Vega. Vega (α Lyr, α Lyrae, Alpha Lyrae) is the brightest star in the constellation Lyra, the fifth brightest star in the night sky and the second brightest star in the northern celestial hemisphere, after Arcturus. It is a relatively close star at only 25 light-years from Earth, and, together with Arcturus and Sirius, one of the most luminous stars in the Sun's neighborhood. Vega is only about a tenth of the age of the Sun, but since it is 2.1 times as massive its expected lifetime is also one tenth of that of the Sun; both stars are at present approaching the midpoint of their life expectancies. Vega has an unusually low abundance of the elements with a higher atomic number than that of helium.[8] Vega is also a suspected variable star that may vary slightly in magnitude in a periodic manner.[13] It is rotating rapidly with a velocity of 274 km/s at the equator.
Based on an observed excess emission of infrared radiation, Vega appears to have a circumstellar disk of dust. Visibility[edit] Ring Nebula. The Ring Nebula (also catalogued as Messier 57, M57 or NGC 6720) is a planetary nebula in the northern constellation of Lyra.[5] Such objects are formed when a shell of ionized gas is expelled into the surrounding interstellar medium by a red giant star, which was passing through the last stage in its evolution before becoming a white dwarf. History[edit] This nebula was discovered by the French astronomer Antoine Darquier de Pellepoix in January 1779, who reported that it was "...as large as Jupiter and resembles a planet which is fading.
" Later the same month, fellow French astronomer Charles Messier independently found the same nebula while searching for comets. It was then entered into his catalogue as the 57th object. Messier and German-born astronomer William Herschel speculated that the nebula was formed by multiple faint stars that were unresolvable with his telescope.[6][7] Observation[edit] Location of M57 in the constellation Lyra. Properties[edit] Nebula structure[edit] Messier 56. Messier 56 with amateur telescope Messier 56 (also known as M56 or NGC 6779) is a globular cluster in the constellation Lyra. It was discovered by Charles Messier on January 19, 1779. The cluster is located almost midway along an imaginary line between Albireo (β Cygni) and Sulafat (γ Lyrae).
It is a challenge to find with large (50–80 mm) binoculars, appearing as a slightly fuzzy star.[8] The cluster can be resolved using a telescope with an aperture of 8 in (20 cm) or larger.[9] M56 is at a distance of about 32,900[3] light-years from Earth and measures roughly 84 light-years across, with a combined mass some 230,000[4] times that of the Sun. The brightest stars in M56 are of 13th magnitude, while it contains only about a dozen known variable stars, such as V6 (RV Tauri star; period: 90 days) or V1 (Cepheid: 1.510 days);[11] other variable stars are V2 (irregular) and V3 (semiregular).
References[edit] Jump up ^ Shapley, Harlow; Sawyer, Helen B. External links[edit] Coordinates: Lyra_IAU. Lyra. Lyra is visible from the northern hemisphere from spring through autumn, and nearly overhead, in temperate latitudes, during the summer months. From the southern hemisphere, it is visible low in the northern sky during the winter months. [citation needed] Notable features[edit] The constellation Lyra as it can be seen by the naked eye. Stars[edit] Lyra's brightest stars include the following:[3] α Lyr (Vega). Deep-sky objects[edit] Messier 56 is composed of a large number of stars, tightly bound to each other by gravity.[4] In Lyra are the objects M56, M57, and Kuiper 90.
Kuiper 90 is also known as 17 Lyrae C (Gliese 747AB), a red dwarf system near 17 Lyrae, but 26 light years from the Sun. BD +36 3317 [1], a white star in the young open cluster Stephenson 1, was discovered as a binary eclipsing system by Violat-Bordonau in 2008; its period is 4.30216 days; its other name is VSX J185422.2+365107.[9] Exoplanets[edit] An image showing Lyra History[edit] Mythology[edit] In History[edit] Cygnus, Lyra.