Which comet was visible in 1995. One comment to “Comet Hale-Bopp and other astronomical objects visible to the naked eye”

Tailed guest over Valparola pass

Hale Bopp is one of those comets that appear over the Earth every 2500 years, and was discovered at the moment when it was already very close to the Earth.

History of the discovery of Hale Bopp

It happened on July 23, 1995, when American astronomers named Alan Hale and Thomas Bopp at the same time noticed a celestial object very close moving relative to the stars.

The astronomers decided to report this to the American Central Bureau of Astronomy. It is it that decides whether a new celestial body has been discovered. The message was immediately sent, and already on July 24 the whole planet learned about the discovery of a new comet. It bears its name in honor of the discoverers Alan Hale and Thomas Bopp.

The comet they discovered appeared above the Earth in the spring of 1996, or rather in May, and it was possible to see it without special instruments until the winter of 1997, only in December it left the sky of planet Earth. Hayla Bopp was and to this day remains the brightest of all that have been observed by scientists. With the help of complex calculations, they found out that it would be possible to see it next time only in 4390.

Alien machine? Or incredible abilities?

Hale - Bopp C/1995 O1

Comet Hale Bopp was studied by different scientists for a year and a half, as a result of which many discoveries were made, some of which caused a number of heated debates and versions. Among other things, a tail of the third type, unique in its composition, was found in this comet. Usually the tail consists of a gas and dust tail, but this time there was also a sodium tail, which scientists detected using special sophisticated technical instruments. How neutral atoms were able to form a tail remained a mystery.

Also, this comet was found to have unique properties of its nucleus; during rotation, it changed not only the axis of rotation and period, but even the direction of rotation. As a result, scientists made an assumption that it has two nuclei, but they could not prove this in other ways, nor could they refute it. There was another theory, some researchers suggested that an alien apparatus could be inside the comet, but no one could prove it.

Signal for self-improvement

Undoubtedly, the comet will go down in history as the most unique celestial body that people could observe in the 20th century, as well as the cause of mass madness on a mystical and apocalyptic wave. There were all possible legends, myths and strange stories associated with the comet. But the stories didn't stop there.

A sect called "The Gates of Heaven" led by Marshall Aprilwhite in the amount of 39 people said goodbye to life, believing in his teachings. The mentor called for a self-improvement program, after which the followers of his sect would leave their bodies and join the aliens. And the widely publicized legend that it was an alien ship hidden behind a comet became a signal for members of the sect. As a result, on March 22, 1997, the most massive suicide in US history occurred.

Comet Hale-Bopp (C/1995 O1) belongs to the class of long-period comets. It is one of the most popular sightings of the 20th century. Also, the comet is one of the brightest over the past few decades. The discoverers are two independent amateur astronomers at once, namely Alan Hale and Bopp Tom. The discovery occurred on July 23, 1995, at that moment Hale was at home and looked at the evening sky through his telescope, then he noticed a strange blurred dot among the stars. Bopp was spending time with friends in the Arizona desert, one of them brought a homemade telescope to the meeting, suddenly a bright spot flashed in the eyepiece. After checking with the ephemerides of all known space objects at that time, Bopp concluded that he had found something new. Then he simply sent a telegram to the same place as Hale.

Interestingly, the comet was found at a great distance from the Earth, at 7.2 AU. This made it possible to put forward the assumption that when approaching the Earth, it will be clearly visible in the sky. Also, C / 1995 O1 could be observed with the naked eye for a record long time, namely, for more than 18 months, anyone could see this space object. At the same time, the comet caused some confusion among people, as rumors began to spread actively that there was a UFO in its tail. They also became the main cause of mass suicides, which were committed by the followers of the "Gate of Paradise" movement.

As the comet approached the Sun, astronomers began to study very actively the materials of which it consisted. Several important discoveries have been made. The most important of these was the observation of a third type of tail. Usually such objects have only two tails - ion and dust, in this case there was a third - sodium, which astronomers could only notice using a complex system of filters and special optics. Sodium streams have been found on other comets, but they never produced a tail. In this case, the sodium tail was made up of neutral atoms and extended over 50 million km.

