus had put forward his heliocentric universe model, the traditional "crystal ball" universe system still occupied the position of the official doctrine of the church.This cosmic system was established by Aristotle on the basis of the work of the ancient Greek astronomers Eudoxus and Callippus. It has the following main points:
1、 The earth centered celestial bodies (including the moon, the sun, the five planets and the stars) attach to their respective spheres and are carried around;
2、 These spheres belong to entities and are composed of substances that are immortal, completely transparent and impenetrable - hence the name of the crystal sphere;
3、 The whole universe is limited and closed;
4、 The part above the lunar orbit is the eternal sacred world, and only the "world under the moon" is the changeless and "perishable" world.
This means that such celestial phenomena as nova explosion, comet and meteor can only be phenomena in the atmosphere.
Tycho did not advocate the theory of heliocentric geodynamics. His universe system was a compromise between the Ptolemaic system in the geocenter and the Copernican system in the heliocentric.He also has no intention of becoming the enemy of Aristotle in philosophy.But he actually gave the crystal ball system a fatal blow.
In November 1572, a new star appeared in Cassiopeia, bright enough to be seen in broad daylight.Such a strange celestial body originally appeared in the sky, and the world could see it. Astronomers, astrologers, or, more generally, any "natural philosopher" of that era could observe it.However, this new star is called "Tycho supernova" in the history of astronomy, because Tycho made extremely detailed observations and azimuth measurements on it.
Tycho repeatedly observed the nova by various methods and found that it neither has parallax (which indicates that it is very far away from the Earth) nor moves its position.So his final conclusion is that this nova is located in the celestial sphere of the star.
For the modern stellar evolution theory, both nova and supernova explosions are normal phenomena, which are the later years of a star in its life.For the ancient Chinese, the world was full of wonders, and the emergence of new stars, which were often called "guest stars" in ancient China, would not conflict with any doctrine or ideology.But in the European intellectual circles at that time, Tycho's conclusion was no less than a thought bomb!Because this conclusion directly challenges the Aristotelian crystal ball system as the official theory of the church - according to the theory of the crystal ball system, the celestial sphere of stars belongs to the unchangeable region for ages, and nova can only appear in the "world under the moon".
However, when his observation results were published the following year, Tycho himself had not completely broken away from the crystal ball system.Although he has objectively opened the door for this supernova to rebel against Aristotle's dogma.
However, the great comet of 1577 appeared again.
In a painting printed in Prague at that time, the tail of this bright comet was depicted stretching from Saturn to the moon.At this time, Tycho has become the owner of Wen Island. All kinds of newly built astronomical instruments and a group of student assistants on the island, of course, should be mobilized to observe and measure this new astronomical phenomenon that shocked the whole world - the observation of Wen Island made this comet named "Comet Di Gu" in the history of astronomy.
Tycho began to observe this big comet on November 13, 1577, and lasted until January 26, 1578. At this time, the comet was far away and could hardly be recognized by the naked eye.In the observation, Tycho used a semicircle, a chronometer and a quadrant with a horizon circle.He also observed and calculated the position of the comet day by day to calculate the speed of the comet.
Aristotle's doctrine on comets has never been severely challenged before.According to this doctrine, the element of comet is fire.In Meteorology, Aristotle believed that all the fire elements and most of the gas elements below them were driven by the rotating celestial bodies. Sometimes, because of the movement of a specific star or planet, "no matter where it is connected during this movement, it is often ignited", which formed various meteors and comets and other celestial bodies.
In this way, comets are certainly not celestial bodies. Comets are considered to be composed of "earth materials", so their research is not astronomy, but "metaphysics".Because of their deep belief in Aristotle's dogma, European astronomers seldom measured the height of comets when observing them, because the answer was preset - under the moon.But Tycho's observation proved that this kind of astronomical phenomenon occurred on the lunar sky.
