HD 147513 (62 G. Scorpii) is a star in the southern

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 ...

Scorpius Scorpius is a zodiac constellation located in the Southern celestial hemisphere, where it sits near the center of the Milky Way, between Libra to the west and Sagittarius to the east. Scorpius is an ancient constellation that pre-dates the Gre ...

. It was first catalogued by Italian astronomer Piazzi in his

star catalogue A star catalogue is an astronomical catalogue that lists stars. In astronomy, many stars are referred to simply by catalogue numbers. There are a great many different star catalogues which have been produced for different purposes over the years, ...

as "XVI 55". With an

apparent 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 li ...

of 5.38, 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 ...

it is visible to the naked eye from suburban skies. Based upon

stellar parallax Stellar parallax is the apparent shift of position of any nearby star (or other object) against the background of distant objects, and a basis for determining (through trigonometry) the distance of the object. Created by the different orbital p ...

measurements by the

Hipparcos ''Hipparcos'' was a scientific satellite of the European Space Agency (ESA), launched in 1989 and operated until 1993. It was the first space experiment devoted to precision astrometry, the accurate measurement of the positions of celestial obj ...

spacecraft, HD 147513 lies some 42

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.

Properties

This is a

Sun-like Solar-type star, solar analogs (also analogues), and solar twins are stars that are particularly similar to the Sun. The stellar classification is a hierarchy with solar twin being most like the Sun followed by solar analog and then solar-typ ...

main sequence In astronomy, the main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Her ...

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 G1VH-04. It has about 11% greater mass than the Sun, and is considered young with an estimated age of 400 million years. As such, it has a similar luminosity to the Sun despite being more massive. Although the abundance of elements is similar to the Sun, it is a Barium star that is overabundant in elements produced through the

s-process The slow neutron-capture process, or ''s''-process, is a series of reactions in nuclear astrophysics that occur in stars, particularly asymptotic giant branch stars. The ''s''-process is responsible for the creation (nucleosynthesis) of approximat ...

. HD 147513 is suspected of being a

variable star A variable star is a star whose brightness as seen from Earth (its apparent magnitude) changes with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are classified as ...

.NSV 7680 -- Variable Star
- SIMBAD entry HD 147513 is a member of the Ursa Major moving group that share a common

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 dista ...

through space. It has a nearby co-moving companion: a DA-class

white dwarf A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to the Sun's, while its volume is comparable to the Earth's. A white dwarf's faint luminosity comes fro ...

located some 5,360 AU distant, where an AU is the average separation of the Earth from the Sun. At one time the pair may have been members of a multiple star system. The progenitor of the white dwarf may have been a closer companion, and while passing through the

asymptotic giant branch The asymptotic giant branch (AGB) is a region of the Hertzsprung–Russell diagram populated by evolved cool luminous stars. This is a period of stellar evolution undertaken by all low- to intermediate-mass stars (about 0.5 to 8 solar masses) lat ...

stage of its evolution, could have transferred matter onto HD 147513 and contaminated this star's photosphere.

Planetary system

In 2002, the Geneva Extrasolar Planet Search Team announced the discovery of an extrasolar planet orbiting the star. Based upon the orbital elements, most of this gas giant's orbit lies within the habitable zone (HZ) of the host star; it only passes outside this region at

apogee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any ellip ...

. As such, it is unlikely that a

terrestrial planet A terrestrial planet, telluric planet, or rocky planet, is a planet that is composed primarily of silicate rocks or metals. Within the Solar System, the terrestrial planets accepted by the IAU are the inner planets closest to the Sun: Mercury, Ve ...

could have a stable orbit within the HZ unless it moves in a synchronized fashion with the gas giant. Numerical simulations suggest that such a planet could orbit within the L₄ or L₅

Lagrangian point In celestial mechanics, the Lagrange points (; also Lagrangian points or libration points) are points of equilibrium for small-mass objects under the influence of two massive orbiting bodies. Mathematically, this involves the solution of th ...

s of the gas giant.

References

External links

* {{Sky, 16, 24, 01.2899, -, 39, 11, 34.729, 41.96 G-type main-sequence stars Suspected variables Barium stars HD, 147513 Scorpii, 62 Durchmusterung objects Gliese and GJ objects 147513 080337 6094 Planetary systems with one confirmed planet

Properties

Planetary system

See also

References

External links