GD 66 b
Encyclopedia
GD 66 b is an unconfirmed extrasolar planet
orbiting the DAV type pulsating white dwarf
GD 66
. Small variations in the phase of pulsation suggest that the star is moving in a small circle due to the gravitational pull of a smaller unseen body. This method is similar to that used to discover pulsar planet
s, except that the observations were in visible light instead of radio waves. The planet has not yet completed a full orbit during the time of observations and only one turning point
of the observed-computed time curve has been observed, which makes it difficult to constrain the orbital parameters. The current best-fit circular orbit has a period of 5.69 years, with a planetary mass at least 2.36 times that of Jupiter
(the measured quantity is the product
of the true mass with the sine
of the orbit's inclination
angle). Observations made with the Spitzer Space Telescope
failed to detect the planet, allowing an upper limit to be placed on its mass of 5–6 Jupiter mass
es.
Extrasolar 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...
orbiting the DAV type pulsating white dwarf
Pulsating white dwarf
A pulsating white dwarf is a white dwarf star whose luminosity varies due to non-radial gravity wave pulsations within itself. Known types of pulsating white dwarfs include DAV, or ZZ Ceti, stars, with hydrogen-dominated atmospheres and the spectral type DA, pp. 891, 895; DBV, or V777 Her,...
GD 66
GD 66
GD 66 or V361 Aurigae is a 0.64 solar mass pulsating white dwarf star located 170 light years from Earth in the Auriga constellation. The estimated cooling age of the white dwarf is 500 million years...
. Small variations in the phase of pulsation suggest that the star is moving in a small circle due to the gravitational pull of a smaller unseen body. This method is similar to that used to discover pulsar planet
Pulsar planet
Pulsar planets are planets that are found orbiting pulsars, or rapidly rotating neutron stars. The first such planet to be discovered was around a millisecond pulsar and was the first extrasolar planet to be confirmed as discovered.-Pulsar planets:...
s, except that the observations were in visible light instead of radio waves. The planet has not yet completed a full orbit during the time of observations and only one turning point
Turning Point
Turning point may refer to:* A a point at which the derivative changes sign. See stationary point, in mathematics* A climax , in narrative structure* A discrimen, one of the two marked points on a cursus or classical-period race-track...
of the observed-computed time curve has been observed, which makes it difficult to constrain the orbital parameters. The current best-fit circular orbit has a period of 5.69 years, with a planetary mass at least 2.36 times that of Jupiter
Jupiter
Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...
(the measured quantity is the product
Product (mathematics)
In mathematics, a product is the result of multiplying, or an expression that identifies factors to be multiplied. The order in which real or complex numbers are multiplied has no bearing on the product; this is known as the commutative law of multiplication...
of the true mass with the sine
Sine
In mathematics, the sine function is a function of an angle. In a right triangle, sine gives the ratio of the length of the side opposite to an angle to the length of the hypotenuse.Sine is usually listed first amongst the trigonometric functions....
of the orbit's 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...
angle). Observations made with the Spitzer Space Telescope
Spitzer Space Telescope
The Spitzer Space Telescope , formerly the Space Infrared Telescope Facility is an infrared space observatory launched in 2003...
failed to detect the planet, allowing an upper limit to be placed on its mass of 5–6 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.