Beta Ceti
Encyclopedia
Beta Ceti is the brightest star
in the constellation
Cetus
. Although it has the Bayer designation
"beta", it is actually brighter than Alpha Ceti
. It has the traditional names Deneb Kaitos and Diphda. This orange giant is easy to identify due to its location in an otherwise dark section of the celestial sphere
.
on the border between G and K, making it a yellowish star somewhat cooler than the Sun
. In spite of its cooler temperature, Deneb Kaitos is much brighter than the Sun with a bolometric
luminosity of about 145 L☉ resulting from a mass that is 3M☉
and a radius of about 17R☉. Deneb Kaitos appears to be an older star having left the main sequence
on its way to its red giant
evolutionary
phase. With an apparent magnitude
of 2.04 it ranks among the brighter stars in the night sky, having an absolute magnitude
of −0.31. At only 96 light years
from the Earth
, Deneb Kaitos is one of the nearer stars of a bright apparent magnitude. It can be located at declination
−17° 59' 11.8" and right ascension
of 00:43:35.37 (2000).
).
In Chinese astronomy
, Deneb Kaitos is called 土司空, Pinyin
: Tǔsīkōng, meaning Master of Constructions, because this star is marking itself and stand alone in Master of Constructions asterism, Legs
mansion (see : Chinese constellation
). 土司空 (Tǔsīkōng), westernized into Too Sze Kung by R.H. Allen and the meaning is "Superintendent of Earthworks."
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
in the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
Cetus
Cetus
Cetus is a constellation. Its name refers to Cetus, a sea monster in Greek mythology, although it is often called 'the whale' today. Cetus is located in the region of the sky that contains other water-related constellations such as Aquarius, Pisces, and Eridanus.-Ecliptic:Although Cetus is not...
. Although it has the Bayer designation
Bayer designation
A Bayer designation is a stellar designation in which a specific star is identified by a Greek letter, followed by the genitive form of its parent constellation's Latin name...
"beta", it is actually brighter than Alpha Ceti
Alpha Ceti
Alpha Ceti is a star in the constellation of Cetus. It has the traditional name Menkar or Menkab. The name Menkar derives from the Arabic word منخر manħar "nostril" ....
. It has the traditional names Deneb Kaitos and Diphda. This orange giant is easy to identify due to its location in an otherwise dark section of the celestial sphere
Celestial sphere
In astronomy and navigation, the celestial sphere is an imaginary sphere of arbitrarily large radius, concentric with the Earth and rotating upon the same axis. All objects in the sky can be thought of as projected upon the celestial sphere. Projected upward from Earth's equator and poles are the...
.
Properties
Deneb Kaitos has a stellar classificationStellar classification
In astronomy, stellar classification is a classification of stars based on their spectral characteristics. The spectral class of a star is a designated class of a star describing the ionization of its chromosphere, what atomic excitations are most prominent in the light, giving an objective measure...
on the border between G and K, making it a yellowish star somewhat cooler than the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
. In spite of its cooler temperature, Deneb Kaitos is much brighter than the Sun with a bolometric
Bolometer
A bolometer is a device for measuring the power of incident electromagnetic radiation via the heating of a material with a temperature-dependent electrical resistance. It was invented in 1878 by the American astronomer Samuel Pierpont Langley...
luminosity of about 145 L☉ resulting from a mass that is 3M☉
Solar mass
The solar mass , , is a standard unit of mass in astronomy, used to indicate the masses of other stars and galaxies...
and a radius of about 17R☉. Deneb Kaitos appears to be an older star having left the main sequence
Main sequence
The main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell...
on its way to its red giant
Red giant
A red giant is a luminous giant star of low or intermediate mass in a late phase of stellar evolution. The outer atmosphere is inflated and tenuous, making the radius immense and the surface temperature low, somewhere from 5,000 K and lower...