The observation of Tycho shows beyond doubt that the comet travels in interplanetary space and passes between the orbits of planets.That is to say, this comet is effortlessly passing through the "completely transparent and impenetrable" celestial sphere that was previously thought to carry planets!This made Tycho understand that these celestial spheres did not actually exist.The conflict between these facts and the crystal ball system was more serious and direct, which finally prompted Tycho to abandon the crystal ball system.In 1588, he published On the New Celestial Phenomena（De mundieatherei recentioribus phaenomenis）A book, which builds a new cosmic system on the basis of observation, clearly points out that:
There really is no sphere in the skyOf course, almost all ancient and many modern philosophers have no doubt that the sky is made up of impenetrable objects and divided into many spheres, and the celestial bodies attach to it and move with these spheres.But this view is not consistent with the facts.
Tycho's observation of supernovae and big comets was the most powerful blow to the crystal ball doctrine at that time.For other objections, defenders of the crystal ball system can find excuses, but it is difficult to avoid the observation facts provided by Tycho unless they deny the observation facts themselves.
The defenders of Aristotle's theory soon realized this, and some people did try.For example, S. Chiaramonti, one of Galileo's censors appointed by the Pope, wrote two books for this purpose decades later, trying to take drastic measures and directly deny the observation results of Tycho.In 1621, he published Anti Tycho Theory（Antitycho）, asserting that Tycho's comet is still in the "world under the moon", while Tycho's supernova is not a celestial body at all;In 1628, he also published "Three New Stars"（De tribus novis stellis）Tycho supernova is also in the "world under the moon".Galileo once refuted Qi's above fallacy in his book A Dialogue on the Two World Systems of Ptolemy and Copernicus.By this time, Kepler's three laws of planetary motion had been published for many years, and Galileo's telescope observation results had also been published for ten or twenty years. The rebellion against Aristotle's theory had been in full swing, and Qi's book could not save the fire at all.
Other supernovae
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1987A supernova
1987A supernova
Since the discovery of Ophiuchus supernova in 1604, people have never seen a supernova with the naked eye for more than 400 years.On February 23, 1987, a Canadian astronomer found a class 5 star in the Large Magellanic Cloud. It was soon confirmed to be a supernova, which immediately caused a sensation in the world's astronomical circles.In the following months, this supernova, called 1987A, was always shining brightly, with brightness equal to 100 million suns.So this supernova, numbered 1987A, quickly became the most thoroughly studied supernova in history.The supernova is located in the Large Magellanic Cloud 163000 light years away from Earth.In fact, it erupted around 161000 BC, but its light did not reach the Earth until 1987.The 1987A supernova remnant photographed by the Hubble Space Telescope in December 2006.
Andromeda S supernova 1885A
Andromeda S supernova (1885A)
Before 1885, the few supernovae observed by human beings were relatively close to the Earth, and Andromeda S supernova was the first supernova discovered outside the Milky Way and the only supernova discovered in Andromeda.In 1885, an Irish astronomer saw a bright reddish object in the sky.This object is the 1885 supernova.The 1885 supernova comes from the Andromeda galaxy, so it is also called "Andromeda S supernova", about 2.5 million light years away from Earth.However, a few months later, the supernova began to disappear, and it was not until 1989 that astronomers found its remnants again.
Kepler supernova 1604
Kepler supernova (1604)
Kepler, a German astronomer, was a student of Tycho Brahe, a Danish astronomer. He followed his teacher's footsteps to find a supernova. He also found a supernova.In October 1604, Kepler found a new luminous object in the sky.This is also a supernova visible to the naked eye, numbered 1604.From 1604 to 1606, Kepler had been studying his supernova until it disappeared in 1606.Since the astronomical telescope was not invented until 1609, Kepler's research mainly relied on naked eye observation.Kepler supernova is also the last supernova that can be observed with the naked eye in 400 years.Kepler supernova is about 13000 light-years away from the Earth, which is the representative of the recent supernova explosion in the Milky Way.
Guest 185
Visitor (185)
The earliest record of supernova explosion in human history can be traced back to AD 185.According to the "Later Han Dynasty Book", ancient Chinese astronomers discovered a "guest star" in the sky as early as 185 years ago.Astronomers described the supernova in this way, "showing colorful colors and gradually disappearing into the sky after seven months." Later, some astronomers thought that it was just a comet, but more people insisted that it was a supernova.
