HD 59686
Encyclopedia
HD 59686 is a 5th magnitude
star
approximately 316 light years away in the constellation
Gemini
.
in its core and on its way to becoming a red giant
. The stellar radius is very large (11.6 times that of our Sun).
was announced orbiting the giant star
by Mitchell which he used Doppler spectrometer to look for effects on the star caused by the gravitational tug of the orbiting planet. Using the amplitude from the radial velocity method, he calculated the planetary mass
as 5.25 Jupiter mass
es and with period
303 days. However the mass is only minimum because the inclination
of the orbit is not known. Using the stellar mass and period, he calculated semimajor axis as 0.911 astronomical unit
s. He found that the shape of the stellar wobble
is circular, implying that the planet has zero eccentricity
.
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...
star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
approximately 316 light years away in the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
Gemini
Gemini (constellation)
Gemini is one of the constellations of the zodiac. It was one of the 48 constellations described by the 2nd century astronomer Ptolemy and it remains one of the 88 modern constellations today. Its name is Latin for "twins", and it is associated with the twins Castor and Pollux in Greek mythology...
.
Star
It is an orange giant meaning it has ceased fusing hydrogenHydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
in its core and on its way to becoming a red giant
Red giant
A red giant is a luminous giant star of low or intermediate mass in a late phase of stellar evolution. The outer atmosphere is inflated and tenuous, making the radius immense and the surface temperature low, somewhere from 5,000 K and lower...
. The stellar radius is very large (11.6 times that of our Sun).
Planetary system
In November 2003, the planetExtrasolar planet
An extrasolar planet, or exoplanet, is a planet outside the Solar System. A total of such planets have been identified as of . It is now known that a substantial fraction of stars have planets, including perhaps half of all Sun-like stars...
was announced orbiting the giant star
Giant star
A giant star is a star with substantially larger radius and luminosity than a main sequence star of the same surface temperature. Typically, giant stars have radii between 10 and 100 solar radii and luminosities between 10 and 1,000 times that of the Sun. Stars still more luminous than giants are...
by Mitchell which he used Doppler spectrometer to look for effects on the star caused by the gravitational tug of the orbiting planet. Using the amplitude from the radial velocity method, he calculated the planetary mass
Mass
Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
as 5.25 Jupiter mass
Jupiter mass
Jupiter mass , is the unit of mass equal to the total mass of the planet Jupiter . Jupiter mass is used to describe masses of the gas giants, such as the outer planets and extrasolar planets. It is also used in describing brown dwarfs....
es and with period
Orbital period
The orbital period is the time taken for a given object to make one complete orbit about another object.When mentioned without further qualification in astronomy this refers to the sidereal period of an astronomical object, which is calculated with respect to the stars.There are several kinds of...
303 days. However the mass is only minimum because the inclination
Inclination
Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...
of the orbit is not known. Using the stellar mass and period, he calculated semimajor axis as 0.911 astronomical unit
Astronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
s. He found that the shape of the stellar wobble
Stellar wobble
Stellar wobble is a variation in the position of a star due to the gravitational influence of another body orbiting it. Stellar wobble is visible as a Doppler shift in the star's spectrum or as a motion of the star in the plane of the sky...
is circular, implying that the planet has zero eccentricity
Orbital eccentricity
The orbital eccentricity of an astronomical body is the amount by which its orbit deviates from a perfect circle, where 0 is perfectly circular, and 1.0 is a parabola, and no longer a closed orbit...
.