A new wave of comets are coming together, set your alarm clock soon
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< p>Green fluffy and diffuse comet Atlas (C/2020 M3)
It has a very bright pseudonucleus
With the departure of the summertime-Comet Xinzhi (C/2020 F3), the night sky in the northern hemisphere quickly fell silent, and there are few comets that are easy to observe. However, in the next few weeks, there will be a large wave of”new faces” coming to light up the night sky again! Among them, four comets can be observed using amateur telescopes. They are the period Comet Russell-Linear (156P/Russell-LINEAR) visible at night, and Atla, visible at dawn. Comet(C/2020 M3), Comet Erasmus(Erasmus, C/2020 S3) and another Comet Xinzhi(C /2020 P1).
Comet Atlas (C/2020 M3) this month will gradually climb north from Lepus to Orion , the brightness will increase to 8. The figure above shows the position of Comet Atlas (C/2020 M3) from October 22nd to November 19th at 0:00 UTC (8:00 Beijing time) daily.
Source:Sky & Telescope
Let’s start with the brightest of the”four brothers” Atlas Comet (C/2020 M3) Speaking of it, it was discovered by the Asteroid Terrestrial-Impact Last Alert System (ATLAS) operated by the University of Hawaii on June 27, 2020. At that time, the brightness was only 19 grades, but now it is 8.5. Wait, is accelerating from Lepus to Orion.
At midnight, Atlas rises in the sky and arrives at the highest point in the south at 4 am, the best observation time. On October 16th, I used my 15-inch Dobson telescope to observe in the suburbs, and I was quickly shocked by its huge fluffy appearance-it was like a large ball of cotton candy!
This picture shows the degree of coma condensation from 0 (none) to 9 (close to the star)
Picture source:Bob King
I estimate The apparent diameter of the coma is 11′, and the degree of condensation is 3 (the degree of condensation ranges from 0 to 9, which means that the coma has a completely diffuse appearance to a star or disc appearance). The magnification is increased to 245 times, and a star-like point can be found in the center, the so-called false nucleus or pseudonucleus. The real comet nucleus is very small, well hidden in the dust released by itself. Although the overall brightness of the comet is relatively bright, its diffuse shape and huge diameter make it look much darker than you think—especially where there is light pollution. Recently, however, several people have observed it with binoculars, including one of the discoverers of Hale-Bopp comet from New Mexico-Alan Hale, He used his 10×50 binoculars to make observations on October 15.
Atlas’s coma and its stubby tail, captured by Gerald Rhemann on October 16th, facing northeast
< p>Source:Gerald Rhemann
When I observed, I used a Swan band filter, which can filter the light of other colors and preserve the green light, which is very good for the rich green C2 1 The gas Atlas comet (C/2020 M3) can significantly increase its contrast with the black sky and improve visibility. Throughout the first ten days of December, the brightness of Atlas will remain stable at 8th magnitude, steadily climbing northward from Lepus, passing through Orion and reaching Auriga. The best observation time is before October 29 or November 7 to 29.
Atlas passed the perihelion on October 25, 1.27 astronomical units (190 million kilometers) from the sun, and reached perigee on November 14, 53.6 million kilometers from the earth. On October 27, Atlas passed Pingyi (μ Lepus) at a distance of less than ½°, and reached 1° east of Betelgeuse (β Orion) on November 4.
The South African Astronomical Observatory (SAAO) produced this moving picture before and after the discovery of Comet Erasmus (C/2020 S3)
If you have successfully observed Atlas, then congratulations, then you can turn the direction of the telescope and try to find Erasmus comet east of Hydra ( Erasmus, C/2020 S3). Nicolas Erasmus (Nicolas Erasmus) is an astronomer at the South African Observatory. He first discovered this comet with an apparent magnitude of 18.5 on September 20 this year. The brightness of the comet changes rapidly. The current brightness is about 11th magnitude, and the brightness will reach 7-8th magnitude at the end of November, and it will pass the perihelion (0.4 astronomical unit from the sun) on December 13.
