20 Tauri
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Maia , designated 20 Tauri (abbreviated 20 Tau), is a star in the constellation of
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 ...
. It is a
blue giant In astronomy, a blue giant is a hot star with a luminosity class of III (giant) or II (bright giant). In the standard Hertzsprung–Russell diagram, these stars lie above and to the right of the main sequence. The term applies to a variety ...
of
spectral type 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 ...
B8 III, a
chemically peculiar star In astrophysics, chemically peculiar stars (CP stars) are stars with distinctly unusual metal abundances, at least in their surface layers. Classification Chemically peculiar stars are common among hot main-sequence (hydrogen-burning) stars. Thes ...
, and the prototype of the Maia variable class of variable star. Maia is the fourth-brightest star in the
Pleiades The Pleiades (), also known as The Seven Sisters, Messier 45 and other names by different cultures, is an asterism and an open star cluster containing middle-aged, hot B-type stars in the north-west of the constellation Taurus. At a distance ...
open star 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 ...
(Messier 45), after Alcyone,
Atlas An atlas is a collection of maps; it is typically a bundle of maps of Earth or of a region of Earth. Atlases have traditionally been bound into book form, but today many atlases are in multimedia formats. In addition to presenting geograp ...
and Electra. It is surrounded by one of the brighter reflection nebulae within the Pleiades, designated NGC 1432 and sometimes called the Maia Nebula.


Nomenclature

The name ''Maia'' originates with the el, Μαῖα and la, Maia.
Maia Maia (; Ancient Greek: Μαῖα; also spelled Maie, ; la, Maia), in ancient Greek religion and mythology, is one of the Pleiades and the mother of Hermes, one of the major Greek gods, by Zeus, the king of Olympus. Family Maia is the daugh ...
is one of the seven daughters of
Atlas An atlas is a collection of maps; it is typically a bundle of maps of Earth or of a region of Earth. Atlases have traditionally been bound into book form, but today many atlases are in multimedia formats. In addition to presenting geograp ...
and Pleione in
Greek mythology A major branch of classical mythology, Greek mythology is the body of myths originally told by the ancient Greeks, and a genre of Ancient Greek folklore. These stories concern the origin and nature of the world, the lives and activities ...
—stars which are also included in the Pleiades star cluster. 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 catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included ''Maia'' for this star. It is now so entered in the IAU Catalog of Star Names. ''20 Tauri'' 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 modern constellations visible from southern England. They are named for John Flamsteed who first used them while co ...
. Although it is about the 15th brightest star in Taurus, Maia does not have a Bayer designation, but does have the
Bright Star Catalogue The Bright Star Catalogue, also known as the Yale Catalogue of Bright Stars, Yale Bright Star Catalogue, or just YBS, is a star catalogue that lists all stars of stellar magnitude 6.5 or brighter, which is roughly every star visible to the nak ...
designation HR 1149 and the Henry Draper Catalogue designation HD 23408. It has been listed as double star WDS J03458+2422; one companion is a 14th magnitude star nearly away that is probably an unrelated background object. The primary is listed as being double following observations of a
lunar occultation An occultation is an event that occurs when one object is hidden from the observer by another object that passes between them. The term is often used in astronomy, but can also refer to any situation in which an object in the foreground blocks ...
, but later observations have failed to find any evidence of it being double.


