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HD 216770
HD 216770 is a star with an orbiting exoplanet in the southern constellation of Piscis Austrinus. With an apparent visual magnitude of 8.11, it is too faint to be visible to the naked eye. It is located at a distance of 120 light years from the Sun, as determined by parallax measurements, and is drifting further away with a radial velocity of 31.1 km/s. The star shows a high proper motion, traversing the celestial sphere at an angular rate of . The spectrum of HD 216770 presents as a late G-type main-sequence star, a yellow dwarf, with a stellar classification of G9VCN+1, where the suffix notation indicates anomalously strong band of CN. The star is smaller than the Sun, with 74% of the Sun's mass and 93% of the Sun's radius. It is about three billion years old and is spinning slowly with a rotation period of 35.6 days. The abundance of iron, a measure of the metallicity of the star, is higher than solar. The star is radiating 79% of the luminosity of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piscis Austrinus
Piscis Austrinus is a constellation in the southern celestial hemisphere. The name is Latin for "the southern fish", in contrast with the larger constellation Pisces, which represents a pair of fish. Before the 20th century, it was also known as Piscis Notius. Piscis Austrinus was one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations. The stars of the modern constellation Grus once formed the "tail" of Piscis Austrinus. In 1597 (or 1598), Petrus Plancius carved out a separate constellation and named it after the crane. It is a faint constellation, containing only one star brighter than 4th magnitude: Fomalhaut, which is 1st magnitude and the 18th-brightest star in the night sky. Fomalhaut is surrounded by a circumstellar disk, and possibly hosts a planet. Other objects contained within the boundaries of the constellation include Lacaille 9352, the brightest red dwarf star in the night sky (though still too f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotation Period
The rotation period of a celestial object (e.g., star, gas giant, planet, moon, asteroid) may refer to its sidereal rotation period, i.e. the time that the object takes to complete a single revolution around its axis of rotation relative to the background stars, measured in sidereal time. The other type of commonly used rotation period is the object's synodic rotation period (or ''solar day''), measured in solar time, which may differ by a fraction of a rotation or more than one rotation to accommodate the portion of the object's orbital period during one day. Measuring rotation For solid objects, such as rocky planets and asteroids, the rotation period is a single value. For gaseous or fluid bodies, such as stars and gas giants, the period of rotation varies from the object's equator to its pole due to a phenomenon called differential rotation. Typically, the stated rotation period for a gas giant (such as Jupiter, Saturn, Uranus, Neptune) is its internal rotation period, as d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 111232
HD 111232 is a star in the southern constellation of Musca. It is too faint to be visible with the naked eye, having an apparent visual magnitude of 7.59. The distance to this star is 94.5 light years based on parallax. It is drifting away from the Sun with a radial velocity of +104 km/s, having come to within some 264,700 years ago. The absolute magnitude of this star is 5.25, indicating it would have been visible to the naked eye at that time. This is an ancient, thick disk population II star with an estimated age of twelve billion years. It is a G-type main-sequence star with a stellar classification of G8 V Fe-1.0, indicating an anomalous underabundance of iron in the stellar atmosphere. The star has 80% of the mass of the Sun and 88% of the Sun's radius. It is spinning slowly with a projected rotational velocity of 0.4 km/s. X-ray emission has not been detected, suggesting a low level of coronal activity. The star is radiating 70% of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 108874
HD 108874 is a yellow dwarf star (spectral type G5 V) in the constellation of Coma Berenices. It is 195 light years from Earth and has two extrasolar planets that are possibly in a 9:2 orbital resonance. Star HD 108874 is probably billions of years older than the Sun however the age is not well constrained. The star has a temperature of about 5600 K. Its metallicity is 1.18 times that of the Sun, meaning it has greater iron abundance relative to hydrogen and helium. It has about the same mass as the Sun, but the radius is probably greater. Planetary system In 2003, the jovian planet HD 108874 b was discovered by the US-based team led by R. Paul Butler, Paul Butler, Geoffrey Marcy, Steven Vogt, and Debra Fischer. A total of 20 radial velocity observations, obtained at the W. M. Keck Observatory between 1999 and 2002, were used to make the discovery. In 2005, further observations revealed this star has another jovian planet orbiting further out, designated as HD 108874 c. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 10647
HD 10647 (q1 Eridani) is a 6th- magnitude yellow-white dwarf star, 57 light-years away in the constellation of Eridanus. The star is visible to the unaided eye under very dark skies. It is slightly hotter and more luminous than the Sun, and at 1.75 billion years old, it is also younger. An extrasolar planet was discovered orbiting this star in 2003. Planetary system In 2003, Michel Mayor's team announced the discovery of a new planet, HD 10647 b, in Paris at the XIX IAP Colloquium ''Extrasolar Planets: Today & Tomorrow'' The Anglo-Australian Planet Search team initially did not detect the planet in 2004, though a solution was made by 2006. The CORALIE data was finally published in 2013. The IRAS infrared space telescope detected an excess of infrared radiation from the star, indicating a possible circumstellar disk. Out of the 300 nearest Sun-like stars, the disk has the highest fractional luminosity out of all of them. It is unusually bright, but not unus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 216770 B
