Theta Tauri (θ Tauri, abbreviated Theta Tau, θ Tau) is a wide

double star In observational astronomy, a double star or visual double is a pair of stars that appear close to each other as viewed from Earth, especially with the aid of optical telescopes. This occurs because the pair either forms a binary star (i.e. a bi ...

in the

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 origins of the e ...

Taurus Taurus is Latin for 'bull' and may refer to: * Taurus (astrology), the astrological sign * Taurus (constellation), one of the constellations of the zodiac * Taurus (mythology), one of two Greek mythological characters named Taurus * '' Bos tauru ...

and a member of the

Hyades Hyades may refer to: * Hyades (band) *Hyades (mythology) *Hyades (star cluster) The Hyades (; Greek Ὑάδες, also known as Caldwell 41, Collinder 50, or Melotte 25) is the nearest open cluster and one of the best-studied star clusters. Loca ...

open cluster An open cluster is a type of star cluster made of up to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way galaxy, and ...

. θ Tauri is composed of two 3rd

magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its magnitude and its direction *Magnitude (mathematics), the relative size of an object *Norm (mathematics), a term for the size or length of a vector *Order of ...

stars, designated Theta Tauri (Theta Tauri B) and Theta Tauri (Theta Tauri A). Theta² is brighter, hence the pair are sometimes referred to as Theta Tauri B and A, respectively. They are separated by 5.62

arcminute A minute of arc, arcminute (arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of one degree. Since one degree is of a turn (or complete rotation), one minute of arc is of a turn. The na ...

s (0.094°) on the sky. Based upon

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 ...

measurements, Theta¹ Tauri is located at a distance of , while Theta² Tauri is at a distance of . θ Tauri A and B are both

spectroscopic binaries A binary star is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separate stars, in wh ...

; the four components are designated Theta Tauri Aa (formally named Chamukuy ), Ab, Ba, and Bb.

Nomenclature

''θ Tauri'' ( Latinised to ''Theta Tauri'') is the double 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. ...

; θ Tauri and θ Tauri those of its two constituents. The designations of the two constituents as ''Theta Tauri A'' and ''B'', and those of the four components - ''Theta Tauri Aa'', ''Ab'', ''Ba'' and ''Bb'' - derive from the convention used by the Washington Multiplicity Catalog (WMC) for

multiple star system A star system or stellar system is a small number of stars that orbit each other, bound by gravitational attraction. A large group of stars bound by gravitation is generally called a '' star cluster'' or '' galaxy'', although, broadly speaki ...

s, and adopted by 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 ...

(IAU). In the

mythology Myth is a folklore genre consisting of narratives that play a fundamental role in a society, such as foundational tales or origin myths. Since "myth" is widely used to imply that a story is not objectively true, the identification of a narrat ...

of the

Maya peoples The Maya peoples () are an ethnolinguistic group of Indigenous peoples of the Americas, indigenous peoples of Mesoamerica. The ancient Maya civilization was formed by members of this group, and today's Maya are generally descended from people ...

, Theta Tauri is known as ''Chamukuy'', meaning a small bird in the

Yucatec Maya language Yucatec Maya (; referred to by its speakers simply as Maya or as , is one of the 32 Mayan languages of the Mayan language family. Yucatec Maya is spoken in the Yucatán Peninsula and northern Belize. There is also a significant diasporic commu ...

. In 2016, the IAU 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 decided to attribute proper names to individual stars rather than entire multiple systems. It approved the name ''Chamukuy'' for the component Theta Tauri Aa on 5 September 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 ...

, (), meaning ''

Net Net or net may refer to: Mathematics and physics * Net (mathematics), a filter-like topological generalization of a sequence * Net, a linear system of divisors of dimension 2 * Net (polyhedron), an arrangement of polygons that can be folded up ...

'', refers to an asterism consisting of Theta² Tauri,

Epsilon Tauri Epsilon Tauri or ε Tauri, formally named Ain (), is an orange giant star located approximately 45 parsecs (147 light-years) from the Sun in the constellation of Taurus. An extrasolar planet (designated Epsilon Tauri b, later named Amat ...

(named Ain), Delta³ Tauri, Delta¹ Tauri,

Gamma Tauri Gamma Tauri (γ Tauri, abbreviated Gamma Tau, γ Tau) is either a solitary, binary star, binary or double star (the Washington Double Star Catalog notes it as a "Dubious Double" or "Bogus Binary") that marks the tip of the "V" in the const ...

, Alpha Tauri (

Aldebaran Aldebaran (Arabic: “The Follower”, "الدبران") is the brightest star in the zodiac constellation of Taurus. It has the Bayer designation α Tauri, which is Latinized to Alpha Tauri and abbreviated Alpha Tau or α Tau. Aldebar ...

), 71 Tauri and

Lambda Tauri Lambda Tauri (λ Tau, λ Tauri) is a triple star system in the constellation Taurus. In the ''Calendarium of Al Achsasi Al Mouakket'', this star was designated ''Sadr al Tauri'', which was translated into Latin as ''Pectus Tauri'', meanin ...

. 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 Theta² Tauri itself is (), "the Sixth Star of Net".

Properties

Theta Tauri A has a mean

apparent 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 li ...

of +3.40. It is classified as a Delta Scuti type

variable star A variable star is a star whose brightness as seen from Earth (its apparent magnitude) changes with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are classified as ...

and its brightness varies from magnitude +3.35 to +3.42 with a period of 1.82 hours. Its primary component, Theta Tauri Aa, is a white A-type

giant In folklore, giants (from Ancient Greek: '' gigas'', cognate giga-) are beings of human-like appearance, but are at times prodigious in size and strength or bear an otherwise notable appearance. The word ''giant'' is first attested in 1297 fr ...

. The secondary, Theta Tauri Ab, is of the 6th magnitude and is 0.005

arcsecond A minute of arc, arcminute (arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of one degree. Since one degree is of a turn (or complete rotation), one minute of arc is of a turn. The na ...

s, or at least 2 AU, distant. It completes an

orbit In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such as a p ...

once every 141 days. Theta Tauri B is the dimmer constituent. Its primary component, Theta Tauri Ba, is an orange K-type

with an

of +3.84. The secondary, Theta Tauri Bb, is of the 7th-magnitude. It has a mass of and orbits the primary every 16.26 years on a fairly eccentric (at 0.570) orbit.

References

External links

Observing Naked-eye Stars
{{DEFAULTSORT:Theta Tauri Tauri, Theta Taurus (constellation) 4 Delta Scuti variables Spectroscopic binaries G-type giants A-type giants Hyades (star cluster) Tauri, 77 8 020885 94 028307 19 1411 2 BD+15 0631