The constellation Cetus, the sea monster, can be seen in the northern hemisphere in the late fall and early winter. It is visible at latitudes between 70 degrees and degrees. It is a very large constellation, occupying a total area of 1, square degrees. It is actually the 4th largest constellation in the night sky. It lies in a region of the sky called the Water. Other water-related constellations in this area include Eridanus the river , Aquarius the water bearer , and Pisces the fish. Cetus is one of the constellations cataloged by the Greek astronomer Ptolemy in the second century.
The constellation contains only one Messier object, a large galaxy called M77, but it is home to several notable stellar objects, amongst which is the red giant, Omicron Ceti, which defines an entire class of variable stars, as well as 14 stars with confirmed planets.
There are found a group of other constellations evoking watery images, including Eridanus a river , Aquarius the water bearer , and Pisces fish , Piscis Austrinus southern fish , Capricornus sea-Goat , and Aquarius water-carrier. To ward off disaster, the Oracle of Apollo proposed that the King and Queen sacrifice their daughter to the sea monster, but before the monster could devour the princess, the young hero Perseus happened by and rescued Andromeda after killing the monster.
It is an orange giant star K0 III , meaning that it has evolved off the main sequence, and is rapidly turning into a red giant. Viewed through a telescope, it appears to be a double star with a faint blue-white companion, 93 Ceti, although the two are not physically related. As for poor, ugly Cetus. He also represents the gates to the underworld thanks to his position just under the ecliptic plane. Arab legend has it that Cetus carries two pearl necklaces — one broken and the other intact — which oddly enough, you can see among its faint stars in the circular patterns when nights are dark.
No matter what the legends are, Cetus is an rather dim, but interesting constellation! Cetus was one of many Mesopotamian constellations that passed down to the Greeks. Originally, Cetus may have been associated with a whale, and is often referred to as the Whale. However, its most common representation is that of the sea monster that was slain by Perseus.
However, Cetus has also been variously depicted with animal heads attached to an aquatic animal body. The constellation is also represented in many non-Western astrological systems.
This star has left its main sequence and is on its way to becoming a red giant. Then comes Omicron Ceti, also known as Mira, binary star consisting located approximately light years away.
This binary system consists of an oscillating variable red giant Mira A. After being recorded for the first time by David Fabricius on August 3, , Mira has since gone on to become the prototype for the Mira class of variables of which there are six or seven thousand known examples. These stars are red giants whose surfaces oscillate in such a way as to cause variations in brightness over periods ranging from 80 to more than 1, days.
Mira was the first non-supernova variable star discovered, with the possible exception of Algol in the constellation Perseus , which was confirmed as a variable only in Mira is believed to be about six billion years old.
The companion star, Mira B, is a high temperature white dwarf that is accreting mass from the red giant. The two form a symbiotic pair, the closest one of its kind to the Sun. Mira is the brightest periodic variable star that cannot be seen by the unaided eye during a part of its cycle.
It has a period of days. Its variability was first documented by the German astronomer David Fabricius in Fabricius believed it was a nova until he saw the star again in The star is shedding a trail of material from its outer envelope. Tau Ceti is a cool class G G8. It is one of the nearest stars to our solar system, lying only It has a mass only about 78 percent that of the Sun and is one of the very few stars less massive than the Sun that are nevertheless visible to the unaided eye.
It is a metal-deficient star with a high proper motion. Messier 77 is a barred spiral galaxy in Cetus, approximately 47 million light years distant and , light years in diameter. It has an apparent magnitude of 9. The galaxy can be easily found 0. Bernard Yarnton Mills was the first to discover this. He designated the object Cetus A. NGC lies only 0.
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