• Peg - Pegasus the Flying Horse

    IAU Constellation
    Peg - Pegasus the Flying Horse

    Size

    7 of 88
    Astronomical Regions
    Northern

    Intro and Visual description

    Farther along on the line from the Pointers to Polaris and Cassiopeia is a large, nearly perfect square of four stars. This is the Great Square of Pegasus. Pegasus, the Winged Horse, lies almost directly overhead in autumn. Located east of Andromeda; signals the coming of Fall. Because Pegasus flies so fast, his hind quarters can’t be seen.

  • Fusion Image 9

    Source: Johann and Elisabeth Hevelius, Uranographia ("Map of the Heavens"; Gdansk, 1690); History of Science Collections, University of Oklahoma Libraries
    Object: M15, in Sagittarius the Archer; Hubble Space Telescope, WikiSky
    Composite: The Sky Tonight, skytonight.org (CC-by)
    Fusion Image 9
    Constellations IAU Abbr
    Peg

    Source Description

    The Uranographia of Hevelius, the most detailed and influential celestial atlas of the 17th century, contains 54 beautiful double-page engraved plates of 73 constellations, and 2 oversized folding plates of planispheres.

    Unique among the major star atlases, Hevelius depicted the star patterns as if from the outside looking in, not as seen when looking up into the night-time sky. Consequently, Hevelius’ constellation figures provided an influential model for the production of artfully-designed celestial globes.

    The full title of the Uranographia pays tribute to the Polish king, John III Sobiesci. Hevelius created a new constellation, Scutum, the “Shield of Sobiesci,” representing the king’s defense of Europe against the Turks.

  • Fusion Image 10

    Source: Johann Bayer, Uranometria ("Measuring the Heavens"; Ulm, 1661); History of Science Collections, University of Oklahoma Libraries
    Object: NGC 7331 in Pegasus the Flying Horse; Vicent Peris (CC-by-sa)
    Composite: The Sky Tonight, skytonight.org, CC-by-sa)
    Fusion Image 10
    Constellations IAU Abbr
    Peg

    Source Description

    First published in Augsburg in 1603, Bayer’s atlas consists of 51 double-page copperplate engravings. Bayer labeled the stars with Greek letters, according to their apparent magnitude.

    Bayer-1661

  • Great Square of Pegasus

    Asterism Visual Appearance

    Andromeda contains one corner of the Great Square of Pegasus (the star Alpheratz).

  • Bode (1801), Plate 1: Aries Planisphere

    Bode-1801-01-planisphere

    Uranographia Tab I. Stellatum Hemisphaeri um Arietis. 

    Bode included two planisphere plates. They are not southern and northern hemispheres; each one has Polaris at the top and the south pole at the bottom. Each one is centered upon an equinox point (where the ecliptic or path of the Sun and the celestial equator intersect). The March equinox point was in Aries in antiquity; by Bode’s time, due to the precession of the equinoxes, it had shifted to Pisces. The September equinox point was in Libra in antiquity; by Bode’s time it had shifted to Virgo.  Bode titled the plates as the Aries and Libra planispheres.

    The Aries planisphere, centered on the March equinox in Pisces, includes these constellations, among others, which appear high overhead in the night skies of autumn:

    Equatorial:  Orion, Taurus, Harpa Georgii, Cetus, Aries, Pisces, Pegasus, Aquarius, Aquila, Scutum.

    Northern:  Auriga, Perseus, Andromeda, Cassiopeia, Draco, Honores Frederici, Cepheus, Cygnus, Lyra.

    Southern:  Eridanus, Apparatus Chemicus, Machina Electrica, Apparatus Sculptoris, Horologium, Toucan, Phoenix, Grus, Indus, Pavo, Tubus Astronomicus, Octans Nautica, Microscopium, Sagittarius, Globus Aerostatic.

    In March, the Aries-Pisces equinox (the center of the Aries planisphere) is traveling with the Sun, rising in the east in the mornings and setting in the west in the evenings. Imagine the center of the planisphere has the Sun pinned to it for that day, and that’s how it would move across the sky. Therefore the constellations near the center of this planisphere are invisible in the daytime sky at that time unless there is a solar eclipse. They would be visible directly opposite the Sun at the September equinox.