evolutionary
Stellar evolution
Stellar evolution is the process by which a star undergoes a sequence of radical changes during its lifetime. Depending on the mass of the star, this lifetime ranges from only a few million years to trillions of years .Stellar evolution is not studied by observing the life of a single...
phase. With an apparent magnitude
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...
of 2.04 it ranks among the brighter stars in the night sky, having an absolute magnitude
Absolute magnitude
Absolute magnitude is the measure of a celestial object's intrinsic brightness. it is also the apparent magnitude a star would have if it were 32.6 light years away from Earth...
of −0.31. At only 96 light years
Light Years
Light Years is the seventh studio album by Australian recording artist Kylie Minogue. It was released on 25 September 2000 by Parlophone and Mushroom Records. The album's style was indicative of her return to "mainstream pop dance tunes"....
from the Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
, Deneb Kaitos is one of the nearer stars of a bright apparent magnitude. It can be located at declination
Declination
In astronomy, declination is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. Declination in astronomy is comparable to geographic latitude, but projected onto the celestial sphere. Declination is measured in degrees north and...
−17° 59' 11.8" and right ascension
Right ascension
Right ascension is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. The other coordinate is the declination.-Explanation:...
of 00:43:35.37 (2000).
Etymology
The traditional name Deneb Kaitos is Arabic ألضنب ألقيتوس ألجنوب - Al Dhanab al Ḳaiṭos al Janūbīyy for "southern tail of Cetus"; it is also known as Diphda, "frog", from the Arabic الضفدع الثاني aḍ-ḍafdaʿ aṯ-ṯānī "the second frog" ("the first frog" is FomalhautFomalhaut
Fomalhaut is the brightest star in the constellation Piscis Austrinus and one of the brightest stars in the sky. Fomalhaut can be seen low in the southern sky in the northern hemisphere in fall and early winter evenings. Near latitude 50˚N, it sets around the time Sirius rises, and does not...
).
In Chinese astronomy
Chinese astronomy
Astronomy in China has a very long history, with historians considering that "they [the Chinese] were the most persistent and accurate observers of celestial phenomena anywhere in the world before the Arabs."...
, Deneb Kaitos is called 土司空, Pinyin
Pinyin
Pinyin is the official system to transcribe Chinese characters into the Roman alphabet in China, Malaysia, Singapore and Taiwan. It is also often used to teach Mandarin Chinese and spell Chinese names in foreign publications and used as an input method to enter Chinese characters into...
: Tǔsīkōng, meaning Master of Constructions, because this star is marking itself and stand alone in Master of Constructions asterism, Legs
Legs (Chinese constellation)
The Legs mansion is one of the Twenty-eight mansions of the Chinese constellations. It is one of the western mansions of the White Tiger.-Asterisms:...
mansion (see : Chinese constellation
Chinese constellation
Chinese constellations are the way the ancient Chinese grouped the stars. They are very different from the modern IAU recognized constellations. This is because the IAU was based on Greco-Roman astronomy instead of Chinese astronomy....
). 土司空 (Tǔsīkōng), westernized into Too Sze Kung by R.H. Allen and the meaning is "Superintendent of Earthworks."
See also
- Lists of stars in the constellation CetusCetusCetus is a constellation. Its name refers to Cetus, a sea monster in Greek mythology, although it is often called 'the whale' today. Cetus is located in the region of the sky that contains other water-related constellations such as Aquarius, Pisces, and Eridanus.-Ecliptic:Although Cetus is not...
- Class K Stars
- Giant starGiant starA giant star is a star with substantially larger radius and luminosity than a main sequence star of the same surface temperature. Typically, giant stars have radii between 10 and 100 solar radii and luminosities between 10 and 1,000 times that of the Sun. Stars still more luminous than giants are...
External links
- Jim Kaler's Stars, University of Illinois: DENEB KAITOS (Beta Ceti)
- Beta Ceti: Giant Star's Corona Brightens with Age