39 Arietis (abbreviated 39 Ari), officially named Lilii Borea ,
is a
star
A star is a luminous spheroid of plasma (physics), plasma held together by Self-gravitation, self-gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night sk ...
in the northern
constellation
A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object.
The first constellati ...
of
Aries
Aries may refer to:
*Aries (astrology), an astrological sign
*Aries (constellation), a constellation in the zodiac
Arts, entertainment and media
* ''Aries'' (album), by Luis Miguel, 1993
* ''Aries'' (EP), by Alice Chater, 2020
* "Aries" (song), ...
. It is visible to the naked eye with an
apparent visual magnitude
Apparent magnitude () is a measure of the brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction of the object's light ca ...
of +4.5.
[ The distance to this star, as determined from an annual ]parallax
Parallax is a displacement or difference in the apparent position of an object viewed along two different sightline, lines of sight and is measured by the angle or half-angle of inclination between those two lines. Due to perspective (graphica ...
shift of 19.01 mas,[ is approximately .
This star was formerly located in the obsolete constellation Musca Borealis.]
Nomenclature
''39 Arietis'' is the star's Flamsteed designation
A Flamsteed designation is a combination of a number and constellation name that uniquely identifies most naked eye stars in the 88 modern constellations, modern constellations visible from southern England. They are named after John Flamsteed, au ...
.
This star was described as ''Lilii Borea'' by Nicolas-Louis de Lacaille
Abbé Nicolas-Louis de Lacaille (; 15 March 171321 March 1762), formerly sometimes spelled de la Caille, was a kingdom of France, French astronomer and geodesist who named 14 out of the IAU designated constellations, 88 constellations. From 1750 ...
in 1757,
as a star of the now-defunct constellation of Lilium
''Lilium'' ( ) is a genus of Herbaceous plant, herbaceous flowering plants growing from bulbs, all with large and often prominent flowers. Lilies are a group of flowering plants which are important in culture and literature in much of the world ...
(the Lily
''Lilium'' ( ) is a genus of herbaceous flowering plants growing from bulbs, all with large and often prominent flowers. Lilies are a group of flowering plants which are important in culture and literature in much of the world. Most species are ...
). The words are simply the Latin phrase ''Līliī Boreā'' 'in the north of Lilium'. ''Līliī Austrīnā'' 'in the south of Lilium' was 41 Arietis
41 Arietis (abbreviated 41 Ari) is a triple star system in the northern constellation of Aries. With an apparent visual magnitude of 3.63, this system is readily visible to the naked eye. It has an annual parallax shift of 19.69 m ...
.
In 2016, the International Astronomical Union
The International Astronomical Union (IAU; , UAI) is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and developmen ...
organized a Working Group on Star Names
The International Astronomical Union (IAU) established a Working Group on Star Names (WGSN) in May 2016 to catalog and standardize proper names for stars for the international astronomical community. It operates under Division C – Education ...
(WGSN) to catalog and standardize proper names for stars. The WGSN approved the name ''Lilii Borea'' for this star on 5 September 2017 and it is now so included in the List of IAU-approved Star Names.
In Chinese
Chinese may refer to:
* Something related to China
* Chinese people, people identified with China, through nationality, citizenship, and/or ethnicity
**Han Chinese, East Asian ethnic group native to China.
**'' Zhonghua minzu'', the supra-ethnic ...
, (), meaning ''Stomach
The stomach is a muscular, hollow organ in the upper gastrointestinal tract of Human, humans and many other animals, including several invertebrates. The Ancient Greek name for the stomach is ''gaster'' which is used as ''gastric'' in medical t ...
'', refers to an asterism consisting of 39 Arietis, 35 Arietis
35 Arietis (abbreviated 35 Ari) is a binary star in the northern constellation of Aries. ''35 Arietis'' is the Flamsteed designation. It is approximately distant from the Earth, based upon an annual parallax shift of 9.51 mas. This ...
and 41 Arietis
41 Arietis (abbreviated 41 Ari) is a triple star system in the northern constellation of Aries. With an apparent visual magnitude of 3.63, this system is readily visible to the naked eye. It has an annual parallax shift of 19.69 m ...
. Consequently, the Chinese name
Chinese may refer to:
* Something related to China
* Chinese people, people identified with China, through nationality, citizenship, and/or ethnicity
**Han Chinese, East Asian ethnic group native to China.
**'' Zhonghua minzu'', the supra-ethni ...
for 39 Arietis itself is (, ).[ 白羊座]
Properties
39 Arietis is a giant star
A giant star has a substantially larger radius and luminosity than a main-sequence (or ''dwarf'') star of the same surface temperature. They lie above the main sequence (luminosity class V in the Yerkes spectral classification) on the Hertzsp ...
with a stellar classification
In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction gratin ...
of K1.5 III.[ It is currently at an evolutionary stage known as the ]red clump
The red clump is a clustering of red giants in the Hertzsprung–Russell diagram at around 5,000 K and absolute magnitude (MV) +0.5, slightly hotter than most red-giant-branch stars of the same luminosity. It is visible as a denser region of ...
, indicating that it is generating energy through the fusion of helium
Helium (from ) is a chemical element; it has chemical symbol, symbol He and atomic number 2. It is a colorless, odorless, non-toxic, inert gas, inert, monatomic gas and the first in the noble gas group in the periodic table. Its boiling point is ...
at its core.[ It has 1.6][ times the ]mass of the Sun
The solar mass () is a frequently used unit of mass in astronomy, equal to approximately . It is approximately equal to the mass of the Sun. It is often used to indicate the masses of other stars, as well as stellar clusters, nebulae, galaxies a ...
, but its outer envelope has expanded to around 10 times the Sun's radius
Solar radius is a unit of distance used to express the size of objects in astronomy relative to the Sun. The solar radius is usually defined as the radius to the layer in the Sun's photosphere where the optical depth equals 2/3:
1\,R_ = 6.957\ti ...
. It shines with 49 times the luminosity of the Sun
The solar luminosity () is a unit of radiant flux ( power emitted in the form of photons) conventionally used by astronomers to measure the luminosity of stars, galaxies and other celestial objects in terms of the output of the Sun.
One nominal s ...
. This energy is being radiated into outer space from its outer atmosphere at an effective temperature
The effective temperature of a body such as a star or planet is the temperature of a black body that would emit the same total amount of electromagnetic radiation. Effective temperature is often used as an estimate of a body's surface temperature ...
of 4,768 K,[ giving it the cool orange-hued glow of a ]K-type star
In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting the ...
.[
]
See also
* Aries (Chinese astronomy)
References
External links
Aladin previewer
Aladin sky atlas
HR 824
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K-type giants
Horizontal-branch stars
Aries (constellation)
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Lilii Borea