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Bootes: Difference between revisions
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[[File:375px-Boötes IAU.svg.png|thumb|Bootes]] | [[File:375px-Boötes IAU.svg.png|thumb|Bootes]] | ||
[[ | [[Bootes]] is a constellation in the northern sky, located between 0° and +60° declination, and 13 and 16 hours ofright ascension on the celestial sphere. The name comes from the Greek Βοώτης, Boōtēs, meaning herdsman orplowman (literally, ox-driver; from boos, related to the Latin bovis, “cow”). The "ö" in the name is a diaeresis, not an umlaut, meaning that each 'o' is to be pronounced separately. | ||
One of the 48 constellations described by the 2nd century astronomer Ptolemy, Boötes is now one of the 88 modern constellations. It contains the fourth brightest star in the night sky, the orange-hued Arcturus. Boötes is home to many other bright stars, including eight above the fourth magnitude and an additional 21 above the fifth magnitude, making a total of 29 stars easily visible to the naked eye. Boötes is in a part of the celestial sphere facing away from the plane of our home Milky Way galaxy, and so does not have open clusters or nebulae. Instead, it has one bright globular cluster and many faint galaxies.<ref>[http://en.wikipedia.org/wiki/Bootes Bootes]</ref> | One of the 48 constellations described by the 2nd century astronomer Ptolemy, Boötes is now one of the 88 modern constellations. It contains the fourth brightest star in the night sky, the orange-hued Arcturus. Boötes is home to many other bright stars, including eight above the fourth magnitude and an additional 21 above the fifth magnitude, making a total of 29 stars easily visible to the naked eye. Boötes is in a part of the celestial sphere facing away from the plane of our home Milky Way galaxy, and so does not have open clusters or nebulae. Instead, it has one bright globular cluster and many faint galaxies.<ref>[http://en.wikipedia.org/wiki/Bootes Bootes]</ref> | ||
==Arcturus== | ==Arcturus== | ||
Located 36.7 light-years from Earth, Arcturus, or Alpha Boötis, is the brightest star in Boötes and the fourth brightest star in the sky at an apparent magnitude of −0.05;[21] It is also the brightest star north of the celestial equator, just shading out Vega andCapella. Its name comes from the Greek for "bear-keeper". An orange giant of spectral class K1.5III, Arcturus is an ageing star that has exhausted its core supply of hydrogen and cooled and expanded to a diameter of 27 solar diameters, equivalent to approximately 32 million kilometers. Though its mass is approximately one solar mass (M☉), Arcturus shines with 133 times the luminosity of the Sun (L☉). Some people on the earth are originally from Arcturus, and are called [[Arcturians]]. <ref>[http://en.wikipedia.org/wiki/Bootes Bootes]</ref> | |||
Located 36.7 light-years from Earth, Arcturus, or Alpha Boötis, is the brightest star in Boötes and the fourth brightest star in the sky at an apparent magnitude of −0.05;[21] It is also the brightest star north of the celestial equator, just shading out Vega andCapella. | |||
==Legend and Mythology== | ==Legend and Mythology== | ||