An overview of what’s happening
On January 3, 2021, a 19th magnitude speck was discovered by G Senior research specialist Greg Leonard at Mt. Lemmon Observatory found a faint speck. The 19th magnitude speck was an incoming comet, now called Comet C/2021 A1 (or simply comet Leonard). At its discovery, comet Leonard was about 750 million km away from us.
In the first week of December, its brightness increased to an apparent magnitude of +6.3. Apparent magnitude is a scale used by astronomers to describe a celestial object’s brightness. The smaller the number, the brighter the object. Unaided human eyes can see up to a magnitude of +6 under perfectly dark skies. Hence, comet Leonard was an excellent binocular/telescope object in the pre-dawn sky. On December 12, the comet made its closest approach to the Earth as it passed within 34.9 million km of the planet.
After that, comet Leonard flipped from a morning object to an evening one. It is approaching the Sun and will reach its perihelion (closest to the Sun) on January 3, 2022, exactly a year after its discovery. The comet will then continue its hyperbolic trajectory and exit the solar system, never to return.
Last chance to see comet Leonard
In 2020, we got to see the ‘Christmas Star’ as Jupiter and Saturn paired up in the southwest at dusk during the Great Conjunction. This year, we have a ‘Christmas Comet’ in the same region of the sky around the same time of the day.
Comet Leonard will appear in the southwest at dusk throughout the year but look for it sooner rather than later as it will become dimmer and dimmer heading into the final days of this month.
December 18 is an exciting day to see the comet as it will be pretty close to Venus, as shown above. Venus is the brightest speck of light in the dusk sky in the southwest direction, followed by Jupiter. If you have access to crystal-clear horizons and dark skies away from city lights, you might be able to see the comet with naked eyes. Otherwise, a small pair of binoculars (7×35 or 10×50) or a small telescope (60 mm) would be great. The best viewing time would be 45-60 minutes after the Sunset. These space apps can provide you with the comet’s exact location according to your place.
Brightness of C/2021 A1 (Leonard) from today's image of Igor Chilingarian: m1=2.6 ± 0.3 V; the comet is much brighter than expected.— Artyom Novichonok (@illvmvm) December 15, 2021
Very possible, outburst has occured and we see small, quite condensed round coma of "young" dust enhanced forward-scattering effect. pic.twitter.com/RRCUdNS5qW
Some sky-gazers are reporting that the comet’s brightness is rapidly increasing which means, it might decorate the evening skies this week. However, A1 Leonard will not be as prominent as comet NEOWISE seen last year.
Comet Leonard photos
Astronomy Calendar 2022
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