Dr S A MOHAN KRISHNA

Mysuru: IT IS A VISUAL TREAT FOR THE SKYGAZERS AS A HEAVENLY VISITOR COMET “LEONARD” COMES BY THIS MONTH.

The brightest comet of the year will put up a great show in the sky of December. It shall be once in a lifetime experience as this comet won’t be seen ever again. This comet is traveling at an impressive speed of 254,000km/h. This can be seen to the naked eye and shall be the best comet of this year.

It can be seen in the morning sky during the first week on December and later after December 14, it will be perceptible in the evening sky, very close to Venus. Green Comet Leonard is about to pass close to Earth, which is the first time in 70,000 to 80,000 years. In the Northern Hemisphere, it can be seen in the east with the aid of small telescopes and binoculars.

The most beautiful and impulsive celestial object perceptible in the night or morning sky is the ‘Comet’. Most of the time, comets remain in deep-frozen “sleep” in outer space, but sporadically they are dislodged from their orbits and fall forward the inner solar system. Comets are at their brightest when they are closest to the Sun, it is best to search for them in the sky unswervingly after sunset although never when the Sun is still above the horizon.

In the months of December of this year and January of next year, fix your stares on the sky to watch the spasmodic comet ‘Leonard’. Throughout December and January, it will be discernible in the Northern Hemisphere.

The behavior of the comets is highly unpredictable. Comets large enough to be detected in the outer solar system may prove to have thick, insulating crusts that they never develop, whereas smaller comets may be as insubstantial as a snowball and melt away to fragments as they come closer to the Sun.

A much-anticipated comet – C/2021 A1 (Leonard) – is probably to be 2021’s best comet, and its liveliest comet by year’s end. The comet is currently heading sunward, toward its perihelion (closest point to the sun) on January 3, 2022. Comets are typically brightest around perihelion. Comet Leonard has been in the morning sky, and it just passed the beautiful globular star cluster M3. 

Senior research specialist Gregory Jacques Leonard at the Mount Lemmon Observatory near Tucson, Arizona, discovered the comet on January 3, 2021, when it was little more than a faint, distant speck. Since then, it’s inched steadily closer to both the Sun and Earth and will reach perihelion — closest approach to the Sun — on January 3, 2022. Three weeks prior, on December 12th, it will pass nearest the Earth at a distance of 21.7 million miles (34.9 million km).

Over the coming month, as Comet Leonard heads sunward, it’ll sweep closest to Earth on December 12. It won’t be particularly close at its closest, passing more than 21 million miles (34 million km) away. But six days later – on December 18 – the comet will have an exceptionally close pass of Venus of just 2.6 million miles (4.2 million km). Then it’ll round the sun on January 3, 2022, at a distance of about 56 million miles (0.6 AU, or 90 million km). Also, this month one can see to three celebrated planets, Venus, Jupiter and Saturn in line and meteor shower, Geminids will light up the night sky. 

A striking feature of this celestial visitor is that it’s an ultrafast comet. It’s traveling at 158,084 miles per hour (254,412 km/h or 70.67 km/second) relative to Earth. Despite its incredible speed through the vast space of our solar system, don’t expect to see this comet swoosh across the sky. Like planets, comets do move in front of the star background, but only very slowly due to the large distances involved. Is it possible to observe this comet’s motion. Despite its high speed, you’ll find that its distance from Earth – and the vast distances in our solar system – will cause the comet to appear as a very slow-moving object. Professional observatories rarely has time to devout to scan skies in search of new celestial objects, so amateur astronomers using simple equipment often discover comets. Presently, ‘Leonard’ can be seen in northeast direction directing towards ‘Bootes’ constellation at a visual magnitude of 5 and has been getting brighter and larger since first week in December.

This comet is presently undoubtedly a morning comet during the first week of December and is clearly discernable in the evening sky very close to Venus with a visual magnitude of 4 or 5, even from even small telescopes after December 14 after sunset, provided the evening sky should be absolutely clear. Note that, lesser the value of magnitude, greater the brightness.

This comet can be located near planet Venus in the morning sky presently. Initially, Leonard was not expected to get much brighter than seventh or sixth magnitude, making it manageable only to those with good binoculars or small telescopes. A compromise of observations placed it at magnitude 8 on November 10 of this year.  

Astronomers say it may be possible to witness this bright green iceberg after sunset sometime in the evening later in the month. Comet Leonard will be closest to Earth on December 12, 2021. The good news is that – if the comet continues looking great – the view the night of closest approach should be nice. On the morning of 6 December 2021, the comet will be about 5 degrees from the star Arcturus.

On 14 December 2021 the comet will be 14.7 degrees from the Sun and will quickly become better seen from the southern hemisphere. The forward scattering of light could cause the comet to brighten to as much as magnitude ~2. Although small binoculars and telescopes might be required for the celestial visitor, it will be noticeable at the same time we see a beautiful crescent (not too bright) moon. Even with the help of small telescopes and binoculars, the comet is noticeable. The comet is visible from all parts of India. Comet Leonard was seen almost 70,000 to 80,000 years ago and may not be discernable after this.

The various astronomical devices used to witness this particular comet are Celstron Nexstar11 telescope, Meade F3.3 focal reducer, and Stellacam II video camera and Canon 6D, 200 mm Lens f6.3, SO 800. The morning sky is somehow clear from moon light and is the advisable time to see this comet in by revealing the magnanimity and elegance of sky watching. The reflecting telescope with 6-inch reflector will do to witness this comet. So enjoy watching ‘Leonard’ and reveal the magnificence of astronomy.

( The writer is amateur astronomer, Convener, Mysore Astronomical Society)

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