Description

The distance to Maia has been measured by the
Gaia spacecraft ''Gaia'' is a space observatory of the European Space Agency (ESA), launched in 2013 and expected to operate until 2025. The spacecraft is designed for astrometry: measuring the positions, distances and motions of stars with unprecedented preci ...
using the annual parallax method. In
Gaia Data Release 2 The ''Gaia'' catalogues are star catalogues created using the results obtained by '' Gaia'' space telescope. The catalogues are released in stages that will contain increasing amounts of information; the early releases also miss some stars, espec ...
, the parallax is given as , corresponding to a distance of . The 2007 new Hipparcos reduction gives a statistically more accurate parallax of , indicating a distance of . Analysis of Gaia parallaxes for the whole Pleiades cluster give an average distance of , while
VLBI Very-long-baseline interferometry (VLBI) is a type of astronomical interferometry used in radio astronomy. In VLBI a signal from an astronomical radio source, such as a quasar, is collected at multiple radio telescopes on Earth or in space. T ...
measurements of multiple members give a distance of . Maia's
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 ...
is 3.87, requiring darker skies to be seen. Its
bolometric A bolometer is a device for measuring radiant heat by means of a material having a temperature-dependent electrical resistance. It was invented in 1878 by the American astronomer Samuel Pierpont Langley. Principle of operation A bolometer ...
luminosity is 501 times solar, mostly in the
ultraviolet Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30  PHz) to 400 nm (750  THz), shorter than that of visible light, but longer than X-rays. UV radiation ...
, thus suggesting a radius that is 3.6 times that of the Sun and a mass that is 3.8 times solar. Interferometric measurements give an angular diameter of , suggesting a radius of assuming a distance of . These measurements also allow the effective temperature to be estimated at . Maia is a
chemically peculiar star In astrophysics, chemically peculiar stars (CP stars) are stars with distinctly unusual metal abundances, at least in their surface layers. Classification Chemically peculiar stars are common among hot main-sequence (hydrogen-burning) stars. Thes ...
, meaning it has an unusual surface abundance of some elements as shown by its
spectral lines A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from emission or absorption of light in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used to iden ...
. It is classified as a
helium-weak star Helium-weak stars are chemically peculiar stars which have a weak helium lines for their spectral type. Their helium lines place them in a later (i.e. cooler) spectral type then their hydrogen lines. List of helium-weak stars This is a non-exte ...
, but it also shows an excess of some elements including manganese. Maia was thought to be a
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 e ...
by astronomer
Otto Struve Otto Struve (August 12, 1897 – April 6, 1963) was a Russian-American astronomer of Baltic German origins. In Russian, his name is sometimes given as Otto Lyudvigovich Struve (Отто Людвигович Струве); however, he spent most o ...
. He proposed a class of stars known as Maia variables, which included
Gamma Ursae Minoris Gamma Ursae Minoris (γ Ursae Minoris, abbreviated Gamma UMi, γ UMi), also named Pherkad , is a star in the northern constellation of Ursa Minor. Together with Beta Ursae Minoris (Kochab), it forms the end of the dipper pan of the "Litt ...
. Examination of the '' Hipparcos'' data for Maia and some others in the class found no evidence of variability. On the other hand, White ''et al.'' found low amplitude, but unambiguous, variability in Maia's brightness as seen by ''Kepler''/K2, with a period of 10.3 days, which they attribute to the rotation of a
starspot Starspots are stellar phenomena, so-named by analogy with sunspots. Spots as small as sunspots have not been detected on other stars, as they would cause undetectably small fluctuations in brightness. The commonly observed starspots are in gene ...
. Intense study of large numbers of stars suggest that 6.7% of stars with temperatures between and show rapid small-amplitude pulsations but are not members of other variable star classes. These are potentially Maia variables. Ironically, if the White ''et al.'' results are correct, Maia is a variable star, but not a ''Maia'' variable star. Maia is surrounded by the Maia Nebula (also known as NGC 1432), a reflection nebula that is one of the brightest patches of nebulosity within the Pleiades star cluster. It is the only member of the New General Catalogue discovered photographically.


Mythology

Maia was the oldest of seven beautiful sisters known as the
Pleiades The Pleiades (), also known as The Seven Sisters, Messier 45 and other names by different cultures, is an asterism and an open star cluster containing middle-aged, hot B-type stars in the north-west of the constellation Taurus. At a distance ...
. She was impregnated by Zeus, thereby conceiving Hermes, the messenger god. As Maia and the Pleiades are visible in the winter night sky along with the constellation Orion, the Greek
myths Myth is a folklore genre consisting of Narrative, narratives that play a fundamental role in a society, such as foundational tales or Origin myth, origin myths. Since "myth" is widely used to imply that a story is not Objectivity (philosophy), ...
tell of Maia and her sisters being pursued by the giant huntsman and turned into doves to preserve their safety.
Hesiod Hesiod (; grc-gre, Ἡσίοδος ''Hēsíodos'') was an ancient Greek poet generally thought to have been active between 750 and 650 BC, around the same time as Homer. He is generally regarded by western authors as 'the first written poet ...
, ''Works and Days'' 619ff.


References


External links

*Jim Kaler's Stars, University of Illinoi
Maia (20 Tauri)
*High-resolution LRGB image based on 4 hrs total exposure

*
APOD Astronomy Picture of the Day (APOD) is a website provided by NASA and Michigan Technological University (MTU). According to the website, "Each day a different image or photograph of our universe is featured, along with a brief explanation written ...
Pictures: **1
Orion, the giant huntsman, in pursuit of the Pleiades
**2

**3

{{DEFAULTSORT:Maia (Star) B-type giants Tauri, 020 Pleiades Open Cluster Taurus (constellation)
Maia Maia (; Ancient Greek: Μαῖα; also spelled Maie, ; la, Maia), in ancient Greek religion and mythology, is one of the Pleiades and the mother of Hermes, one of the major Greek gods, by Zeus, the king of Olympus. Family Maia is the daugh ...
Suspected variables 1149 023408 017573 Durchmusterung objects NGC objects