The main source of sodium was located inside the comet, but not in the nucleus. There are theories according to which such a source can be formed, for example, it can be collisions of dust particles, or sodium is “squeezed out” from particles under the influence of ultraviolet rays. However, it is not yet known exactly how this tail was created. In addition, scientists have found that the comet contains the following substances:

Also in 1999, there were disputes between researchers that a comet could have two nuclei at once. According to this theory, the secondary core has a diameter of about 30 km, while the main one is 70 km, while there was more than 180 km of empty space between the nuclei, and mutual circulation takes three days. Considering that the results of this assumption were based purely on theoretical knowledge, the theory of the second nucleus was subject to a flurry of criticism from practical astronomers, since their equipment could not detect it. Previously observed comets that had two nuclei were extremely unstable and quickly decayed under the influence of the gravity of neighboring stars or planets.

Already in May 1996, the comet could be seen with the naked eye, although the increase in brightness became slower closer to the second half of the year. Scientists still suggested that it would become one of the brightest. On March 23, the comet passed at a minimum distance from, only 196.7 million km. Perihelion arrived on April 1, becoming a real spectacle for all observers. The comet shone brighter than all the stars, except for Sirius, and it was already possible to consider it in the late afternoon.

The nearest perihelion will not come at all soon, since the comet needs about 2,400 years to pass its orbit.

Conclusion

Comet Hale-Bopp is a unique phenomenon that humanity will not soon forget. Thanks to the active work of the media and some sites on the Internet, a huge number of people learned about the comet. In terms of popularity, it was able to surpass Halley's comet and broke several records at once: in terms of detection range, nucleus size and brightness. It was observed about 2 times longer than the previous object of this type. In total, the discovery of this comet made several important discoveries possible, which made it possible to better understand the mechanisms by which the Cosmos functions.

> Hale Bopp

C/1995 O1 (Hale-Bopp)- long-period comet of the solar system: description, characteristics with photo, the most popular comet, Earth flyby, detection, name.

Comet Hale-Bopp became a highlight as it approached Earth in the late 1990s. The closest approach was performed in 1997. It could be watched from the territory of the Northern Hemisphere for 18 months without the use of instruments.

It is believed that this is one of the most popular comets mentioned in the media and the public. It is 1,000 times brighter than Halley's comet, and the double blue-white tail appeared even in bright skies.

Unfortunately, her arrival is overshadowed by sad events. Approximately 40 people from the "Heaven's Gate" (San Diego) committed mass suicide.

Droplet from M70 and Comet Hale-Bopp

Comet Hale-Bopp was independently discovered by Alan Hale and Thomas Bopp. At that time, it was the most distant comet found by amateur astronomers. On July 23, 1995, both pointed their telescopes at the globular cluster M70. Hale said he was surprised to see a strange object that had not been in the cluster a week ago.

The men sent the data to the Central Bureau of Astronomical Unions. It was surprising how bright comet C/1995 O1 seemed at such a great distance. They realized that as she approached, she would put on a real light show. But it is difficult to predict the behavior of a comet, because these are balls of ice and stones, the trajectory of which is influenced by other objects and events. Look at Comet Hale-Bopp in the photo.

The comet approached a maximum of 193 million km. At that time, comet Hyakutake was also present in the sky, but it was inferior in brightness, although it was located closer

Comet Hale-Bopp sparked an internet boom

The media constantly wrote about the Hale-Bopp comet, but the information also covered the Internet, which was only gaining popularity. There were so many visitors that they literally created the first traffic jam. The comet's home page was visited by 1.2 million visitors a day, which became a record for resource traffic.

The comet began to be monitored through professional equipment by connecting the Hubble Space Telescope. He showed that the core covers 30-40 km. They also recorded dust flowing out of it, which exceeded the average amount by 8 times. The surface seemed incredibly dynamic.

