Index: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Spica ( α Virginis) is a brilliant first- magnitude star, believed to be the star that provided Hipparchus with the data which enabled him to discover precession of the equinoxes. The temple at Thebes was oriented with reference to Spica in about 3200 B.C. when it was constructed, and over time, precession resulted in a slow but noticeable change in the orientation of Earth relative to Spica using the temple's fixed orientation and construction date to compare against. Nicolaus Copernicus also made a lot of observations of Spica with his home-made triquetrum for his researches on precession.The name Spica derives from the Latin spica, an ear of grain.
An easy way to find Spica is to follow the arc of the handle of the Big Dipper to Arcturus (α BoötisBootes Abbreviation Boo Genitive Bootis Meaning in English the Herdsman Right ascension 15 h Declination 30° Visible to latitude Between 90° and −50° Best visible June Area Total Ranked 13th907 sq. Number of stars with apparent magnitude 3 Brightest), and then continue on the same distance to Spica.
Some facts about Spica
- Distance from Earth : 262 light-years
- Spectral type: B1 V
- Radial velocityRadial velocity is the velocity of an object in the direction of the line of sight. The light of an object with a substantial radial velocity will be subject to Doppler effect, so the wavelength of the light increases for receding objects (redshift) and d: 1 km/s
- Proper Motion: 0.053 arcsecs/year
- Apparent Visual Brightness ( Sirius A = 1): 0.108
- Apparent Visual Magnitude: 0.98
- Absolute Visual Magnitude: -3.55
- LuminosityIn physics, luminosity is the density of luminous intensity in a given direction. In astronomy, luminosity is the amount of energy a body radiates in unit time. It is typically expressed in the SI unit watts or in terms of solar luminosities, L; that is,: 2.5e4 Solar Luminosities
Spica is also the first Slovene astronomical magazine, edited by Bojan Kambic and published since 1995 (Slovene Spika).
Stars
Virgo constellation
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