On July 23, 1995, Alan Hale and Thomas Bopp of the United States independently discovered thecomet。It is the farthest comet from the sun (found outside the orbit of Jupiter) among many comets discovered by amateur astronomers.If Halley's Comet is placed in the same orbit as it, the luminosity ratio of Hale Bopp CometHalley's CometBrighten thousands of times.
Comet Hale Bopp(English:Comet Hale-BoppNo.:C/1995 O1）It's aLong-period comet, passed perihelion on April 1, 1997[1]。
On July 23, 1995, Alan Hale and Thomas Bopp of the United States independently discovered the comet.It is the farthest comet from the sun (found outside the orbit of Jupiter) among many comets discovered by amateur astronomers.If Halley's Comet is placed in the same orbit as it, Hale Bopp's Comet is thousands of times brighter than Halley's.
Generally, comets are relatively inconspicuous outside the orbit of Jupiter, but comet Hale Bopp is an exception - when the comet passes the perihelionluminosityIt is - 1.4, and can be seen with the naked eye even in the city. It is the brightest comet since 1975, and therefore it has become one of the most spectacular comets in the past 20 years.according toHubble Space TelescopeHale Bopp comet is a large comet with a diameter of about 40 kilometers.
According to preliminary calculation, Comet Hale Bopp will return more than 2000 years later (until January 2006, there were still Japanese astronomersAustraliaThe comet was photographed).
In the early morning of July 23, 1995, the United StatesNew MexicoAlan Hale ofcometIn the middle of the gapreflectorAlignedSagittariusM70, immediately noticed a blurry light and shadow appeared. In the field of vision, he was an experienced comet observer, so he immediately guessed that this might be a new comet.After measuring the luminosity and position of this celestial body, Haier immediately usedInternational Astronomical UnionThe computer program for identifying the comet confirmed that no one had discovered and reported the new object, so it immediately sent a telegram to inform the International Astronomical Union that there was a new objectCometStellar integumentfindYes!Almost at the same time,ArizonaThomas Bopp also just observedM70He also noticed thisstar mapLater, a telegram was sent to ask the International Astronomical Union to confirm the objects that could not be found in the.Since the two men found the comet in a very short time intervalcometIt is called Hale Bopp Comet, also known as Hale Bopp Comet.It is numbered 1995 O1, indicating that it was the first comet discovered between July 16 and 31, 1995.
Orbital period
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The comet's last regression may have occurred 4200 years ago, and its orbit is perpendicular to the ecliptic.
In March 1997, it was 0.77 away from JupiterAstronomical unitEnough to be changed by Jupiter's gravity.The orbit was shortened, the Haier Bopp revolution period was shortened to 2380 years, and the aphelion was also shortened to 360 astronomical units, with a difference of about 525 astronomical units.
During the passage of comet Hale Bopp through perihelion, many astronomers made in-depth observations on it, and the results added a lot of new information to comet science.
The tails of ordinary comets are mostly composed of gas and dust, but the tails of Comet Hale Bopp contain the metal element sodium, which can only be observed with powerful instruments.It has been observed beforeMetallic sodiumIt was first discovered that metals were released from comets, but metals were released from comet tails, so this is one of the most exciting discoveries.The comet tail includesNeutral atomIts length can reach 50 million kilometers.
It is observed that the metal sodium of the comet comes from the inner layer of its comet andCometary nucleusThere are also several principles that can explain the release path of sodium atoms, including the collision of dust particles surrounding the comet nucleus, and the ultraviolet light ejecting sodium from the dust particles. However, it is unknown how the comet's sodium is ejected.
The comet'sDust comet tailBack to its orbit, gasCometary tailAnd the direction of sodium comet tail is between the two, indicating that sodium atoms are transferred fromCometary headReleased from.
Basic information
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After the discovery of Comet Hale Bopp, astronomers found that this comet was obviously different.
First of all, he is in Jupiter andSaturnBetween orbits, seven from the sunAstronomical unitIt is found that comets are very sluggish outside the orbit of Jupiter and difficult to distinguish from asteroids. The abnormal activity of Hale Bopp makes himAmateur astronomerThe farthest comet found.