Comet Hale-Bopp and Heaven's Gate

Heaven's Gate is a cult led by former music professor Marshall Applewhite. He promoted sexual abstinence and castration. The participants believed that their bodies were vessels that needed to be disposed of. They believed that an alien ship would arrive after the comet.

At the end of March 1997, Applewhite and 38 followers drank poison mixed with vodka and lay down to die. The bodies were found in a mansion in the suburbs of San Diego (California).

Comet Hale-Bopp's next arrival

The arrival of Comet Hale-Bopp created an amazing show. But the analysis showed that it had already approached us 4200 years ago, which means that it will return in millennia next time. Therefore, the researchers tried to extract the maximum information from this arrival.

The first photographs of Comet Hale-Bopp appeared in 2002 from the ESA, when the comet was flying at a distance of 2 billion km. Despite the low temperature mark, it is still surrounded by a large active dust and ice core (50 km in diameter).

And one of the brightest in the last few decades. It was visible to the naked eye for a record period of 18 months, twice the previous record set by The Great Comet of 1811.

Opening

The comet was discovered independently by two American observers - Alan Hale and Thomas Bopp. Hale spent many hundreds of fruitless hours looking for comets, and near his home in New Mexico he observed already known comets, when about midnight suddenly came across a foggy object magnitude 10.5 m next to globular star cluster M70 in constellation Sagittarius. Hale first established that there were no others near this cluster. deep sky objects. Further, he found that the object moves noticeably against the background of stars (and therefore is in solar system) and wrote an email to Central Bureau of Astronomical Telegrams, which tracks astronomical discoveries .

Bopp didn't have his own telescope. He was in nature with his friends near Stanfield in Arizona, and observed star clusters and galaxies when a speck of light flickered in front of Thomas's eyes through the eyepiece of his friend's telescope. After checking with ephemeris known objects in the solar system, Bopp realized that this speck was a new object, and sent telegram the same way as Hale.

The next morning, the discovery of a new comet was confirmed, which was given the name Comet Hale-Bopp and the designation C/1995 O1. The opening was announced in circular № 6187 International Astronomical Union. At the time of discovery, the comet was at a distance of 7.1 a. e. from the sun .

The formation of the "Big Comet"

Approaching the Sun, the Hale-Bopp comet became brighter: in February it reached 2nd magnitude, and it was already possible to distinguish its tails - a bluish ion, directed in the opposite direction from the Sun, and a yellowish dust, curved along the comet's orbit. Solar eclipse in Eastern Siberia and Mongolia 9th of March made it possible to see the comet during the day. March 23 In 1997, the comet Hale-Bopp approached the Earth at a minimum distance of 1.315 AU. e. (196.7 million km).

As it passed perihelion on April 1, 1997, the comet was a stunning sight. With an average value of −0.7, it shone brighter than any star (excluding Sirius), and its two tails stretched across the sky for 15-20 degrees(and their parts invisible to a simple observer - by 30-40 °). The comet could be observed just after dusk; and although many "large" comets, passing perihelion, were not far from the Sun, the Hale-Bopp comet could be observed in northern hemisphere all night long.

Comet Hale-Bopp could be even more impressive. If she came to the same distance to the Earth as in 1996 - Comet Hyakutake(0.1 AU), it would exceed in brightness Venus, reaching −5th magnitude.

Comet Removal

After passing perihelion, the comet moved to the southern celestial hemisphere, and its brightness began to weaken. The comet looked much less impressive to southern observers, but they were able to see how its brightness gradually decreases during the second half of 1997. The last known sighting of the comet with the naked eye was in December 1997, so it was visible for about 18 and a half months. This term broke the previous record of 9 months, set by The Great Comet of 1811.

Comet Hale-Bopp is now receding, and its brightness continues to decrease. In August 2004 she flew out of orbit uranium, and as of the middle 2008 She was at a distance of about 26.8 AU. e. from the Sun. However, it is still tracked by astronomers. The reason for this is the unusually long activity of the comet. Recent observations (October) indicate that the comet still has coma brightness about 20 m . It is assumed that the reason for the unusually long activity lies in the slow cooling of the comet's giant nucleus.

