constellation Virgo

    Caption: Constellation Virgo (The Virgin) (zodiac symbol ♍) on a sky map of a portion of the celestial sphere.

    Features:

    1. Virgo is a traditional zodiac constellation and one of the IAU-defined 88 constellations.

    2. The International Astronomical Union (IAU) is the international organization of astronomers which has arrogated to itself the right to name things in the sky.

    3. The IAU-defined 88 constellations are actually patches (i.e., patches of solid angle) on the celestial sphere which tile it completely without overlap. Thus, any point astronomical object at one time is in one and only one constellation (i.e., IAU-defined 88 constellation).

      Thus, all point astronomical objects can be uniquely located by constellation: e.g., point astronomical object X is in Virgo.

      Of course, extended astronomical objects can straddle multiple constellations.

    4. Virgo is crossed by the ecliptic---which is why it is a zodiac constellation.

    5. The Sun moving eastward on the ecliptic (which to the left on the sky map) is in constellation Virgo (which is NOT the same as astrological sign Virgo) approximately in the period Sep16--Oct30 (∼ 43 days) (see Wikipedia: Zodiac: Table of Dates).

    6. The brightest star in Virgo is Spica (α VIR).

    7. The Virgo Cluster (a rich galaxy cluster) is roughly centered in Virgo. The Virgo Cluster also extends into constellation Coma Berenices.

      Note Coma Berenices (Berenice's Hair) is the only IAU designated constellation named for an actual historical person or at least their hair: Queen Berenice II of Egypt (267/266--221 BCE), an ancestress of Cleopatra (69--30 BCE).

    8. Note that cD (giant elliptical) galaxy M87 is close to the center of the main part of Virgo Cluster (see Wikipedia: Virgo Cluster: Characteristics, Wikipedia: M87: Environment). M87 is in Virgo though very near the boundary with Coma Berenices as the sky map shows.

    Credit/Permission: © IAU, Sky & Telescope magazine (Roger W. Sinnott & Richard Tresch Fienberg) 2011 (uploaded to Wikipedia by User:Kxx, 2011) / Creative Commons CC BY-SA 3.0.
    Image link: Wikimedia Commons: File:Virgo IAU.svg.
    Local file: local link: iau_virgo.html.
    File: Constellation file: iau_virgo.html.