In addition, the brightness when he was found wasHalley's CometAt the same distanceA thousand timesSo he is supposed to be a huge and active comet.Generally, the solid part of a comet is not very large, and it is generally believed that from one kilometer to one hundred kilometers is a reasonable size.The famous Comet Halley was measured to be about eight to sixteen kilometers in size through close observation by spaceship. According to the luminosity of Comet Hale Bopp, its diameter may be forty kilometers, and it is a very huge comet.SpaceA sheet issued by the General AdministrationSpace telescopeThe photo taken on September 26, 1995 shows the abnormal light increase of the comet, which has aroused the interest of observation.
The orbit of Comet Hale Bopp returns to the sun once in 3000 years. Astronomers believe that it is no longer a so-called "virgin" comet - because the new comet returns for the first time (or the first few times). The comet is surrounded by dust and gravel, and the internal matter is not easy to volatilize and brightCometary tailAs a result, it is not very spectacular.
Unexpected discovery
This comet was discovered by amateur astronomers for the first time due to "accident" since July 1975.In other words, neither of the two named discoverers was a "deliberate" comet searcher. They were just looking at the stars for fun and found them by accident.
Approaching the sun
Comet Hale Bopp attracted much attention in early 1997.In the summer of 1996, Comet Hale Bopp became visible to the naked eye.In the second half of the same year, the increasing speed of its luminosity slowed down, but scientists were still optimistic and waiting for the comet to become brighter.By December 1996, due to itscelestial sphereThe position is too close to the sun, so it cannot be observed temporarily. In January 1997, the comet reappeared and has become brighter. It is also easy to find it in the city night sky polluted by light damage.
Various comet charts of Haile Pope
With the popularization of the Internet, many websites follow the comet trend and provide the latest pictures every day, which greatly increases the visitor traffic of these websites.The Internet plays a major role in promoting the news of the comet to the public.The comet continued to approach the sun, and its luminosity continued to increase. By February 1997, it had reached the second grade, and its blue color facing away from the sun could be clearly seenCometary tail, leaving pale yellow cometary dust on the track.March 9, MongoliaSiberiaEastern and ChineseMohe CountyVisible onceTotal solar eclipseThe rare observation of "total solar eclipse and comet watching together" attracted astronomers all over the world to watch and take pictures in the cold. China issued a commemorative cover with it. CCTV broadcast live in nine cities including Mohe that morning, which was the first of its kind.
On April 1 of the same year, the comet passed through the perihelion, and its brightness was brighter than many stars, second only to Sirius.Its twoCometary tailIt extends to 30-40 ° of the night sky.At that time, because the perihelion of the comet was far away from the sun, it could be seen before the twilight disappeared every night in the sky, while many other comets could only be observed for a short time after sunset because their perihelion was close to the sun.Observers in the northern hemisphere can see the comet all night long.
Photometric transition
After passing the perihelion, the comet moved to the southern half of the celestial sphere. Observers in the southern hemisphere saw that the comet began to darken from the summer to autumn of 1997. After December 1997, it could not be seen with the naked eye. The duration of observation without instruments lasted 569 days (18.5 months), breaking the year 1811Big cometIts visual time lasted for 9 months.
After the comet left the sun, it continued to darken. Astronomers were still tracking it. As of January 2005, it had exceeded the orbit of Uranus (21 AU). Large telescopes can still be used for observation. Until recent results showed that it was still releasingCometary tail。
Astronomers predict that before 2020, the comet can still be observed with powerful telescopes when its luminosity is within 30 degrees, and then it will be difficult to distinguish it from distant galaxies with similar luminosity.According to the available data, it may return around AD 4380.
Track change
The comet's last regression may have occurred 4200 years ago, and its orbit is perpendicular to the ecliptic.
In March 1996, it was 0.77 away from JupiterAstronomical unitEnough to be changed by Jupiter's gravity.Its orbit is shortened, and itsRevolution periodIt was shortened to 2380 years, and the aphelion was also shortened to 360 astronomical units, with a difference of about 525 astronomical units.
During the passage of comet Hale Bopp through perihelion, many astronomers made in-depth observations on it, and the results added a lot of new data to comet science.
