Lyra

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http://images Lyra system.

Abbreviation: Lyr

English name: Lyra

Pronounced : /ˈlaɪrə/, Latin: lyre

Particulars: Spectroscopic binary beta Lyr Binaries delta Lyr, zeta Lyr, a 11871 Quadruple star epsilon Lyr Planetary nebula M 57 Globular star cluster M 56 Meteor Showers: Lyrids, June Lyrids, Alpha Lyrids.

A small but bright northern constellation lying between DECL=+30 and DECL=+40 and RA=18h and RA=19h. The fifth-brightest star of the sky, alpha Lyr, called Vega (arabic for "stone eagle"), radiates from the top Lyra with a pure white colour. Together with alpha Cyg, Deneb , and alpha Aql, Atair, Vega forms the Summer Triangle.

Stars and other objects:

It's easy to find Lyra, the harp, by first finding Vega — one of the brightest stars in Earth's night sky. Look for Vega high overhead in mid-summer. Lyra looks like a small, lopsided square, with Vega just beside one of the corners of the square. Beta Lyr is a half separated eclipsing binary of a cream-white colour. The brightness varies from 3.4 mag to 4.3 mag every twelve days and 22 hours. With larger telescopes beta Lyr is resolved as an attractive double star with an blue companion of 8th mag. Additionally two other 9th mag companions can be seen in small telescopes). Another double variable is delta Lyr. With the help of binoculars you can view a blue-white star of 6th mag and a semi-regular red giant. The brightness of the latter varies erratically from 4th to 5th magnitude. An easy object with binoculars or small telescopes is zeta Lyr consisting of a 4th and a 6th mag star.

One of the most celebrated quadruple stars in the sky is epsilon Lyr. It is commonly known as the Double Double. In a very clear, moonless night it is possible to see the wide pair of 5th mag stars. Each star of this double is an double itself. But to resolve them a telescope with at least 60 mm aperture and a high magnification is needed.

The binary a 11871 requires telescopes with an aperture of at least 12cm for resolution. The two stars orbit each other with a period of 62 years. The famous Ring Nebula, M 57, is perhaps somewhat disappointing when viewed through amateur telescopes but really terrific on long-exposure photographs. In small telescopes it presents itself on dark nights as a ghostly elliptical disk. Its apparent size is larger than that of Jupiter. To see the central hole a telescope of at least 150 mm aperture is needed. The central, very blue star is so faint that it is beyond the power of amateur telescopes to be revealed. The nebula can be found half way between beta Lyr and gamma Lyr.

Three meteor showers seem to radiate from this constellation: the Lyrids, the June Lyrids and the Alpha Lyrids. The latter two are active in the summer time. The Alpha Lyrids are visible from july, 9th, to july, 20th, and reach their maximum activity on the 14th of july. As the name suggests the June Lyrids can be observed in june, from the 10th to the 21st reaching the maximum on the 15th with an hourly rate of about 8 meteors. The Lyrids are typically visible from April, 16th, to April 25th, with its maximum around the 20th to 21st.

Mythology

http://images Lyre instrument

The lyre is one of the most ancient of musical instruments. For example, in the royal city of Ur (circa 3000 BC) musicians played the lyre for royalty, according to excavated artifacts.

In Greek mythology, the lyre was invented by Hermes. When only a child, he pulled a cow-gut across a tortoise shell, and thereby created the lyre. Hermes gave this lyre to his half-brother Apollo (both were fathered by Zeus). As the god of music, Apollo became associated with the instrument

The lyre of Orpheus is also thrown into the river, and it too floats to Lesbos, beached near the temple of Apollo. Apollo then convinces Zeus that the instrument should become a constellation. Zeus agrees, and places the lyre of Orpheus between Hercules and Cygnus.

External links

• Lyra
• Lyra System
• Lyra Maps

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