Currently Erasmus (C/2020 S3) is located between Hydra and Sextant before the dawn, but its distance is Decrease rapidly, especially at the end of next month. At the beginning of dawn, its height is only one punch higher than the Virgo in the southern sky. It will be no small challenge to observe again. However, it is hoped that the increasing brightness can offset some of the influence of the height reduction on the observation. At the beginning of December, it will completely disappear in the radiance of the sun.
This is the comet Erasmus (C/2020 S3) taken on October 11. It is very dim. Its brightness will increase to about 7-8 in late November, and it will reach perigee on November 8, 1.04 AU from the earth.
On October 16, I easily observed Erasmus (C/2020 S3) with a low-power telescope (64×) , It emits a soft milky white light with a brightness of 11.5 magnitude, a condensation degree of 3 degrees, and a coma diameter of 3′. Just like observing Atlas, this Swan Band filter is indispensable.
In the next month, Erasmus (C/2020 S3) will fly to the vicinity of the Milky Way and will have the opportunity to be in the same frame as the deep sky objects. Perhaps the most interesting frame occurred on November 17, when it will approach the bright NGC 4361 planetary nebula in Corvus from the north at a close range of ½°. At the end of the year, it will quickly escape in the dark night sky.
Comet Xinzhi (C/2020 P1) taken on September 28, 2020
These few days Comet Xinzhi (C/2020 P1) has appeared in the sky, just after the perihelion on October 20, only 0.34 AU from the sun. Although Comet Xinzhi (C/2020 P1) is a small comet, if it can survive the perihelion, its brightness should reach magnitude 8 of the apparent magnitude.
Because of its small distance, you need an ideal observation site with a good view, facing the east-northeast-Virgo direction, bring an alarm clock to set the time, catch the dawn before the sun rises From 90 minutes to 2 hours, try to find it, and soon it will disappear in the Shepherd’s Seat in the north.
Let’s look up at the starry sky again and look for the last comet to the south of Aquarius-Comet Russell Linnell (156P/Russell-LINEAR), which continues to the northeast Climb, reach Pisces on November 15 and continue until the end of the year.
I made an observation on October 12, it is located in Yufu constellation, brightness is 13th magnitude, the degree of condensation is very good, reaching 5 degrees, and the central coma is only 0.5′ in diameter. After careful searching, I found a faint coma in the outer layer, which increased its apparent diameter to 1.5′. Other observers also noticed this remarkable two-layer coma-a dense and bright inner coma surrounded by a larger (up to 5′), low-luminance outer coma.
Comet Russell Linnell (156P/Russell-LINEAR) will reach 12th magnitude in early November and then slowly dim. If you have an 8-inch or larger telescope, you can try it out in the dark sky. The comet moved steadily northward during its orbit, and visibility increased.
Comet Russell Linnell (156P/Russell-LINEAR) has a large diffuse coma, enveloping its pocket nucleus
Because Comet Russell Linnell was close to its maximum brightness before perihelion on November 17, astronomers speculated that it might be breaking apart. The photo taken on October 12 by Michael Mattiazzo revealed that the comet has a pseudonucleus deviating from the center of the coma, which can be used as one of the evidences that Comet Russell Linnell has ruptured. A similar phenomenon is related to the ruptured Schwartzman-Watt Comet Hermann 29 (29P/Schwassmann-Wachmann) often appears in observations.
Comet Russell Linnell (156P/Russell-LINEAR) was first discovered by KS Russell on September 3, 1986 at the Saidin Spring Observatory in Australia, and then in 1993 and 2000 It was discovered twice again, at first it was considered an asteroid, and later confirmed to be a one-cycle comet.
Like falling leaves flying in the autumn wind, comets set sail again in the autumn night sky! Let’s bring the equipment and try to find them, one, two, three, four…
Note 1:C2, diatomic carbon, Green gaseous element, chemically unstable. It is a form of diatomic molecule of carbon element at high temperature. It can be prepared by electric arc (generating C60 at the same time). It can be found in comets, stellar atmospheres and interstellar matter And blue hydrocarbon flames also exist.
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Responsible editor:Ma Yue
Mufu New Media Editorial Department
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