Cetus
- Aries
- Pisces
- Aquarius
- Sculptor
- Chemical oven
- Eridanus
- Taurus
The whale, fachsprachlich Cetus (Latin ), is a constellation in the area of the celestial equator.
Description
The whale is a very extensive, but little conspicuous constellation of the autumn sky between the fish and the river Eridanus. The largest part extends below the celestial equator, so it is not particularly high in our latitudes above the horizon.
The constellation has no distinct shape, since most of its stars have a lower brightness than 3 m and thus are not very noticeable.
The whale is the well-known variable star Mira and Tau Ceti, a yellow dwarf star located only 11.9 light years away, which is similar to our sun.
History
In ancient Mesopotamia saw the constellation as a sea monster Tiamat, which embodied the original cosmic feminine principle.
Since the constellation below the ecliptic lies, pull the sun, moon and planets over it. In the early Greeks, the stars will thus represented the entrance to the underworld dar. was later identified the constellation as the sea monster in connection with the legend of Andromeda.
Ptolemy took the constellation on in his description of the 48 constellations.
After the Frisian pastor David Fabricius discovered the star o Ceti in 1596 in the constellation, Johann Ph. Holwarda recognized in 1639 that changed the brightness of the star during the year strong. In 1662 he was baptized by Johann Hevelius " Mira ", the " Miraculous ". The discovery was of great importance, but they refuted the prevailing theory at the time, the stars were eternal and unchanging.
1807 was discovered in the whale, the fourth asteroid Vesta.
Mythology
In Greek mythology, the whale was a sea monster, presumably Keto or keto, the beautiful Andromeda, daughter of King Cepheus and Cassiopeia, should be sacrificed. Cassiopeia had the Nereids, the daughters of the sea god Nereus, insulted by claiming to surpass their beauty still. The Nereids turned to the sea god Poseidon and demanded the punishment of the vain Cassiopeia. Poseidon sent a sea monster then from that struck the coasts of Cepheus ' kingdom. An oracle after the beast could only be appeased by Andromeda, the only child of the royal couple, was sacrificed to it. Andromeda was chained to a rock and awaited their fate, but was saved at the last moment by the hero Perseus, who killed the monster. To reward he got for his wife Andromeda.
Cepheus, Cassiopeia, Andromeda and Perseus were also immortalized as constellations in the sky.
Celestial objects
Stars
The brightest star in the whale, β Ceti is 96 light-years from the Sun. He is an orange giant star of spectral type K0.
The name Deneb Kaitos is of Arabic origin and means "tail of the whale ."
α Ceti is 220 light years distant red giant of spectral type M1. The ancient Arabic name Menkar could be derived from " shoulder ", " snout" or " nostrils ".
τ Ceti ( Tau Ceti ) is at a distance of only 11.9 light years one of the nearest neighbors of the sun.
Double stars
γ Ceti ( Kaffaljidhm ) is a binary star system 82 light years away, which consists of a whitish bright main star of spectral type A2 and a yellowish companion of class G5. The pair of stars can be resolved with an average telescope into individual stars.
κ Ceti is 100 light years away and consists of two stars of spectral classes F2 and G1. The two stars have from the earth to a wide angular distance of 184 arc seconds and are already recognizable in a prism binoculars as single stars.
The system 66 Ceti is 70 light years away and consists of two stars of spectral types F8 and G4. Due to the angular separation of 16.5 arc seconds is sufficient to separate a small telescope.
Variable Stars
The 417 light years distant star Mira ( ο Ceti ) changes its brightness periodically over a period of around 332 days. It may take up to 2 m conspicuously bright in the maximum, a minimum, the brightness drop to 8 to 10 m. It is then visible to the naked eye.
The star is named after a group of variable stars, the Mira variables. It is pulsationsveränderliche stars, then swell and contract rhythmically again. Mira stars are red giants or supergiants with a relatively cool surface of 3,000 Kelvin. Their luminosity is still 100.00 times higher than that of our sun, as they can have huge diameter of several billion kilometers.
Messier and NGC objects
In the whale, there are several galaxies, two of which can already be observed with a small telescope.
M 77 is a bright Seyfertgalaxie type Sb with a distance of 50 million light years, it is the most distant object Messier.
NGC 246 is a 1,500 light years distant planetary nebula. In a telescope it is seen as a nebulous discs in which there are two stars of the 12th magnitude. One of the stars is a white dwarf star, the remnant of a star that has shed its outer shell of gas.
NGC 247 is a spiral galaxy of type SD in 8 million light years away. It was discovered in 1784 by William Herschel. From Earth, the galaxy can be seen in edge position. In a telescope it appears as a narrow Nebula.