Start 2019 with the Quadrantid Meteor Shower

By: Bob King January 2, 2019 6

Set aside your qualms about the cold and cash in on the Quadrantids, one of this year's best meteor showers.

Where to see Quadrantid meteors — The Quadrantids got their name from Quadrans Muralis, one of many constellations invented in the 18th and 19th centuries that never quite caught on. This is the view for about 1 a.m. local time, when the shower's radiant reaches a reasonable height above the horizon.

Let's make it two in a row! Conditions were excellent for last month's Geminid meteor shower and will be again for the upcoming Quadrantids. This annual shower is something of a black sheep among meteor watchers with its brief peak, frigid viewing conditions, and odd origin. While active from late December to mid-January, most of the the shower's material is concentrated in a thin band which Earth passes through perpendicularly, the reason for its short duration. We're in and out in a little more than 6 hours.

But if maximum happens when the radiant stands high for your location, get ready for excitement. Sightings of 100 "Quads" an hour aren't uncommon, a not too rare prize. I've only seen one maximum, back in the 1980s. It was a bitter cold morning, but meteors popped out all over, making it one of the best showers I've ever seen.

Bright Quadrantid meteor — It was the only Quadrantid meteor captured by Maryland skywatcher Mike Hankey during 10 hours of photography, but it's a doozy. The bucket of the Big Dipper appears at upper right. Shower members strike the atmosphere at "medium" speeds of around 40 kilometers per second.

According to Robert Lunsford of the American Meteor Society the 2019 peak will occur around 2:30 UT on Friday, January 4th, ideal for skywatchers in Europe, North Africa, and far western Asia. For other parts of the world, we can expect about 25 meteors per hour, still a good showing. No Moon will damage the meteoric goods as it's a super-thin crescent that won't show up till dawn. Speaking of which, if you get up before dawn to take in the meteor shower, stick around. You might just get to see the 672-hour-old Moon (1.5 days before new) 45 minutes before sunrise about 5° high in the southeastern sky, 15° to the lower left of Jupiter. If your eastern horizon allows, look for –0.4-magnitude Mercury glimmering about 2½° below the Moon. Bring binoculars for assistance.

The Quadrantids are a Northern-Hemisphere-only experience, as the radiant lies below the handle of the Big Dipper in Boötes at declination +49°. Northward of +40.5° latitude, the radiant is circumpolar, so it never actually dips below the horizon. As the stars pivot about Polaris, the radiant scrapes along the northern horizon for hours. While a low radiant will absolutely reduce meteor sightings, it may also afford us the opportunity to see at least a little of the shower at its peak across North America.

Cold comfort — The author relaxes on a lawn chair under a sleeping bag while anticipating the next meteor during last month's Geminid shower. Bundled against the cold or dew, meteor-watching is one of astronomy’s most relaxing and rewarding activities.
*Bob King*

2:30 UT translates to 9:30 p.m. Eastern Standard Time (8:30 Central; 7:30 Mountain, and 6:30 Pacific). If nothing else, skywatchers on Thursday evening (January 3rd) can watch for Quadrantid Earthgrazers by facing the northern sky during the evening hours. Earthgrazers are slow-moving meteors that launch upward from the horizon and flare for a long time before fading out. If you live in the wilds of northern Canada, north of about latitude 60° north, the radiant will stand at least 20° high in the northern sky even at nadir, making it easy to catch the peak that evening.

For those outside the narrow peak zone, you can observe the shower in stages, checking for Earthgrazers during the evening and then rising an hour or two before the start of dawn — between 4 to 6 a.m. local time — when the radiant stands highest in the northeastern sky. As always, there's no preferred direction in which to look, but avoid staring at the radiant, where meteors approach head on and sketch only short streaks. Facing about 90° away from the radiant provides a mix of short and longer, more dramatic trails.

Earth takes aim — Notice how steeply the orbit of 2003 EH₁ and its meteor spawn are inclined to Earth's orbit. Coming in perpendicularly, Earth literally shoots through the densest stream of meteoroids in hours. Positions and data are shown for Jan. 4.0 UT.
*NASA / JPL Horizons*

Most meteor showers originate from comets, and it appears that the Quadrantids do, too. Meteor expert Peter Jenniskens found an excellent match between the ~2.9 kilometer-wide object 2003 EH₁ and the meteor stream. While it's likely an "extinct" comet because it doesn't exhibit a fuzzy coma, the shower may have been spawned by the break-up of a larger comet into smaller pieces in the not-too-distant past, one of which became 2003 EH₁.

Farewell Wirtanen! — Comet 46P/Wirtanen slows down and fades as it travels from Lynx into Ursa Major the the next couple of weeks. I’ve marked the comet’s position at 5-day intervals. You can interpolate between the marks for other days. Stars are shown to magnitude 6. Start at Capella and use it and other nearby stars like Delta Aurigae, 2 Lyncis and 15 Lyncis to help you point binoculars toward the comet.
*Stellarium with additions by the author*

I mentioned bringing binoculars for the Moon and Mercury, but you can also use them to observe our comet friend 46P/Wirtanen, now crossing from Lynx into Ursa Major. Last month, it was an easy naked-eye object from reasonably dark skies, but it's fading now as its distance from Earth continues to increase. On December 28th, I saw it only marginally without optical aid from a dark site at ~4.8 magnitude, but my 8×40s and 10×50s picked the comet up with ease. Comet 46P/Wirtanen remains well placed from nightfall till dawn. With the Moon returning in less than two weeks, this may be the last time to see the comet in binoculars.

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