Zeta Cassiopeiae
Encyclopedia
Zeta Cassiopeiae (ζ Cas, ζ Cassiopeiae) is a star
in the constellation
Cassiopeia
. It has a blue-white hue and is classified as a B-type
subgiant with an apparent magnitude
of +3.67. It is approximately 590 light years
from Earth
.
ζ Cas is a member of an unusual group of variable stars known as "Slowing Pulsating B" (SPB) stars. It shows a pulsation frequency of 0.64 per day (or once every 1.56 days) and displays a weak magnetic field with a strength of roughly , which varies with a period of 5.37 days. This likely matches the rotation rate of the star, which, when combined with the low projected rotational velocity
, indicates the star may be seen nearly pole-on. Zeta Cassiopeiae is a candidate magnetic Bp star that shows an overabundance of helium. The star contains a randomly oriented fossil magnetic field
, which impacts the outflow of the stellar wind. Collisions between streams from this stellar wind creates a shock front, with cooling particles settling toward a co-rotating disk.
, Zeta Cassiopeiae is called 附路, Pinyin
: Fùlù, meaning Auxiliary Road, because this star is marking itself and stand alone in Auxiliary Road asterism, Legs
(mansion) (see : Chinese constellation
). 附路 (Fùlù) is westernized into Foo Loo, but the name Foo Loo was designated not only for Zeta Cassiopeiae, but also for η Cassiopeiae
(Achird) by R.H. Allen, with the meaning is "a by-path"
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....
Cassiopeia
Cassiopeia (constellation)
Cassiopeia is a constellation in the northern sky, named after the vain queen Cassiopeia in Greek mythology, who boasted about her unrivalled beauty. Cassiopea was one of the 48 constellations listed by the 2nd century Greek astronomer Ptolemy, and it remains one of the 88 modern constellations today...
. It has a blue-white hue and is classified as a B-type
Stellar 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...
subgiant 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 +3.67. It is approximately 590 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 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...
.
ζ Cas is a member of an unusual group of variable stars known as "Slowing Pulsating B" (SPB) stars. It shows a pulsation frequency of 0.64 per day (or once every 1.56 days) and displays a weak magnetic field with a strength of roughly , which varies with a period of 5.37 days. This likely matches the rotation rate of the star, which, when combined with the low projected rotational velocity
Stellar rotation
Stellar rotation is the angular motion of a star about its axis. The rate of rotation can be measured from the spectrum of the star, or by timing the movements of active features on the surface....
, indicates the star may be seen nearly pole-on. Zeta Cassiopeiae is a candidate magnetic Bp star that shows an overabundance of helium. The star contains a randomly oriented fossil magnetic field
Fossil stellar magnetic field
Fossil stellar magnetic fields or fossil fields are proposed as possible interstellar magnetic fields that became locked into certain stars....
, which impacts the outflow of the stellar wind. Collisions between streams from this stellar wind creates a shock front, with cooling particles settling toward a co-rotating disk.
Chinese name
In Chinese astronomyChinese 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."...
, Zeta Cassiopeiae is called 附路, 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...
: Fùlù, meaning Auxiliary Road, because this star is marking itself and stand alone in Auxiliary Road 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....
). 附路 (Fùlù) is westernized into Foo Loo, but the name Foo Loo was designated not only for Zeta Cassiopeiae, but also for η Cassiopeiae
Eta Cassiopeiae
Eta Cassiopeiae is a star system 19.4 light years away from Earth, in the constellation Cassiopeia. Sometimes the traditional name Achird is used....
(Achird) by R.H. Allen, with the meaning is "a by-path"
See also
- Lists of stars in the constellation Cassiopeiae
- Class B Stars
- Pulsating Variable Stars