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
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
Aries
Aries may refer to:
*Aries (astrology), an astrological sign
*Aries (constellation), a constellation of stars in the zodiac
Arts, entertainment and media
* ''Aries'' (album), by Luis Miguel, 1993
* ''Aries'' (EP), by Alice Chater, 2020
* "Aries" ...
. It has an apparent visual magnitude of +5.52, which is bright enough for the star to be seen with the naked eye from dark suburban skies. The star is located at a distance of approximately from the Sun based on
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 ...
, and is drifting further away with a
radial velocity
The radial velocity or line-of-sight velocity, also known as radial speed or range rate, of a target with respect to an observer is the temporal rate of change, rate of change of the distance or Slant range, range between the two points. It is e ...
of +17 km/s. On November 20, 1952, it was observed being
occulted
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 ...
by the planet
Jupiter
Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but ...
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 B7 V. This is a large star with three times the radius of the Sun and 3.8 times the Sun's mass. It shines around 301 times as brightly as the Sun, with this energy being radiated into space from its outer atmosphere at a scorching hot
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 13,121 K. It is this heat that gives the star the blue-white hue of a
B-type star
A B-type main-sequence star (B V) is a main-sequence (hydrogen-burning) star of spectral type B and luminosity class V. These stars have from 2 to 16 times the mass of the Sun and surface temperatures between 10,000 and 30,000 K. B-type stars ...
. Sigma Arietis is spinning at a rapid clip, 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 165 km/s. It is a probable member of the Cas-Tau
OB association
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 t ...
of stars that share a common motion through space.
In 2016, a stellar companion was reported based on observations using adaptive optics with the
Gemini North Telescope
The Gemini Observatory is an astronomical observatory consisting of two 8.1-metre (26.6 ft) telescopes, Gemini North and Gemini South, which are located at two separate sites in Hawaii and Chile, respectively. The twin Gemini telescopes prov ...