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Vega marks radiant point of April’s Lyrid meteor shower

The radiant point for the yearly Lyrid meteor shower is near Vega, brightest star in the constellation Lyra the Harp.

Tonight for April 20, 2014

The 2014 Lyrid meteor shower is now picking up steam, though unfortunately, under the light of the waning gibbous and last quarter moon. This shower is usually a modest one, even when the moon is out of the sky, offering perhaps 10-15 meteors per hour at its peak. The maximum number of Lyrid meteors will probably rain down during the predawn hours on April 22 and 23, yet under a moonlit sky. This year, it may be to your advantage to watch this shower, starting at late evening or before the moon rises into your sky.

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If you trace the paths of these meteors backward on the sky’s dome, you’ll find that they appear to originate from a point in the sky near the the star Vega, the heavens’ 5th brightest star. This is the shower’s radiant point. The radiant point for the Lyrid shower sits just to the right of Vega, which is the brightest star in the constellation Lyra the Harp. It’s from Vega’s constellation Lyra that the Lyrid meteor shower takes its name.

EarthSky’s meteor shower guide for 2014

You don’t need to identify Vega in order to watch the Lyrid meteor shower. The idea that you must recognize a meteor shower’s radiant point in order to see any meteors is completely false. Any meteors visible the sky often appear unexpectedly, in any and all parts of the sky.

Why is the shower best between midnight and dawn? It’s because that’s when the star Vega – and the shower’s radiant point – is above your horizon. Vega rises above your local horizon – in the northeast – around 9 to 10 p.m. local time. It climbs upward through the night. The higher Vega climbs into the sky, the more meteors that you are likely to see. By midnight, Vega is high enough in the sky that meteors radiating from her direction streak across your sky. Just before dawn, Vega and the radiant point shine high overhead. That’s one reason the meteors will be more numerous then – at least on a night when the moon isn’t washing out meteors.

A close-up look of the constellation Lyra the Harp. Image credit: Wikimedia Commons. Click here to know more about Vega

So why near Vega? Why do the meteors radiate from this part of the sky? The radiant point of a meteor shower marks the direction in space – as viewed from Earth – where Earth’s orbit intersects the orbit of a comet. In the case of the Lyrids, the comet is Comet Thatcher. This comet is considered the “parent” of the Lyrid meteors. Like all comets, it is a fragile icy body that litters its orbit with debris. When the bits of debris enter Earth’s atmosphere, they spread out a bit before they grow hot enough (due to friction with the air) to be seen. So meteors in annual showers are typically seen over a wide area centered on the radiant, but not precisely at the radiant.

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In a good year, you’ll see perhaps 15 meteors per hour in a dark, moonless sky. That’s in contrast to the year’s best showers – the Perseids of August and Geminids of December – both of which typically produce about 60 meteors per hour.

Still, the April Lyrids can surprise you. They’re known to have outburts of several times the usual number – perhaps up to 60 an hour or so – on rare occasions. Meteor outburts are not predictable. So – like a fisherman – you must take your lawn chair, a thermos of something to drink, whatever other gear you feel you need – and wait. You’ll be reclining outside in a dark location, breathing in the night air and gazing up at the starry heavens. Not a bad gig.

Bottom line: On any clear night around April 20-23, the Lyrid meteor shower will kick off at late evening. Meteor numbers will tend to pick up after midnight, becoming greatest in the dark hour before dawn. In 2013, the waxing gibbous moon is interfering, but give the shower a try, anyway. It’s generally a fairly modest shower, perhaps offering 10 to 15 meteors per hour, but it can surprise you. Just remember – no matter where you are on Earth – the best time to watch the Lyrid meteor shower is during the wee hours of the morning after the moon sets.