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
zodiac
The zodiac is a belt-shaped region of the sky that extends approximately 8° north or south (as measured in celestial latitude) of the ecliptic, the Sun path, apparent path of the Sun across the celestial sphere over the course of the year. ...
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
Taurus
Taurus is Latin for 'bull' and may refer to:
* Taurus (astrology), the astrological sign
* Taurus (constellation), one of the constellations of the zodiac
* Taurus (mythology), one of two Greek mythological characters named Taurus
* ''Bos taurus ...
. It has a visual magnitude of 5.64, making it visible to the naked eye from suburban skies (according to the
Bortle scale
The Bortle scale (also known as the Bottle scale) is a nine-level numeric scale that measures the night sky's brightness of a particular location. It quantifies the astronomical observability of celestial objects and the interference caused by lig ...
). The position of this star near the
ecliptic plane
The ecliptic or ecliptic plane is the orbital plane of the Earth around the Sun. From the perspective of an observer on Earth, the Sun's movement around the celestial sphere over the course of a year traces out a path along the ecliptic again ...
means that it is subject to
occultation
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 ...
s by the
Moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...
.
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 put it at a distance of 144
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 1012 ...
s from the Sun. It 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 +31.9 km/s, having come to within some 759,000 years ago.
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 i ...
of this star matches 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 F2IVs, with the luminosity class of IV indicating that this star has reached the subgiant stage and is in the process of evolving into a giant star. It has twice the mass of the sun with nearly three times the Sun's radius, but 15 times the Sun's luminosity and about half the Sun's age. The abundance of elements other than hydrogen and helium is lower in this star than in the Sun. The
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 the star's outer atmosphere is , giving it the white-hued glow of an F-type star.
1218
Year 1218 ( MCCXVIII) was a common year starting on Monday (link will display the full calendar) of the Julian calendar.
Events
By place
Fifth Crusade
* May 24 – A Crusader expeditionary force, (some 30,000 men) under King Joh ...