Vega

How to find it

In June, look high in the east after dark for a brilliant blue-white star. By August evenings it stands almost straight overhead from 40°N, and in October it is still well up in the west. No other star in that part of the sky comes close in brightness.

Vega is the brightest of the three stars of the Summer Triangle. Deneb in Cygnus marks the corner to the east-northeast and Altair in Aquila the corner to the southeast. Right beside Vega, a small parallelogram of faint stars outlines the body of the lyre. In spring, if you follow the handle of the Big Dipper in a long arc away from the bowl, you will be heading roughly toward where Vega rises late in the evening.

What kind of star it is

Vega is a young main-sequence star of type A0, meaning it still burns hydrogen in its core. It is about 25 light-years away, roughly twice as massive as the Sun and about 40 to 50 times as luminous. At about 700 million years old, it is far younger than the 4.6-billion-year-old Sun.

Its surface is about 17,000°F, much hotter than the Sun, which gives it a cool blue-white color. Because it is heavier and hotter, it will run through its fuel faster and live only around a billion years in total.

Notable features

Vega spins remarkably fast. Studies with linked telescopes in the 2000s found that it turns once in roughly 12 to 17 hours, compared with about 27 days for the Sun. The spin flattens it so that its equator is about a fifth wider than its poles and several thousand degrees cooler. We happen to look down almost onto one of its poles, which is why it took careful measurements to notice.

In 1983 the infrared satellite IRAS found that Vega gives off far more infrared light than a bare star should. The extra glow comes from a wide ring of dust, the first debris disk discovered around a main-sequence star. Images released in 2024 from the Hubble and Webb space telescopes show a disk about 100 billion miles across that is surprisingly smooth, with no clear gaps that would reveal large planets.

Vega also has a place in the history of measurement. It was used for many years as the reference point of the magnitude scale, which is why its magnitude sits almost exactly at zero. On the night of 16 to 17 July 1850, astronomers at Harvard College Observatory took a 90-second exposure of it, the first photograph of any star besides the Sun.

Name and history

The name comes from the Arabic al-nasr al-waqi, 'the swooping eagle', which pictured these stars as a bird with folded wings. In Ottoman Turkish astronomy texts it appears as en-Nesrü'l-vâkı. In China, Korea and Japan Vega is the weaver girl, separated from the herdsman Altair by the river of the Milky Way.

Earth's axis slowly traces a circle on the sky over about 26,000 years, a motion called precession. Around 14,000 years ago this brought the north celestial pole close to Vega, making it the brightest pole star our planet has known. The same cycle will make it a rough pole star again in about 12,000 years.

Observing tips

Vega is a good first star for checking color. Compare its blue-white light with orange Arcturus lower in the west on early summer evenings. High overhead it twinkles much less than stars near the horizon, so it is also a fine target for focusing a telescope.

No amateur telescope can show the dust disk or the flattened shape; those need space observatories and linked professional telescopes. Instead, point binoculars about 2 degrees east-northeast of Vega to find Epsilon Lyrae, which splits into two stars, and then use a small telescope to see that each is itself a close pair. Vega stays visible from 40°N for much of the year, so you can follow it from summer nights to winter dusk.