1.
John J. Kavelaars
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J-John Kavelaars, better known as JJ Kavelaars, is a Canadian astronomer who was part of a team that discovered several moons of Jupiter, Saturn, Uranus, and Neptune. Dr. Kavelaars, born in 1966, is a graduate of the Glencoe District High School in Glencoe, Ontario, the University of Guelph and he is currently an astronomer at the Dominion Astrophysical Observatory in Victoria, B. C. In the course of his work, he has been responsible for the discovery of eleven satellites of Saturn, eight of Uranus, and four of Neptune, Dr. Dr. Kavelaars is the brother of Canadian actress Ingrid Kavelaars and Canadian fencing athlete Monique Kavelaars. The asteroid 154660 Kavelaars was named in his honour on 1 June 2007 by his colleague David D. Balam, astronomy – John J. Kavelaars, Notable GDHS Graduates Homepage at NRC
2.
Brett J. Gladman
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He holds the Canada Research Chair in Planetary Astronomy. Gladman is best known for his work in astronomy in the Solar System. He also studies planet formation, especially the puzzle of how the giant planets came to be, Gladman was awarded the H. C. Urey Prize by the Division of Planetary Sciences of the American Astronomical Society in 2002, the main-belt asteroid 7638 Gladman is named in his honor. In 2008-2011 he served as member and chair of the Science Advisory Council of the Canada-France-Hawaii Telescope on Mauna Kea in Hawaii and he was awarded a Killam research fellowship in 2015. List of minor planet discoverers Brett Gladman at the Astronomy group of the Dept. of Physics and Astronomy, UBC and Institute of Planetary Science
3.
Matthew J. Holman
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Matthew J. Holman is a Smithsonian Astrophysicist and lecturer at Harvard University. Holman studied at MIT, where he received his bachelors degree in mathematics in 1989 and he was awarded the Newcomb Cleveland Prize in 1998. As of 25 January 2015, he holds the position of a director of IAUs Minor Planet Center, after former director Timothy B. He was a Salina Central High School classmate and fellow team member of Joe Miller. The main-belt asteroid 3666 Holman was named in his honour in 1999 and he was also part of a team that discovered numerous irregular moons, Discovered moons of Neptune, Halimede – in 2002 with J. J. Kavelaars, T. Grav, W. Fraser and D. Milisavljevic Sao – in 2002 with J. J, kavelaars, T. Grav, W. Fraser, D. Milisavljevic Laomedeia – in 2002, with J. J. Kavelaars, T. Grav, W. Fraser, D. Milisavljevic Neso – in 2002, Discovered moons of Uranus, Prospero – in 1999, with J. J. Petit, H. Scholl Setebos – in 1999, with J. J, petit, H. Scholl Stephano – in 1999, with B. Petit, H. Scholl Trinculo – in 2001, with J. J, kavelaars, D. Milisavljevic Francisco – in 2001, with J. J. Kavelaars, D. Milisavljevic, T. Grav Ferdinand – in 2001, with D. Milisavljevic, J. J
4.
Hans Scholl (astronomer)
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Hans Scholl is a German astronomer, who worked at the Astronomisches Rechen-Institut in Heidelberg, Germany, and at the Côte dAzur Observatory in Nice, France. In 1999, he was part of a team that discovered three moons of Uranus, Prospero, Setebos and Stephano and he has also co-discoverered 55 minor planets together with Italian astronomer Andrea Boattini at ESOs La Silla Observatory site in northern Chile during 2003–2005. Scholl is known for his work on the orbits of minor planets. He has studied the orbital resonance of outer main-belt asteroids, as well as the orbits of 2062 Aten, an object, and 2060 Chiron. His broad range of minor planet research included problems from mass determination to asteroid missions and he was honored by the outer main-belt asteroid 2959 Scholl, discovered by English–American astronomer Edward Bowell in 1983
5.
