Zeta Persei (ζ Per, ζ Persei) is a

star A star is a luminous spheroid of plasma (physics), plasma held together by Self-gravitation, self-gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night sk ...

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 first constellati ...

Perseus In Greek mythology, Perseus (, ; Greek language, Greek: Περσεύς, Romanization of Greek, translit. Perseús) is the legendary founder of the Perseid dynasty. He was, alongside Cadmus and Bellerophon, the greatest Greek hero and slayer of ...

. With an

apparent visual magnitude Apparent magnitude () is a measure of the brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction of the object's light ca ...

of 2.9, it can be readily seen with the naked eye.

Parallax Parallax is a displacement or difference in the apparent position of an object viewed along two different sightline, lines of sight and is measured by the angle or half-angle of inclination between those two lines. Due to perspective (graphica ...

measurements place it at a distance of about from

Earth Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...

, though measurements of its Ca II lines place it at .

Description

This is a lower luminosity

supergiant Supergiants are among the most massive and most luminous stars. Supergiant stars occupy the top region of the Hertzsprung–Russell diagram, with absolute visual magnitudes between about −3 and −8. The temperatures of supergiant stars range ...

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 gratin ...

of B1 Ib. This is an enormous star, with an estimated 26–27 times the Sun's radius and 13–16 times the

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

. It has about 47,000 times the luminosity of the Sun and it is radiating this energy 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 20,800 K, giving it the blue-white hue of a B-type star. The

spectrum A spectrum (: spectra or spectrums) is a set of related ideas, objects, or properties whose features overlap such that they blend to form a continuum. The word ''spectrum'' was first used scientifically in optics to describe the rainbow of co ...

displays anomalously high levels of carbon. Zeta Persei has a strong

stellar wind A stellar wind is a flow of gas ejected from the stellar atmosphere, upper atmosphere of a star. It is distinguished from the bipolar outflows characteristic of young stars by being less collimated, although stellar winds are not generally spheri ...

that is expelling times the mass of the Sun per year, or the equivalent of the Sun's mass every 4.3 million years. Zeta Persei has a 9th magnitude companion at an

angular separation Angular distance or angular separation is the measure of the angle between the orientation of two straight lines, rays, or vectors in three-dimensional space, or the central angle subtended by the radii through two points on a sphere. When t ...

of 12.9

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

s. The two stars have the same

proper motion Proper motion is the astrometric measure of changes in the apparent places of stars or other celestial objects as they move relative to the center of mass of the Solar System. It is measured relative to the distant stars or a stable referenc ...

, so they may be physically associated. If so, they are separated by at least 4,000

Astronomical Unit The astronomical unit (symbol: au or AU) is a unit of length defined to be exactly equal to . Historically, the astronomical unit was conceived as the average Earth-Sun distance (the average of Earth's aphelion and perihelion), before its m ...

s. Zeta Persei is a confirmed member of the Perseus OB2 association (Per OB2), also called the Zeta Persei association, which is a

moving group In astronomy, stellar kinematics is the observational study or measurement of the kinematics or motions of stars through space. Stellar kinematics encompasses the measurement of stellar velocities in the Milky Way and its satellites as well as ...

of stars that includes 17 massive, high luminosity members with spectral types of O or B, giving them a blue hue. These stars have a similar trajectory through space, suggesting they originated in the same

molecular cloud A molecular cloud—sometimes called a stellar nursery if star formation is occurring within—is a type of interstellar cloud of which the density and size permit absorption nebulae, the formation of molecules (most commonly molecular hydrogen, ...

and are about the same age.

Ambiguity

Some sources, including

Starry Night (planetarium software) ''The Starry Night'', often called simply ''Starry Night'', is an Oil painting, oil-on-canvas painting by the Dutch Post-Impressionism, Post-Impressionist painter Vincent van Gogh. Painted in June 1889, it depicts the view from the east-facing w ...

, an atlas, and a web siteYour Sky Object Catalogue: Named Stars
/ref> attribute the name 'Atik' to Zeta Persei instead of nearby

Omicron Persei Omicron Persei (ο Persei, abbreviated Omicron Per, ο Per) is a triple star system in the constellation of Perseus. From parallax measurements taken during the Hipparcos mission it is approximately 1,100 light-years (330 parsecs) from ...

References

External links

* {{DEFAULTSORT:Zeta Persei B-type supergiants Perseus (constellation) Persei, Zeta Durchmusterung objects Persei, 44 024398 018246

1203 Year 1203 ( MCCIII) was a common year starting on Wednesday of the Julian calendar. It was also the first year to have all digits different from each other since 1098. Events By place Fourth Crusade * April 20 – The Crusader arm ...

Atik

Description

Ambiguity

See also

References

External links