Zeta Persei (ζ Per, ζ Persei) is a
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 a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object.
The origins of the earliest constellation ...
of
Perseus
In Greek mythology, Perseus ( /ˈpɜːrsiəs, -sjuːs/; Greek: Περσεύς, translit. Perseús) is the legendary founder of Mycenae and of the Perseid dynasty. He was, alongside Cadmus and Bellerophon, the greatest Greek hero and slayer ...
. With an
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 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 lines of sight and is measured by the angle or semi-angle of inclination between those two lines. Due to foreshortening, nearby object ...
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 harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's sur ...
.[
]
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 temperature range of supergiant stars spa ...
star 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 the ...
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.][ 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 (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 colors ...
displays anomalously high levels of carbon.[ Zeta Persei has a strong ]stellar wind
A stellar wind is a flow of gas ejected from the 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 spherically symmetric.
...
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 \theta (also known as angular separation, apparent distance, or apparent separation) is the angle between the two sightlines, or between two point objects as viewed from an observer.
Angular distance appears in mathematics (in par ...
of 12.9 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 n ...
s. The two stars have the same proper motion
Proper motion is the astrometric measure of the observed changes in the apparent places of stars or other celestial objects in the sky, as seen from the center of mass of the Solar System, compared to the abstract background of the more distan ...
, so they may be physically associated. If so, they are separated by at least 4,000 Astronomical Unit
The astronomical unit (symbol: au, or or AU) is a unit of length, roughly the distance from Earth to the Sun and approximately equal to or 8.3 light-minutes. The actual distance from Earth to the Sun varies by about 3% as Earth orbits ...
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 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, the density and size of which permit absorption nebulae, the formation of molecules (most commonly molecular hydroge ...
and are about the same age.[
]
Ambiguity
Some sources, including Starry Night (planetarium software)
''The Starry Night'' ( nl, De sterrennacht) is an 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 window of his Lunatic asylum, a ...
, 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) fr ...
.
See also
* HD 121228 - Same spectral class
References
External links
*
{{DEFAULTSORT:Zeta Persei
Persei, Zeta
Perseus (constellation)
B-type supergiants
Atik
Persei, 44
018246
1203
Year 1203 ( MCCIII) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar. It was also the first year to have all digits different from each other since 1098.
Events
By place
Fourth Crusad ...
024398
Durchmusterung objects