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. T ...
for an unconfirmed
binary star
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 ...
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 +4.88. 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 object ...
shift of as seen from Earth, is located 157
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 101 ...
s from the Sun.
This is an
A-type main-sequence star
An A-type main-sequence star (A V) or A dwarf star is a main-sequence (hydrogen-burning) star of spectral type A and luminosity class V (five). These stars have spectra defined by strong hydrogen Balmer absorption lines. They measure between ...
with a
stellar classification
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 t ...
of A4 Vm; the 'm' suffix indicating that abnormal abundances of heavier elements appear in the star's
spectrum
A spectrum (plural ''spectra'' or ''spectrums'') is a condition that is not limited to a specific set of values but can vary, without gaps, across a continuum. The word was first used scientifically in optics to describe the rainbow of color ...
, making this an
Am star An Am star or metallic-line star is a type of chemically peculiar star of spectral type A whose spectrum has strong and often variable absorption lines of metals such as zinc, strontium, zirconium, and barium, and deficiencies of others, such as c ...
. It is 560
million years
The abbreviation Myr, "million years", is a unit of a quantity of (i.e. ) years, or 31.556926 teraseconds.
Usage
Myr (million years) is in common use in fields such as Earth science and cosmology. Myr is also used with Mya (million years ago). ...
old with a
projected rotational velocity
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.
The rotation of a star produces an equatorial bulge ...
of . It has double 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 of ...
and is radiating 23 times the
Sun's 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 nomi ...
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 .
A very close companion has been reported using speckle interferometry, but this remains unconfirmed. The separation at discovery in 1986 was and it was measured at in 1999. It was catalogued by ''
Hipparcos
''Hipparcos'' was a scientific satellite of the European Space Agency (ESA), launched in 1989 and operated until 1993. It was the first space experiment devoted to precision astrometry, the accurate measurement of the positions of celestial obj ...
'' as a problem binary, indicating that the measurements of its position were not consistent with the motion of a single star, but no satisfactory orbit could be found to match the motion
Name
This star, along with λ Aur and ρ Aur, were Kazwini's ''Al Ḣibāʽ'' (ألحباع), the Tent. According to the catalogue of stars in the ''Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars'', ''Al Ḣibāʽ'' were the title for three stars: λ Aur as ''Al Ḣibāʽ I'', μ Aur as ''Al Ḣibāʽ II'' and σ Aur as ''Al Ḣibāʽ III''.
In Chinese, (), meaning '' Celestial Pier'', refers to an asterism consisting of μ Aurigae,
19 Aurigae
19 Aurigae is a single star located approximately 3,800 light years away from the Sun in the northern constellation Auriga. It is visible to the naked eye as a faint, white-hued star with an apparent visual magnitude of 5.05. The st ...
,
φ Aurigae
Phi Aurigae, Latinized from φ Aurigae, is a giant star in the northern constellation of Auriga. It is faintly visible to the naked eye with an apparent visual magnitude of 5.089. It lies from another faint naked-eye star HD 35520, ...
,
14 Aurigae
14 Aurigae is a quadruple star system located 269 light years away from the Sun in the zodiac constellation of Auriga. It has the variable star designation KW Aurigae, whereas ''14 Aurigae'' is the Flamsteed designation. It is visib ...
and
σ Aurigae
Sigma Aurigae, Latinized from σ Aurigae, is a giant star in the northern constellation of Auriga. It is faintly visible to the naked eye with an apparent visual magnitude of 4.99. With an annual parallax shift of 6.21 mas, it is ...
1689
Events
January–March
* January 22 (January 12, 1688 O.S.) – Glorious Revolution in England: The Convention Parliament is convened to determine if King James II of England, the last Roman Catholic British monarch, vacated ...