Lambda Draconis (λ Draconis, abbreviated Lam Dra, λ Dra), also named Giausar ( ), is a solitary, orange-red

star A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked ...

in the northern

circumpolar constellation A circumpolar star is a star that, as viewed from a given latitude on Earth, never sets below the horizon due to its apparent proximity to one of the celestial poles. Circumpolar stars are therefore visible from said location toward the nearest po ...

Draco Draco is the Latin word for serpent or dragon. Draco or Drako may also refer to: People * Draco (lawgiver) (from Greek: Δράκων; 7th century BC), the first lawgiver of ancient Athens, Greece, from whom the term ''draconian'' is derived * D ...

. It is visible to the naked eye with an

apparent visual magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's lig ...

of +3.85. Based upon an annual

parallax Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight and is measured by the angle or semi-angle of inclination between those two lines. Due to foreshortening, nearby objects ...

shift of 9.79

mas Mas, Más or MAS may refer to: Film and TV * Más y Menos, fictional superhero characters, from the Teen Titans animated television series * Más (Breaking Bad), "Más" (''Breaking Bad''), a season three episode of ''Breaking Bad'' Songs * Más ( ...

as seen from the Earth, the star is located around 333

light year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

s from the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

. This is an

evolved Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation t ...

red giant A red giant is a luminous giant star of low or intermediate mass (roughly 0.3–8 solar masses ()) in a late phase of stellar evolution. The outer atmosphere is inflated and tenuous, making the radius large and the surface temperature around or ...

star on the

asymptotic giant branch The asymptotic giant branch (AGB) is a region of the Hertzsprung–Russell diagram populated by evolved cool luminous stars. This is a period of stellar evolution undertaken by all low- to intermediate-mass stars (about 0.5 to 8 solar masses) lat ...

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 grati ...

of M0III-IIIa Ca1. It is a suspected

slow irregular variable A slow irregular variable (ascribed the GCVS types L, LB and LC) is a variable star that exhibit no or very poorly defined periodicity in their slowly changing light emissions. These stars have often been little-studied, and once more is learnt abo ...

with a periodicity of roughly 1,100 days. The measured

angular diameter The angular diameter, angular size, apparent diameter, or apparent size is an angular distance describing how large a sphere or circle appears from a given point of view. In the vision sciences, it is called the visual angle, and in optics, it is ...

, after correction for

limb darkening Limb darkening is an optical effect seen in stars (including the Sun), where the central part of the disk appears brighter than the edge, or ''limb''. Its understanding offered early solar astronomers an opportunity to construct models with such ...

, is . At the estimated distance of the star, this yields a physical size of about 53 times the

radius of the Sun Solar radius is a unit of distance used to express the size of stars 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\t ...

. It has an estimated 1.7 times the

mass of the Sun The solar mass () is a standard unit of mass in astronomy, equal to approximately . It is often used to indicate the masses of other stars, as well as stellar clusters, nebulae, galaxies and black holes. It is approximately equal to the mass ...

and is radiating 834 times the

solar luminosity 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 ...

from its

photosphere The photosphere is a star's outer shell from which light is radiated. The term itself is derived from Ancient Greek roots, φῶς, φωτός/''phos, photos'' meaning "light" and σφαῖρα/''sphaira'' meaning "sphere", in reference to it ...

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 3,958 K.

Nomenclature

λ Draconis ( Latinised to ''Lambda Draconis'') is the star's

Bayer designation A Bayer designation is a stellar designation in which a specific star is identified by a Greek or Latin letter followed by the genitive form of its parent constellation's Latin name. The original list of Bayer designations contained 1,564 stars. ...

. It bore the traditional name ''Giausar'' (also written as ''Gianfar, Giansar and Giauzar'') and ''Juza.'' In 2016, the

International Astronomical Union The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreac ...

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 catalogue and standardize proper names for stars. The WGSN approved the name ''Giausar'' for this star on February 1, 2017 and it is now so included in the List of IAU-approved Star Names. In

Chinese Chinese can refer to: * Something related to China * Chinese people, people of Chinese nationality, citizenship, and/or ethnicity **''Zhonghua minzu'', the supra-ethnic concept of the Chinese nation ** List of ethnic groups in China, people of va ...

, (), meaning '' Right Wall of Purple Forbidden Enclosure'', refers to an asterism consisting of Lambda Draconis,

Alpha Draconis Thuban (), with Bayer designation Alpha Draconis or α Draconis, is a binary star system in the northern constellation of Draco. A relatively inconspicuous star in the night sky of the Northern Hemisphere, it is historically significant ...

Kappa Draconis Kappa Draconis, Latinized from κ Draconis, is a blue giant star located in the northern circumpolar constellation of Draco. At an apparent magnitude of 3.88, it is barely visible to the naked eye when artificial lighting from cities ...

24 Ursae Majoris 24 Ursae Majoris is a variable star in the northern circumpolar constellation of Ursa Major, located 101.5 light-years from the Sun. It has the variable star designation DK Ursae Majoris and the Bayer designation d Ursae Majoris; ''2 ...

43 Camelopardalis 43 Camelopardalis is a single star in the northern circumpolar constellation of Camelopardalis, located roughly 1,060 light years away from the Sun based on parallax. It is visible to the naked eye as a faint, blue-white hued star wit ...

Alpha Camelopardalis Alpha Camelopardalis, Latinized from α Camelopardalis, is a star in the northern constellation of Camelopardalis. With an apparent visual magnitude of 4.3, it is the third-brightest star in this not-very-prominent circumpolar constellat ...

and

BK Camelopardalis BK Camelopardalis is a variable star in the northern circumpolar constellation of Camelopardalis, near the constellation border with Cassiopeia. It is visible to the naked eye as a faint, blue-white hued star with an apparent visual magn ...

. Consequently, the

Chinese name Chinese names or Chinese personal names are names used by individuals from Greater China and other parts of the Chinese-speaking world throughout East and Southeast Asia (ESEA). In addition, many names used in Japan, Korea and Vietnam are often a ...

for Lambda Draconis itself is (, en, the Third Star of Right Wall of Purple Forbidden Enclosure.), representing (), meaning ''First Minister''.English-Chinese Glossary of Chinese Star Regions, Asterisms and Star Name
, Hong Kong Space Museum. Accessed on line November 23, 2010. 上輔 (Shǎngfǔ) was westernized into ''Sang Poo'' or ''Shaou Poo'' by R.H. Allen.

Namesakes

USS Giansar (AK-111) was a

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

Crater class cargo ship The ''Crater''-class cargo ship were converted EC2-S-C1 type, Liberty ship, Liberty cargo ships, constructed by the United States Maritime Commission (USMC) for use by the United States Navy, US Navy during World War II. The designation 'EC2-S-C1' ...

named after the star.

References

{{DEFAULTSORT:Lambda Draconis M-type giants Asymptotic-giant-branch stars Semiregular variable stars Suspected variables Draco (constellation) Draconis, Lambda Durchmusterung objects Draconis, 01 100029 056211 4434

Giausar Lambda Draconis (λ Draconis, abbreviated Lam Dra, λ Dra), also named Giausar ( ), is a solitary, orange-red star in the northern circumpolar constellation of Draco (constellation), Draco. It is visible to the naked eye with an apparent v ...