Comet Leonard (C / 2021 A1): Hope for a comet that can be seen with the naked eye

Does the spotlight on astronomy come in winter? Comet Leonard (C/2021 A1) may soon be visible to the naked eye. What you want to know about the note.

Update from Tuesday, November 30, 2021 at 4.15pm: Comet Leonard (C/2021 A1) is currently closer to the Sun than ever before; On January 3, 2022 it reached perihelion, which is the closest distance from the Sun. Before that, you should be more visible in the sky. It currently has a magnitude of 7, so it can be observed with binoculars or a small telescope when the sky is clear. The comet is currently located in the constellation “Haar der Berenike” and is on its way toward the constellations “Hunting Dogs”, “Bear Guardians”, “Snake” and “Snake Bearers”. On December 12, it reached its closest location on Earth – about 34.4 million km away.

How the comet develops in the near future will determine whether it is visible to the naked eye in the sky. Recently it has developed well, its brightness has increased by several amounts. In the photos, you can see that it has a green heart and fluffy tail. Experts assume that Comet Leonard can reach a magnitude of 4 – then it will be visible in the sky with the naked eye.

Update from Friday, November 26, 2021 at 8.40pm: Comet Leonard (C/2021 A1) continues to rotate across the night sky and is becoming noticeably brighter compared to the beginning of November. Observers now estimate it to be between 7 and 8 in size – that is, it can be seen in the sky with binoculars or a small telescope. Comet Leonard is currently located in the region of the constellation “Haar der Berenike” and the galaxy NGC4656 and is moving in the direction of the constellation “Bear Guardian”. On December 6, Comet Leonard is close to the prominent star Arctur, so it’s easy to find.

If you want to observe Comet Leonard, you have to be prepared to stay up long or to get up early: Comet only rises in the northwest around midnight and rises into the sky during the night. Even if some call Comet Leonard a “Christmas Comet,” that name is misleading: the comet will reach its closest point to the sun on December 12 (the so-called perihelion) and will then be very low in the sky when observed from the northern hemisphere. The best observation period is actually before December 12, 2021.

Comet Leonard: Not a ‘Christmas Comet’, but it’s probably a celestial sight

First report on Sunday, November 7, 2021 at 8:22 pm: Frankfurt – a comet that can be seen in the sky with the naked eye does not happen very often. In recent years, only one comet has fallen midway into this category: Comet Neues (C/2020 F3) was visible to the naked eye for some time in the summer of 2020 and under very dark skies. But there may soon be a successor: Comet Leonard (C/2021 A1) Currently astronomers are watching it closely – it will likely become bright enough. But you should not rejoice early – 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 spotted on January 3, 2021 by astronomer Greg J. Leonard at the Mount Lemon Observatory in Tucson, Arizona. At that time, the comet was about 750 million kilometers from the Sun. On January 3, 2022, its path will be closest to the Sun, known as perihelion.

Then Leonard is about 92.2 million km from the Sun. It already had the closest approach to Earth before that: NASA estimates that Comet Leonard will approach Earth on December 12, 2021 at about 2:54 p.m. German time — at a safe distance of about 35 million km.

Comet Leonard (C / 2021 A1) can be seen with the naked eye in November / December 2021

The brightness of Comet Leonard will appear in November and December 2021 with the passage of time. According to estimates by the “EarthSky” portal, the brightness is assumed to be between 5 and 2.6. The lower this value, the brighter the object can be seen.

But comets’ behavior is generally considered unpredictable, which makes it very difficult to predict how Leonard’s comet’s brightness will evolve. For example, Comet Atlas was considered the bearer of hope in 2020 – and it broke before it could make a show in the sky. Something similar happened to Comet ISON in 2013, which crashed on its closest approach to the sun.

How to find Comet Leonard in the night sky

If Comet Leonard becomes visible to the naked eye, it will be seen first in the Northern Hemisphere, and then later in the Southern Hemisphere. The comet is traveling at 254,412 kilometers per hour – but you won’t see it “racing” across the sky, because Leonard is so far from Earth.

One thing is for sure: if you want to see a comet in the sky, you have to look for it early in the morning. Around mid-November, Comet Leonard wandered into the constellation “Haar der Berenike,” which rises about 1.30 east. On December 2, the comet can be seen near the globular cluster M3, and then moves toward the bright star Arctur in the constellation “Bear Guardian”.

Comet Leonard can be seen with telescopes as early as mid-November

Specialized magazine “Sky & Telescope” estimates that the comet can reach its magnitude 10 in mid-November – a brightness that cannot be seen with the naked eye, but can already be seen with smaller telescopes. By the time Comet Leonard approaches the star Arcturus, it can have a magnitude of 5.5, thus becoming something faintly perceptible to the naked eye.

In the Northern Hemisphere, you can peek at the comet in the morning sky on December 12, 2021 — shortly before its theoretical maximum brightness. It will then be visible in the depths of the southwestern sky at dusk. Observers in the Southern Hemisphere now have the opportunity to look at the comet.

Comets are “dirty snowballs” from the depths of space

Comets come from the depths of space and are made up of dust and rocks that are held together by ice. When a comet approaches the Sun, the ice melts and dust and stones are liberated – the comet’s characteristic tail forms. This is exactly what makes predicting the brightness of Leonard’s Comet (C / 2021 A1) so difficult: no one can predict exactly how the comet will behave in the increasing heat – it will become more energetic, but how active? No one can reliably expect that at the moment.

Comets – nickname: “cosmic snowballs” – are of particular interest to research because they are considered messengers from the depths of the universe. According to NASA’s calculations, Comet Leonard came from the outer solar system and moved more than 550 billion km towards the center of the solar system 40,000 years ago. After reaching perihelion, according to NASA, it will likely be expelled from the solar system. So winter 2021/22 is your last chance to see Comet Leonard.

Only recently, two researchers accidentally discovered the largest comet known to date. It is on its way towards the center of the solar system, in the year 2031 it should reach its point closest to the sun. (Tania Banner)