The comet is expected to be observable with large telescopes until about 2020 until its brightness drops to 30 m . The comet will return to Earth around the year 4390. Comet Hale-Bopp is expected to have a 15% chance of becoming a circumsolar, and serve as the progenitor of a new family, such as Kreutz family of comets.

Orbit changes

Scientific research

When approaching the Sun, the comet was intensively studied by astronomers. In doing so, some important and interesting discoveries were made.

One of the most significant results was the discovery of a tail of the third type in a comet. In addition to the usual gas (ion) and dust tails, there was also a weak sodium visible only with powerful tools and a complex system filters. Sodium fluxes have been previously observed in other comets, but they did not form a tail in any of them. At Comet Hale-Bopp, it consisted of neutral atoms and stretched almost 50 million kilometers in length.

Excess deuterium

The comet was found to contain a high content deuterium in the shape of heavy water: almost twice as much as in terrestrial oceans. This means that although comet collisions with the Earth could be an important source of water on the planet, they could not be the only source (if, of course, such a concentration is characteristic of all comets).

The presence of deuterium in the composition of other hydrogen compounds was also found. The ratio of these elements differed in different structures, so astronomers suggested that the ices of the comet were not formed in protoplanetary disk, and in interstellar cloud. Theoretical models of ice formation in nebulae show that Comet Hale-Bopp formed at a temperature of 25-45 .

organic compounds

Comet Hale-Bopp observations using spectroscope revealed the presence of a group organic compounds, some of which have never been found in comets. These complex molecules, such as acetic and formic acid and acetonitrile, could be in the composition of the nucleus or obtained during chemical reactions.

Argon detection

Comet Hale-Bopp was also the first comet to contain noble gas argon. Noble gases are chemically inert and extremely volatile, and different gases have different boiling point. The latter property helps in tracking the change in temperature of comet ices. So, krypton evaporates at a temperature of 116-120 K, and it was found that its abundance in a comet is 25 times lower than that of the sun; on the contrary, the sublimation temperature of argon is 35–40 K, and its content is higher than that of the sun.

So it was established that the temperature of the internal ices of the Hale-Bopp comet never exceeded 40 K, and at the same time at some point their temperature was above 20 K. Unless the formation of the solar system occurred at temperatures lower than suggested in present, and with a higher initial argon content, the presence of argon in the comet means that Comet Hale-Bopp formed beyond the orbit of Neptune somewhere in Kuiper belt, and then moved to the Oort cloud.

Rotation

Ejection of matter from the nucleus of a comet.

The comet's activity and gas emissions were not equally distributed over the entire surface of the nucleus, but manifested themselves in the form of strong emissions from certain points. By observing them, it became possible to calculate the period of rotation of the comet's nucleus. It was found that the nucleus of the comet Hale-Bopp really rotates, however, at different times, different values ​​​​of the period were obtained: from 11 hours 20 minutes. up to 12 h 5 min. Superposition of rotations with several periods suggests that the comet's nucleus had more than one axis of rotation.

Another period (called the "super period"), calculated from dust emissions from the surface, turned out to be 22 days. And in March 1997, it suddenly turned out that in the interval from February to March, the comet changed the direction of rotation to the opposite. The exact reasons for this behavior remain a mystery, although it appears to have been due to strong non-periodic outbursts of gas.

Satellite controversy

In 1999, a work appeared, the author of which, in order to fully explain the observed nature of dust emission, suggested that the comet had a double nucleus. The work was based on theoretical studies and did not refer to any direct observations of the secondary nucleus. It was stated, however, that it should have a diameter of 30 km, with a main nucleus of 70 km, a distance between them of 180 km, and a period of mutual revolution of 3 days.