HD 216770 b is an extrasolar planet orbiting the star HD 216770. It has a mass about two thirds that of Jupiter, largest planet in the Solar System. But unlike the gas giants in the Solar System, it orbits in a very eccentric orbit around the star. The mean distance from the star is slightly larger than Mercury's, and it completes one orbit around the star in every 118 days. See also * HD 10647 b * HD 108874 b * HD 111232 b * HD 142415 b * HD 169830 c * HD 41004 Ab HD 41004 Ab is an extrasolar planet approximately 139 light years away in the constellation of Pictor. It has mass 2.56 MJ planet A planet is a large, rounded astronomical body that is neither a star nor its remnant. The best available t ... * HD 65216 b References External links * * Piscis Austrinus Exoplanets discovered in 2003 Giant planets Exoplanets detected by radial velocity {{extrasolar-planet-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Period
The orbital period (also revolution period) is the amount of time a given astronomical object takes to complete one orbit around another object. In astronomy, it usually applies to planets or asteroids orbiting the Sun, moons orbiting planets, exoplanets orbiting other stars, or binary stars. For celestial objects in general, the sidereal period ( sidereal year) is referred to by the orbital period, determined by a 360° revolution of one body around its primary, e.g. Earth around the Sun, relative to the fixed stars projected in the sky. Orbital periods can be defined in several ways. The tropical period is more particularly about the position of the parent star. It is the basis for the solar year, and respectively the calendar year. The synodic period incorporates not only the orbital relation to the parent star, but also to other celestial objects, making it not a mere different approach to the orbit of an object around its parent, but a period of orbital relations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Eccentricity
In astrodynamics, the orbital eccentricity of an astronomical object is a dimensionless parameter that determines the amount by which its orbit around another body deviates from a perfect circle. A value of 0 is a circular orbit, values between 0 and 1 form an elliptic orbit, 1 is a parabolic escape orbit (or capture orbit), and greater than 1 is a hyperbola. The term derives its name from the parameters of conic sections, as every Kepler orbit is a conic section. It is normally used for the isolated two-body problem, but extensions exist for objects following a rosette orbit through the Galaxy. Definition In a two-body problem with inverse-square-law force, every orbit is a Kepler orbit. The eccentricity of this Kepler orbit is a non-negative number that defines its shape. The eccentricity may take the following values: * circular orbit: ''e'' = 0 * elliptic orbit: 0 < ''e'' < 1 * [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 slightly less than one-thousandth the mass of the Sun. Jupiter is the List of brightest natural objects in the sky, third brightest natural object in the Earth's night sky after the Moon and Venus, and it has been observed since Pre-history, prehistoric times. It was named after the Jupiter (mythology), Roman god Jupiter, the king of the gods. Jupiter is primarily composed of hydrogen, but helium constitutes one-quarter of its mass and one-tenth of its volume. It probably has a rocky core of heavier elements, but, like the other giant planets in the Solar System, it lacks a well-defined solid surface. The ongoing contraction of Jupiter's interior generates more heat than it receives from the Sun. Because of its rapid rotation, the planet' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Plane
The orbital plane of a revolving body is the geometric plane in which its orbit lies. Three non-collinear points in space suffice to determine an orbital plane. A common example would be the positions of the centers of a massive body (host) and of an orbiting celestial body at two different times/points of its orbit. The orbital plane is defined in relation to a reference plane by two parameters: inclination (''i'') and longitude of the ascending node (Ω). By definition, the reference plane for the Solar System is usually considered to be Earth's orbital plane, which defines the ecliptic, the circular path on the celestial sphere that the Sun appears to follow over the course of a year. In other cases, for instance a moon or artificial satellite orbiting another planet, it is convenient to define the inclination of the Moon's orbit as the angle between its orbital plane and the planet's equatorial plane. Artificial satellites around the Earth For launch vehicles and ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inclination
Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a Plane of reference, reference plane and the orbital plane or Axis of rotation, axis of direction of the orbiting object. For a satellite orbiting the Earth directly above the Equator, the plane of the satellite's orbit is the same as the Earth's equatorial plane, and the satellite's orbital inclination is 0°. The general case for a circular orbit is that it is tilted, spending half an orbit over the northern hemisphere and half over the southern. If the orbit swung between 20° north latitude and 20° south latitude, then its orbital inclination would be 20°. Orbits The inclination is one of the six orbital elements describing the shape and orientation of a celestial orbit. It is the angle between the orbital plane and the plane of reference, normally stated in degree (angle), degrees. For a satellite orbiting a planet, the plane of reference is usually ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geneva Extrasolar Planet Search
The Geneva Extrasolar Planet Search is a variety of observational programs run by the Geneva Observatory at Versoix, a small town near Geneva, Switzerland. The programs are executed by M. Mayor, D. Naef, F. Pepe, D. Queloz, N.C. Santos, and S. Udry using several telescopes and instruments in the Northern and Southern Hemisphere and have resulted in the discovery of numerous extrasolar planets, including 51 Pegasi b, the first ever confirmed exoplanet orbiting a main-sequence star. Programs originated at Geneva are generally conducted in collaboration with several other academic institutions from Belgium, Germany, Italy and the United Kingdom. These programs search for exoplanets in various locations using different instruments. These include the Haute-Provence Observatory in France, the TRAPPIST and the Euler Telescope, both located at La Silla Observatory in Chile, as well as the M dwarf programs. Most recent projects involve the HARPS spectrograph, HARPS-N at the island of La ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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