How many stars in lyra

Models of how stars age indicate that, like the Sun, Vega is about halfway through its "normal" lifetime -- the time when it fuses the hydrogen atoms in its core to make helium. But stellar lifetimes aren't all the same. Vega is probably around one-tenth the age of the Sun, so it has only a few hundred million years to go, versus billions of years for the Sun.

The difference is the mass of the two stars. Vega is more than twice as heavy as the Sun, so it burns through its hydrogen much faster than the Sun does. So Vega will finish its hydrogen, puff up to become a red giant, blow its outer layers off into space, and fade into obscurity as a white dwarf -- all while the Sun continues to shine much as it does today.

The constellation's second-brightest star, Beta Lyrae , stands a bit to the south of Vega. Beta Lyrae is a binary, so it consists of two stars locked in a mutual orbit around each other. Both stars are larger, hotter, and brighter than the Sun. One star is blue, and the other is white. The stars are so close together that each star's gravity has distorted the other, making them look like eggs.

The two stars are so close together that they orbit each other once every 13 days. And during every orbit, one star passes in front of the other as seen from Earth, blocking its light.

Not only is it a nice stellar pair to enjoy through binoculars, but the brighter sun, known as Beta A, is also an eclipsing binary. Every The Beta A system is unusual in that both stars mutually cover each other as they orbit a common center of gravity. Each lies so close to the other that the complex interplay of gravity dramatically distorts them into egg-shaped ellipsoids as swirling clouds engulf both. When Beta is near maximum, its appearance matches that of Gamma Lyrae to its immediate east.

When near minimum, it closely matches Zeta A. Gamma, at the southeast corner, is a solo act. Also known by the proper name Sulafat, Gamma is a type B9 blue giant emitting over 2, times more energy than the Sun. While no companion stars are physically associated with Gamma, it serves as the centerpiece for an asterism that, to me, looks like a compact, if not damaged, fan-shaped leaf rake.

Two stars, 4. And like the Double-Double, the Deltas can be resolved by eye alone given dark skies. Through binoculars, the Deltas do much more than just split. American astronomer Charles Stephenson was first to suggest that the Deltas, along with some of the fainter surrounding suns, form a weak grouping.

That was back in There was some debate in the ensuing years as to whether or not the stars actually form a true cluster, but that was all put to rest in Studies conducted by a team led by American astronomer Olin Eggen proved that the cluster was real and contained some 33 members.

The cluster is now appropriately nicknamed the Delta Lyrae Cluster, but is more formally known as Stephenson 1, for his original research. I heard from reader Rob Datsko that there is an intriguing double triangle asterism within Stephenson 1. As he envisions it, orangish Delta2 forms the east-pointing apex of an obtuse triangle that includes Delta1 to the northwest and 7th-magnitude SAO to the south.

Have you ever spotted a noteworthy pattern of stars through your binoculars? Do as Rob did and tell me about it. Contact me through my website, philharrington.

Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. View our Privacy Policy. By signing up you may also receive reader surveys and occasional special offers. We do not sell, rent or trade our email lists. It is bordered by Vulpecula to the south, Hercules to the east, Draco to the north, and Cygnus to the west. Vega, the brightest star in Lyra, forms a large triangle with two other stars, Altair in Aquila and Deneb in Cygnus.

This prominent formation of bright stars is known as the Summer Triangle. Lyra is also the origin point for the annual Lyrids meteor shower which occurs every year in April. Lyra is one of the 48 constellations listed by the Greek astronomer Ptolemy in the second century.

It represents the lyre, a musical instrument with strings that resembles a harp. It is associated with the myth of the Greek musician Orpheus.

The lyre was invented by Hermes as a gift to his half-brother Apollo, who gave it to Orpheus, the musician of the Argonauts. Orpheus was so gifted with his music that even inanimate objects such as trees, streams, and rocks could be charmed. After his death, his lyre was thrown into a river. Zeus sent an eagle to retrieve it and both Orpheus and the Lyre were placed in the heavens as constellations. Lyra is a small, dim constellation, but it is home to the fifth brightest star in the sky, Vega.