The provisions of this work were disputed by practicing astronomers, who argued that even photographs of the comet taken by the telescope " Hubble» high resolution, do not contain traces of a double nucleus. In addition, in previously observed cases of comets with a double nucleus, they did not remain stable for long: the orbit of the secondary nucleus was easily disturbed by the gravity of the Sun and planets, tearing the comet apart.

A few months later, in March 1997, a religious cult that called itself "Gate of Paradise" ("Heaven's Gate") , chose the appearance of a comet as a signal for a mass cult suicide. They declared that they were leaving their earthly bodies to make a journey to a ship following a comet. 39 cultists commit suicide at ranch Santa Fe (English)Russian .

Comet Legacy

Notes

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2. Calculated from future 1/a (indefinite) . OAA computing section circular NK 1553. Retrieved December 27, 2015.
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4. IAU Circular 6187: 1995 O1(English) (unavailable link - story) . International Astronomical Union (July 23, 1995). Retrieved November 10, 2008.
5. Lemonick, Michael D. Comet of the decade. Part II, Time magazine (March 17, 1997). Retrieved November 8, 2008.
6. Thomas Bopp. Amateur Contributions in the study of Comet Hale-Bopp // Earth, Moon, and Planets. - 1997. - T. 79, issue. 1-3. - pp. 307-308.
7. Cronk, Gary W. Comet C/1995 O1 (Hale-Bopp)(English) . cometography.com. Retrieved November 10, 2008. Archived from the original on August 20, 2011.
8. Browne, Malcolm R. Comet Holds Clues to Birth of Time, The New York Times (March 9, 1997). Retrieved November 8, 2008.
9. Seiichi Yoshida. Light curve of comet C/1995 O1 (Hale-Bopp)(English) (December 20, 2007). Retrieved November 10, 2008. Archived from the original on August 20, 2011.
10. McGee, H.W.; Poitevin, P. Total solar eclipse March 9, 1997 = The total solar eclipse of 1997 March 9 // Journal of the British Astronomical Association. - 1997. - T. 107, issue. 3 . - S. 112-113.
11. HORIZONS ephemeris generator(English) . JPL. Retrieved November 10, 2008. Archived from the original on August 20, 2011.
12. The Trail of Hale-Bopp(English) . Scientific American (March 31, 1997). Retrieved November 8, 2008. Archived from the original on August 20, 2011.
13. Szabo, Gy. M.; Kiss, L. L.; Sarneczky, K. Comet activity at a distance of 25.7 AU. e.: Comet Hale-Bopp 11 years after perihelion = Cometary Activity at 25.7 AU: Hale-Bopp 11 Years after Perihelion // The Astrophysical Journal. - 2008. - T. 677, no. 2. - C. L121-L124. - DOI: 10.1086/588095 . - arXiv:0803.1505 .
14. Gnedin Yu. N. Astronomical observations of the comet of the century. - Decree. ed.
15. West, Richard M. Comet Hale-Bopp(English) (unavailable link). European Southern Observatory (February 7, 1997). Retrieved November 8, 2008. Archived from the original on August 20, 2011.
16. Bailey, M. E.; Emel'yanenko, V.V.; Hahn, G.; et al. Orbital evolution of Comet 1995 O1 Hale-Bopp // Monthly Notices of the Royal Astronomical Society. - 1996. - T. 281, issue. 3 . - S. 916-924.
17. Yeomans, Don. Comet Hale-Bopp Orbit and Ephemeris Information(English) . NASA /JPL(April 10, 1997). Retrieved November 8, 2008. Archived from the original on August 20, 2011.
18. Cremonese, G.; Boehnhardt, H.; Crovisier J.; et al. Neutral Sodium from Comet Hale-Bopp: A Third Type of Tail // The Astrophysical Journal Letters. - 1997. - T. 490. - C. L199-L202. - DOI : 10.1086/311040
19. Meier, Roland; Owen, Tobias C. Cometary Deuterium // Space Science Reviews. - 1999. - T. 90, no. 1-2. - pp. 33-43. - DOI: 10.1023/A:1005269208310
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