Astronomical Highlights: How bright is the comet Leonard in the sky?

Winter Astronomical Highlights: Comet Leonard (C / 2021 A1) visible to the naked eye in November and December. What do you need to know

Frankfurt – The comet that can be seen with the naked eye in the sky does not often occur. Only one comet in recent years falls into this category: Comet Neovis (C / 2020 F3) is visible to the naked eye for some time in the summer of 2020 and in very dark skies. But soon there may be an heir: Comet Leonard (C / 2021 A1) Currently being meticulously observed by astronomers – it has the potential to become bright enough. But you should not be happy too soon – because it is very difficult to assess the behavior of comets.

Comet Leonard was the first comet to be discovered in 2021: it was first discovered on January 3, 2021 by astronomer Greg J at the Mount Lemon Laboratory in Tucson, Arizona. Discovered by Leonard. At the time, the comet was about 750 million kilometers from the Sun. On January 3, 2022, its orbit will be very close to the Sun, known as the Perihelion. Leonard is 92.2 million kilometers from the sun. It already has a very close approach to Earth: NASA, the US space agency, estimates that the comet Leonard will be closest to Earth on December 12, 2021 at 2:54 pm German time – about 35 million kilometers away.

Comet Leonard (C / 2021 A1) visible to the naked eye in November / December 2021

How bright the Leonard comet will be in November and December 2021 will only be known over time. According to the estimates of the “Earthsky” portal, a brightness between size 5 and 2.6 is considered. If this value is low, the object can be viewed brightly. But the behavior of comets is generally considered unpredictable, making it very difficult to predict how the brightness of comet Leonard will develop. For example, the comet Atlas was considered hopeful in 2020 – and it broke before it could perform in the sky. In 2013 something similar happened to the comet Ison, which was distorted in its close approach to the Sun.

How to find the Leonard comet in the night sky

If the Leonard comet is visible to the naked eye, it is visible first in the northern hemisphere and then in the southern hemisphere. The comet travels at a speed of 254,412 kilometers per hour – but because Leonard is so far away from Earth it cannot see the “race” across the sky. One thing is for sure: if you want to see a comet in the sky, you have to notice it early in the morning. In mid-November, the comet Leonard orbits the “Hor der Perenike” galaxy, which rises at 1.30am in the east. On December 2, the comet is seen very close to the global cluster M3, and then moves toward the brightest star in the galaxy, “Bear Guardian”.

The special magazine “Sky & Telescope” estimates that the comet could reach size 10 in mid-November – a brightness still invisible to the naked eye, but already visible through small telescopes. By the time the comet Leonard Arcturus approaches the star, it may have reached a magnitude of 5.5, making it invisible to the naked eye. In the Northern Hemisphere, you can see the last sighting of a comet in the morning sky on December 12, 2021 – just before its theoretically greatest brightness. Then at dusk the low is visible in the southwest sky. Visitors to the Southern Hemisphere also now have the opportunity to see the comet.

Comets “dirty snowballs” from the depths of space

Comets come from the depths of space, and they contain dust and rocks bound together by ice. As a comet approaches the Sun, ice melts, dust and rocks are released – the characteristic comet’s tail is formed. The brightness of the comet Leonard (C / 2021 A1) is very difficult to predict: no one can accurately predict how a comet will react to rising temperatures – it will become very active, but how active? No one can predict it at a reliable time.

Comets – nicknamed: “Cosmic Snowballs” – are very interesting to research because they are considered messengers from the depths of the universe. According to NASA estimates, the comet Leonard comes from the outer solar system and has been moving for more than 550 billion kilometers toward the center of the solar system for 40,000 years. According to NASA, once he reaches his perihelion, he will be ejected from the solar system. So the 2021/2022 winter is the last chance to see the comet Leonard.

Recently, two researchers accidentally discovered the largest comet known to date. It is on its way to the center of the solar system, and by 2031 it should reach its point closest to the sun. (Tab)