Orbital eccentricity
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The orbital eccentricity of an astronomical object is a parameter that determines the amount by which its orbit around another body deviates from a perfect circle. A value of 0 is an orbit, values between 0 and 1 form an elliptical orbit,1 is a parabolic escape orbit. The term derives its name from the parameters of conic sections and it is normally used for the isolated two-body problem, but extensions exist for objects following a rosette orbit through the galaxy. 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 limit case between an ellipse and a hyperbola, when e equals 1, is parabola, radial trajectories are classified as elliptic, parabolic, or hyperbolic based on the energy of the orbit, not the eccentricity. Radial orbits have zero angular momentum and hence eccentricity equal to one, keeping the energy constant and reducing the angular momentum, elliptic, parabolic, and hyperbolic orbits each tend to the corresponding type of radial trajectory while e tends to 1. For a repulsive force only the trajectory, including the radial version, is applicable. For elliptical orbits, a simple proof shows that arcsin yields the projection angle of a circle to an ellipse of eccentricity e. For example, to view the eccentricity of the planet Mercury, next, tilt any circular object by that angle and the apparent ellipse projected to your eye will be of that same eccentricity. From Medieval Latin eccentricus, derived from Greek ἔκκεντρος ekkentros out of the center, from ἐκ- ek-, eccentric first appeared in English in 1551, with the definition a circle in which the earth, sun. Five years later, in 1556, a form of the word was added. The eccentricity of an orbit can be calculated from the state vectors as the magnitude of the eccentricity vector, e = | e | where. For elliptical orbits it can also be calculated from the periapsis and apoapsis since rp = a and ra = a, where a is the semimajor axis. E = r a − r p r a + r p =1 −2 r a r p +1 where, rp is the radius at periapsis. For Earths annual orbit path, ra/rp ratio = longest_radius / shortest_radius ≈1.034 relative to center point of path, the eccentricity of the Earths orbit is currently about 0.0167, the Earths orbit is nearly circular. Venus and Neptune have even lower eccentricity, over hundreds of thousands of years, the eccentricity of the Earths orbit varies from nearly 0.0034 to almost 0.058 as a result of gravitational attractions among the planets. The table lists the values for all planets and dwarf planets, Mercury has the greatest orbital eccentricity of any planet in the Solar System. Such eccentricity is sufficient for Mercury to receive twice as much solar irradiation at perihelion compared to aphelion, before its demotion from planet status in 2006, Pluto was considered to be the planet with the most eccentric orbit
6.
Orbital inclination
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Orbital inclination measures the tilt of an objects orbit around a celestial body. It is expressed as the angle between a plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Earth directly above the equator, the plane of the orbit is the same as the Earths equatorial plane. The general case is that the orbit is tilted, it spends half an orbit over the northern hemisphere. If the orbit swung between 20° north latitude and 20° south latitude, then its orbital inclination would be 20°, the inclination is one of the six orbital elements describing the shape and orientation of a celestial orbit. It is the angle between the plane and the plane of reference, normally stated in degrees. For a satellite orbiting a planet, the plane of reference is usually the plane containing the planets equator, for planets in the Solar System, the plane of reference is usually the ecliptic, the plane in which the Earth orbits the Sun. This reference plane is most practical for Earth-based observers, therefore, Earths inclination is, by definition, zero. Inclination could instead be measured with respect to another plane, such as the Suns equator or the invariable plane, the inclination of orbits of natural or artificial satellites is measured relative to the equatorial plane of the body they orbit, if they orbit sufficiently closely. The equatorial plane is the perpendicular to the axis of rotation of the central body. An inclination of 30° could also be described using an angle of 150°, the convention is that the normal orbit is prograde, an orbit in the same direction as the planet rotates. Inclinations greater than 90° describe retrograde orbits, thus, An inclination of 0° means the orbiting body has a prograde orbit in the planets equatorial plane. An inclination greater than 0° and less than 90° also describe prograde orbits, an inclination of 63. 4° is often called a critical inclination, when describing artificial satellites orbiting the Earth, because they have zero apogee drift. An inclination of exactly 90° is an orbit, in which the spacecraft passes over the north and south poles of the planet. An inclination greater than 90° and less than 180° is a retrograde orbit, an inclination of exactly 180° is a retrograde equatorial orbit. For gas giants, the orbits of moons tend to be aligned with the giant planets equator, the inclination of exoplanets or members of multiple stars is the angle of the plane of the orbit relative to the plane perpendicular to the line-of-sight from Earth to the object. An inclination of 0° is an orbit, meaning the plane of its orbit is parallel to the sky. An inclination of 90° is an orbit, meaning the plane of its orbit is perpendicular to the sky