Comet Leonard makes a spectacular pairing with the intense globular cluster M3 within the constellation Canes Venatici on December 3, 2021. Martin Mobberley
Go out the following clear night time otherwise you would possibly miss it! Northern Hemisphere skywatchers have a restricted window through which to view Comet Leonard (C/2021 A1), which can probably grow to be the brightest comet of the 12 months. The excellent news is that whereas time is brief, Leonard is anticipated to achieve peak brightness through the subsequent two weeks. Currently a binocular object round magnitude 7, the comet might grow to be as shiny as fifth magnitude because it travels eastward throughout Boötes, Serpens, and Ophiuchus within the predawn sky.
Comet Leonard’s orbit takes it out to the Oort Cloud, a roughly spherical repository of billions of comets that orbits the Sun out to just about 1 / 4 the gap to the Alpha Centauri star system. Leonard has traveled about 3,500 a.u. for a short spin across the internal photo voltaic system earlier than returning to this frozen fastness. Its place is proven for December 12th, when it comes closest to the Earth. NASA, JPL Horizons
Senior analysis specialist Greg Leonard at the Mt. Lemmon Observatory close to Tucson, Arizona, found the comet on January 3, 2021, when it was little greater than a faint, distant speck. Since then, it is inched steadily nearer to each the Sun and Earth and can attain perihelion — closest method to the Sun — on January 3, 2022. Three weeks prior, on December 12th, it would go nearest the Earth at a distance of 21.7 million miles (34.9 million km).
While Comet Leonard will not examine to the splendor of final July’s Comet NEOWISE, it is more likely to grow to be faintly seen with the unaided eye from a darkish sky inside a couple of days of December 12th. That additionally occurs to be the the date, give or take, that it’s going to succumb to the glare of morning twilight low within the jap sky. You’ll see it greatest with a pair of binoculars or a telescope from areas with a darkish jap sky. Use this mild air pollution map that will help you find the very best spot in your metropolis or area. Fortunately, the Moon will likely be round new part and never a priority.
Comet Leonard crosses by means of Boötes and Serpens within the upcoming week. Stars are proven to about magnitude 6. Stellarium with additions by Bob King
What will we see? Comets might be tough to foretell as a result of they’ve a penchant for unpredictability. Composed of fragile honeycombs of ices each unique and acquainted, they often break aside when nearing the Sun. Solar heating vaporizes the ice, creating pressures inside and with out the comet’s physique that may generally disrupt it, tearing it aside.
It’s even attainable that one thing of the type is occurring proper now with Leonard — after steadily brightening, it has not too long ago proven indicators of plateauing. Assuming its nucleus hangs collectively, binoculars ought to reveal the coma as a tender patch of sunshine, brighter towards the middle, about half the Moon’s obvious diameter. With averted imaginative and prescient it’s possible you’ll glimpse a level or extra of faint tail pointing upward to the northwest.
Keep an in depth eye on Leonard on as many mornings as attainable. Should the nucleus break aside on account of photo voltaic heating or different forces, it might expertise a modest outburst after which fade quickly. Contrariwise, ahead scattering from cometary mud, as mentioned on this earlier article, might quickly pump up its brightness and assure a naked-eye view. We wait with bated lens and telescopes to see what Leonard’s subsequent transfer will likely be.
Comet Leonard races throughout Serpens and into Ophiuchus throughout its final mornings of visibility earlier than transitioning into night twilight. Stellarium with additions by Bob King
As the comet is now shortly approaching each the Earth and the Sun, it is rushing quicker throughout the sky. For the following few mornings (by means of December eighth) you may discover it within the constellation Boötes, not removed from the good, orange large Arcturus. Hold this star’s hand, and you will have an in a position information to Leonard. On Saturday morning, December 4th, the comet stands 8.5° to the star’s higher left and simply 5° away on the sixth. Although the comet’s altitude decreases every morning, this can be offset by its rising brightness. Peak magnitude round 4.5–5 is anticipated from about December 10th to December 15th.
Staring on round December 12th, Leonard swings into the night sky and slowly distances itself from the Sun whereas additionally fading. This is when Southern Hemisphere observers may have the very best view, whereas nightfall will probably swallow the sight for northerners. I made my final Leonard commentary in 10×50 binoculars and a 15-inch telescope through the November lunar eclipse. With the moon tucked deeply in shadow at mid-eclipse, I stole views of its fluffy coma, compact “fuzzy-star” nuclear area and beautiful degree-long tail.
As I write this, I’m on a cruise ship rushing northeast at 15 knots an hour towards the centerline of the December 4th complete photo voltaic eclipse. With luck, we’ll arrive below clear skies close to South Georgia Island off the coast of South America and, if profitable, I hope to share photographs of the singular occasion tomorrow proper right here.
I point out my location and objective as a result of from latitude -60° south Comet Leonard is burrowed deep beneath my horizon. And by the point I return residence will probably be misplaced in twilight glare. I encourage all of you lucky sufficient to be in the best place to reap the benefits of your viewing alternatives. Find a darkish location and search this dusty phantom that has lastly arrived at your door after a 35,000-year pilgrimage from the outer photo voltaic system. Oh and please say “hi!” for me.