Pi Aurigae on:
[Wikipedia]
[Google]
[Amazon]
Pi Aurigae, Latinized from π Aurigae, is the
HR 2091
Image Pi Aurigae
{{DEFAULTSORT:Pi Aurigae M-type bright giants Asymptotic-giant-branch stars Slow irregular variables Auriga (constellation) Aurigae, Pi BD+45 1217 Aurigae, 35 040239 028404
Pi Aurigae, Latinized from π Aurigae, is the 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. ...
for a single, red-hued 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 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 ...
of Auriga
AURIGA (''Antenna Ultracriogenica Risonante per l'Indagine Gravitazionale Astronomica'') is an ultracryogenic resonant bar gravitational wave detector in Italy. It is at the Laboratori Nazionali di Legnaro of the Istituto Nazionale di Fisica Nuclea ...
. Located about one degree north of the 2nd magnitude star Beta Aurigae
Beta Aurigae (Latinized from β Aurigae, abbreviated Beta Aur, β Aur), officially named Menkalinan , is a binary star system in the northern constellation of Auriga. The combined apparent visual magnitude of the system is 1.9, making it ...
, Pi Aurigae is visible to the naked eye with an apparent visual magnitude of 4.25 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, it is approximately away from Earth. At that distance, the brightness of the star is diminished by 0.54 in magnitude from extinction
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...
caused by interstellar gas and dust.
Pi Aurigae 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 ...
bright giant
A giant star is a star with substantially larger radius and luminosity than a main-sequence (or ''dwarf'') star of the same surface temperature.Giant star, entry in ''Astronomy Encyclopedia'', ed. Patrick Moore, New York: Oxford University Press ...
star 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 M3 II. After exhausting the supply of hydrogen at its core the star has expanded to approximately 127 times the girth of the Sun. It is classified as a slow irregular variable of type LC and its brightness varies from magnitude +4.24 to +4.34. On average, the star is radiating 6,493 times the Sun's luminosity from its enlarged 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 3,388 K.
References
External links
HR 2091
Image Pi Aurigae
{{DEFAULTSORT:Pi Aurigae M-type bright giants Asymptotic-giant-branch stars Slow irregular variables Auriga (constellation) Aurigae, Pi BD+45 1217 Aurigae, 35 040239 028404
2091
In contemporary history, the third millennium of the anno Domini or Common Era in the Gregorian calendar is the current millennium spanning the years 2001 to 3000 ( 21st to 30th centuries). Ongoing futures studies seek to understand what is l ...