Sodium comet tail
Comet Hale Bopp
General cometaryCometary tailIt is mostly composed of gas and dust, but the tail of Comet Hale Bopp contains the metallic element sodium, which can only be observed with powerful instruments.It has been observed beforeMetallic sodiumIt was released from a comet, but it was the first time that it was released from a comet tail, so this is one of the most exciting discoveries.The comet tail includes neutralatomIts length can reach 50 million kilometers.
It is observed that the metal sodium of the comet comes from the inner layer of its comet andCometary nucleus, and the release path of sodium atoms can also be explained by several principles, including the impact of dust particles surrounding the comet nucleus, and the ultraviolet radiation ejecting sodium from the dust particles, but it is not known how the comet's sodium is ejected.
The comet'sDust comet tailBack to its orbit, gasCometary tailThe direction of sodium comet tail is between the two, which means that sodium atoms are transferred fromCometary headReleased from.
Deuterium element
The comet'sDeuterium elementIts compounds include heavy water, the content of which is twice that of the earth's oceans. Therefore, it can be inferred that although a comet hitting the earth can bring an appropriate amount of water for the earth, if other comets contain a lot of heavy water, the comet will not be the only water source for the earth.
Comet Hale Bopp
In addition, people also found a lot of heavy hydrogen in the hydrogen compounds on the comet, and the proportion of heavy hydrogen and general hydrogen is different in different compounds, which led astronomers to believe that the comet's ice was formed in the interstellar cloud, rather than in theSolar nebula。It is estimated that the cometInterstellar cloudWhen ice is formed, its temperature is between 25-45K.
Organic matter
Through spectral observation, it was found that the comet contained many organic compounds, many of which were discovered for the first time.Their molecules may be hidden inCometary nucleusInside,CometThe activity of may cause them to produce a combination.
rotation
Scientists observed that the comet did not eject gas evenly, but ejected from a specific location. They calculated its rotation period of 11 hours and 46 minutes by observing the change of the eruption location, and then found that it had more than oneAutorotation shaft。[2]
Double comet nucleus theory
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Comet Hale Bopp
In 1999, a paper hypothesized that there were two comets Hale BoppCometary nucleusTo explain the form of dust it emits.This paper is purely a deduction. The author has not observed and made the structure of its twin cometary nuclei, but he estimated that the diameter of one of the cometary nuclei is about 30 kilometers, while the diameter of the main cometary nucleus is about 70 kilometers. They are about 180 kilometers away and revolve around each other in a three-day cycle.
This paper has attracted controversy from many astronomical observershubble space telescope Making observations, we can't find any pairsCometary nucleusEvidence.Because when a comet splits into several pieces, their distance will be farther and farther;And so far, no comet has stable double comet nuclei;On the other hand, the orbit of a comet with two cometary nuclei is often affected byplanetGravitationalPerturbationChange and separation.
From the end of 1997 to the beginning of 1998, it was observed through the adaptive optical device that the light of its cometary nucleus appearedBimodal。However, whether this phenomenon is caused by double comet nuclei is still under debate.
Comet Hale Bopp is actually an extremely bright comet, whose brightness may beHalley's CometThousands of times.It arrived at the perihelion in April 1997. Because of its huge size, at least 40 kilometers above, its approach also brought panic to people - when it entered the inner orbit of the solar system, it triggered speculation about aliens coming to Earth.Comet Hale Bopp is probably the most popular comet in history, according toNASAAccording to the observation records of Hale Bopp, Comet Hale Bopp has two beautiful "tails" in blue and whitelight pollutionWe can also easily see it in the more serious areas.
Other guesses
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There are also alien enthusiasts and UFO fans who believe that the orbit of the comet changes too much, not because of the attraction of planets, but because the comet is a smart spacecraft from Orion.
The Great Comet of the First 44 Years (Caesar's Comet) · The Great Comet of 1106 · The Great Comet of 1402 · The Great Comet of 1556 · The Great Comet of 1577 · The Great Comet of 1680 · The Great Comet of 1729 · The Great Comet of 1744
nineteenth century
The Great Comet of 1811 · The Great Comet of 1843·Comet Donati ·The Great Comet of 1861 · The Great Comet of 1882
