The twelve charts show the night sky at 22.30h on the 21st of each month from June 2007 at summer solstice,
through winter solstice in December, to May 2008. Positions of the planets will change, but the constellations will remain the same for all years.
Dates have been allotted to demonstrate the changing position of the elliptic. Thus we hereby demonstrate:
a) the changing constellations throughout the year, and
the relative movement of the ecliptic showing how the Sun, Moon and planets rise and set at different points along the horizon over
the course of the year. It also shows how the more distant planets remain against the same pattern of stars over a long period (Neptune
in Capricorn, Uranus in Aquarius, Saturn in Leo and Jupiter in Ophiuchus) whilst the closer planets move more quickly against a changing pattern of stars.
On any night, if you watch from dusk to dawn, certain stars rise in the east and move across the sky to set in the west. Over a period
of time, stars that were low on the western horizon on the first night of observation will disappear and their place taken by stars that
were previously higher in the sky. Earth completes a rotation on its axis in 23 hours 56 minutes (4 minutes short of 24 hours) and, as a
result the stars appear to rise, cross the sky and set 4 minutes earlier each night – an hour earlier in 15 days, 2 hours earlier in 30
days, with a full circle completed within the course of a year.
It is usual to refer to 88 constellations that can be seen around the world, 6 of which can be seen only in the northern hemisphere
and 14 only in the southern hemisphere. The remaining 68 can be seen in both hemispheres at different times of the year. The constellations
along the ecliptic are the signs of the zodiac.
The 6 constellations visible throughout the year in the northern hemisphere (shown in yellow), sometimes called circumpolar constellations, are
Cassiopeia(2), Cepheus(3), Draco(4),
Ursa Major(5) and Ursa Minor(6).
The 16 spring constellations in the northern hemisphere (shown in green) are Antlia(7), Bootes(8),
Cancer(9), Canes Venatici(10), Centaurus(11),
Coma Berenices(12), Corvus(13), Crater(14),
Hydra(15), Leo(16), Leo Minor(17), Lupus(18),
Lynx(19), Pyxis(20), Sextans(21) and Virgo(22).
The 21 northern hemisphere summer constellations (shown in red) are Aquila(23), Ara(24),
Capricorn(25), Corona Australis(26), Corona Borealis(27),
Cygnus(28), Delphinus(29), Equuleus(30),
Hercules(31), Indus(32), Libra(33),
Lyra(34), Microscopium(35), Ophiuchus(36),
Scorpio(37), Scutum(38), Serpens(39),
Sagitta(40), Sagittarius(41), Telescopium(42)
The 13 northern hemisphere autumn constellations (shown in orange) are Andromeda(44), Aquarius(45),
Aries(46), Cetus(47), Grus(48), Lacerta(49),
Pegasus(50), Perseus(51), Phoenix(52),
Pisces Austrinus(53), Pisces(54), Sculptor(55)
The 18 northern hemisphere winter constellations (shown in white) are Auriga(57), Caelum(58),
Canis Major(59), Canis Minor(60), Carina(61),
Columba(62), Eridanus(63), Fornax(64),
Gemini(65), Horologium(66), Lepus(67),
Monoceros(68), Orion(69), Pictor(70),
Puppis(71), Reticulum(72), Taurus(73)
The 14 southern hemisphere constellations are Apus, Chamaeleon,
Circinus, Crux, Dorado, Hydrus,
Mensa, Musca, Norma, Octans,
Pavo, Triangulum Australe, Tucana