Comet new wisdom returns once in 6000 years

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 Comet new wisdom returns once in 6000 years


At the time of its first discovery, it was at the base of the ship. It passed through Canis Major and Uranus in mid and late April, passed through kylin and Orion at the end of May, and moved from south of the ecliptic to north of the ecliptic at the end of June. In July, it passes through Auriga, tmall and Ursa Major. In August, it enters the spring sky, and comes into the constellation Altair, shepherd, and Virgo. After that, as we get farther and farther away from us, the brightness will get darker and darker, and it will not return until more than 6000 years later.

Little transparency suddenly shines in the night sky

On March 27, 2020, the wide area Infrared Sky Survey Explorer Space Telescope discovered the object during its neowise mission. At that time, its brightness was only about 18 degrees, about 300 million kilometers away from the sun and 250 million kilometers away from the earth. In April 2020, the comet was named after the project name neowise, and the comet number was C / 2020f3, where C represents that it is a long-term or aperiodic comet, and 2020f3 means that it is the third comet discovered in the second half of March 2020.

Todays famous comet Xinzhi was actually a little transparent when it was first discovered. As it gets closer to the sun, comet Xinzhi is getting brighter and brighter. In the first ten days of June, it is close to the sixth grade. But as it moved to the back of the sun, the comet disappeared from view. It was not until half a month later that comet Xinzhi appeared again, and its brightness had reached 2.5.

In a short period of more than half a month, comet Xinzhi was invisible to the naked eye, and its brightness increased by about 100 times. Why does the brightness of the same comet change so much? In fact, the main reason is the distance between the comet and the sun.

The reason why comets can be seen is that they reflect sunlight. On the one hand, as the comet approaches the sun, the intensity of sunlight increases, so it looks brighter and brighter. On July 3, 2020, comet Xinzhi will reach perihelion, only about 43 million kilometers away from the sun.

On the other hand, the comets speed is increasing, resulting in the dust tail pulling longer. So the closer a comet is to the sun, the brighter it looks. The energy of the sun heats the comet, and gas and dust erupt from the comets surface, forming a huge dust tail, which is generally yellow. At the same time, the comet will produce a stream of charged particles under the action of the solar wind, forming an ion comet tail, which is generally blue.

It can provide clues for the birth of the solar system

Besides appreciating comets, scientists can also obtain important scientific information from them.

Astronomical observation is generally divided into two types, one is imaging photometry, the other is to obtain spectral data, so is comet observation. For astronomers, when a comet is very far away from the sun, it is difficult to directly determine whether it is a comet, which requires a large aperture Sky Survey Telescope with high sensitivity terminal equipment to obtain more information.

Comets formed outside the snow line of the early solar system. It carries a lot of original information about the solar system, such as the hydrogen isotope abundance mentioned above, which is likely to be different at different locations in the early solar system. Although the shape, mass and orbit of different comets are quite different, they have a common feature: they all contain ice. The water on the earth is likely to come from the early comet collisions. By comparing the hydrogen isotope abundance of the water on earth with the data of different comets, combined with the orbits of various comets, scientists can constrain the early evolution model of the solar system.

How can the public grasp this excellent opportunity to observe comet Xinzhi once every 6000 years?

Comet Xinzhi is very bright and suitable for observation in the northern hemisphere in recent years. It can be observed or photographed in the city on a good night. In the middle and late July, the brightness of comet Xinzhi dropped to below grade 3. If you want to enjoy this comet, you need to consider the following questions.

Weather is particularly important for astronomical observation. Eastern China is located in the monsoon climate zone. July is the season with the most rainfall. You can use the astronomical Weather software to query the weather and plan the observation time in advance. Of course, if there are conditions, it is recommended to select areas with high probability of sunny days for observation.

In addition, the highest altitude of comet Xinzhi is about 20 degrees after sunset, and then it will slowly decrease. Therefore, the northwest of the observation area is relatively open. In the city, you can choose to observe in the park or higher floors. In the area where the comet can be seen all night, it is relatively open from northwest to northeast, especially due north.

(function(){( window.slotbydup=window .slotbydup||[]).push({id:u5811557,container:ssp_ 5811557, async:true }The beauty of a comet lies in its tail, but even in places where the observation conditions are relatively good, it is difficult to see the comet tail directly with the naked eye, and some equipment is needed to assist observation, such as binoculars. Its portable and affordable. It is recommended that you use 7x50 mm or 10x50 mm binoculars (the number in front of X is the multiple, and the number behind x is the aperture). The price ranges from 500 yuan to 1000 yuan. In addition, it is recommended to purchase a special bracket for binoculars, so that the binoculars can be installed on a tripod to enjoy the comet slowly and avoid overwork on both hands. The most difficult point in observing comet Xinzhi with binoculars is how to aim the comet. We can use the electronic star map to determine the position of the comet in advance, and then use the star bridge method or the surrounding bright stars to locate it. For example, at 21:00 on July 21, 2020, the location of comet Xinzhi is just below Tianxuan, the Big Dipper star. You can use binoculars to find Tianxuan first, and then look down vertically. It is easy to find the comet. (author: Su Chen, unit: Beijing Planetarium) source: Science and technology daily, editor in charge: Li Chong_ NN5538

The beauty of a comet lies in its tail. However, even in places where the observation conditions are relatively good, it is difficult to see the comet tail directly with the naked eye. Some equipment is needed to assist observation, such as binoculars. Its portable and affordable. It is recommended that you use 7x50 mm or 10x50 mm binoculars (the number in front of X is the multiple, and the number behind x is the aperture). The price ranges from 500 yuan to 1000 yuan. In addition, it is recommended to purchase a special bracket for binoculars, so that the binoculars can be installed on a tripod to enjoy the comet slowly and avoid overwork on both hands.

The most difficult point in observing comet Xinzhi with binoculars is how to aim the comet. We can use the electronic star map to determine the position of the comet in advance, and then use the star bridge method or the surrounding bright stars to locate it. For example, at 21:00 on July 21, 2020, the location of comet Xinzhi is just below Tianxuan, the Big Dipper star. You can use binoculars to find Tianxuan first, and then look down vertically. It is easy to find the comet.

(author: Su Chen, unit: Beijing Planetarium)