天文学上的天秤座.ppt

• Libra is one of the zodiac constellation located between Virgo and Scorpio. There are more than ten pieces of this constellation can be seen by ten 8-inch (20 cm) or larger telescope. Four brightest stars in the constellation ----α, β, γ, σ form a quadrilateral. • Libra α Star: is called “dixiu1” in chinese and Libra α is an eclipsing binary like Perseus β.• Libra β is called “dixiu4” in chinese, it is the only green star can be seen by the naked eye In the day.• Libra's stars had been recognized since ancient times, but Ptolemy did not put it as a separate constellation. In Ptolemy’s Constellation, it was Scorpion’s claw .• Libra α is the north Scorpio claw ------ “North sequestration“ ,and Libra βis the south Scorpio claw ------“South sequestration“ • However, until the 1st century AD Roman Caesar era, they found that it is Harvest when the sun move to these stars.So they made these stars a constellation---Libra.• Libra can be seen out of Arctic Circle .•Libraβ dixiusi Zubenelchemale - 2.61 - Libraα dixiuyi Zubenelgenubi - 2.75 Double Star Libraσ zheweiqi Zubenalgubi - 3.29 - Libraγ dixiusan - - 4.00 - Libraι dixiuer - - 4.50 - Libraδ - - - - - Libraμ - - - - - Libraε - - - - - Libraν - - - - - Libraη xixiansi - - - - Libraθ xixiansan - - - - Libraλ - - - - - Libraυ dafuyi - - 3.58 - Libraτ dafuer - - 3.66 - Libra4 zheweiwu - - - - Libra12 zheweiliu - - - - Libra48 xixianer - - - - 。