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Rossiter–McLaughlin Effect
The Rossiter–McLaughlin effect is a spectroscopic phenomenon observed when an object moves across the face of a star. Description The Rossiter–McLaughlin effect is a spectroscopic phenomenon observed when either an eclipsing binary's secondary star or an extrasolar planet is seen to transit across the face of the primary or parent star. As the main star rotates on its axis, one quadrant of its photosphere will be seen to be coming towards the viewer, and the other visible quadrant to be moving away. These motions produce blueshifts and redshifts, respectively, in the star's spectrum, usually observed as a broadening of the spectral lines. When the secondary star or planet transits the primary, it blocks part of the latter's disc, preventing some of the shifted light from reaching the observer. That causes the observed mean redshift of the primary star as a whole to vary from its normal value. As the transiting object moves across to the other side of the star's disc, the red ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animation Of The Rossiter-Mclaughlin (RM) Effect
Animation is a method by which image, still figures are manipulated to appear as Motion picture, moving images. In traditional animation, images are drawn or painted by hand on transparent cel, celluloid sheets to be photographed and exhibited on film. Today, most animations are made with computer-generated imagery (CGI). Computer animation can be very detailed Computer animation#Animation methods, 3D animation, while Traditional animation#Computers and traditional animation, 2D computer animation (which may have the look of traditional animation) can be used for stylistic reasons, low bandwidth, or faster real-time renderings. Other common animation methods apply a stop motion technique to two- and three-dimensional objects like cutout animation, paper cutouts, puppets, or Clay animation, clay figures. A cartoon is an animated film, usually a short film, featuring an cartoon, exaggerated visual style. The style takes inspiration from comic strips, often featuring anthropomorphi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hot Jupiter
Hot Jupiters (sometimes called hot Saturns) are a class of gas giant exoplanets that are inferred to be physically similar to Jupiter but that have very short orbital periods (). The close proximity to their stars and high surface-atmosphere temperatures resulted in their informal name "hot Jupiters". Hot Jupiters are the easiest extrasolar planets to detect via the radial-velocity method, because the oscillations they induce in their parent stars' motion are relatively large and rapid compared to those of other known types of planets. One of the best-known hot Jupiters is . Discovered in 1995, it was the first extrasolar planet found orbiting a Sun-like star. has an orbital period of about 4 days. General characteristics Though there is diversity among hot Jupiters, they do share some common properties. * Their defining characteristics are their large masses and short orbital periods, spanning 0.36–11.8 Jupiter masses and 1.3–111 Earth days. The mass c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planetary Science
Planetary science (or more rarely, planetology) is the scientific study of planets (including Earth), celestial bodies (such as moons, asteroids, comets) and planetary systems (in particular those of the Solar System) and the processes of their formation. It studies objects ranging in size from micrometeoroids to gas giants, aiming to determine their composition, dynamics, formation, interrelations and history. It is a strongly interdisciplinary field, which originally grew from astronomy and Earth science, and now incorporates many disciplines, including planetary geology, cosmochemistry, atmospheric science, physics, oceanography, hydrology, theoretical planetary science, glaciology, and exoplanetology. Allied disciplines include space physics, when concerned with the effects of the Sun on the bodies of the Solar System, and astrobiology. There are interrelated observational and theoretical branches of planetary science. Observational research can involve combinations of spac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dean Benjamin McLaughlin
Dean Benjamin McLaughlin (born October 25, 1901, Brooklyn, New York CIty; died December 8, 1965, Ann Arbor, Michigan, US) was an American astronomer. He was a professor of astronomy at the University of Michigan. He was the father of the science fiction author Dean B. McLaughlin, Jr. He received his B.S. (1923), his M.S. (1924) and his Ph.D. (1927) all from Michigan. McLaughlin married fellow astronomer Laura Elizabeth Hill in 1927. In 1954 he proposed the theory that there are volcanoes on Mars and that their eruptions change the albedo features called "mare" (The martian equivalent of Lunar mare). His proposal was partially confirmed in 1971 with the arrival of Mariner 9, which showed that strong winds could move dust around the planet, creating the changes of appearance formerly attributed to some kind of vegetatio A Impact crater, crater on Mars was named in his honor, as is the crater McLaughlin on the far side of the Moon and the asteroid 2024 McLaughlin. In 2014 NASA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Alfred Rossiter
Richard Alfred Rossiter (December 19, 1886 January 26, 1977) was an American astronomer, known for the Rossiter–McLaughlin effect. Rossiter served as director of the Lamont–Hussey Observatory from 1928 until 1952. Early life Rossiter was born in Oswego, New York, on December 19, 1886. He graduated from Wesleyan University in 1914, and married Jane van Dusen in 1915. He taught mathematics at Wesleyan Seminary for five years before enrolling in the astronomy program at the University of Michigan. He earned a master's degree in 1920, and a doctorate three years later. His doctoral dissertation, a study of the spectrum of Beta Lyrae, demonstrated that the shift that it exhibited could be accounted for by stellar rotation. Rossiter and his wife had two children, Laura and Alfred. Career Rossiter became the first director of the Lamont–Hussey Observatory in 1928. During this tenure at the observatory, he discovered more than 5,000 double stars. His ''Catalogue of Southern Doub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radial Velocity
The radial velocity or line-of-sight velocity, also known as radial speed or range rate, of a target with respect to an observer is the temporal rate of change, rate of change of the distance or Slant range, range between the two points. It is equivalent to the vector projection of the target-observer relative velocity onto the relative direction (geometry), relative direction connecting the two points. In astronomy, the point is usually taken to be the observer on Earth, so the radial velocity then denotes the speed with which the object moves away from the Earth (or approaches it, for a negative radial velocity). Formulation Given a differentiable vector \mathbf \in \mathbb^3 defining the instantaneous position of a target relative to an observer. Let with \mathbf \in \mathbb^3, the instantaneous velocity of the target with respect to the observer. The magnitude of the position vector \mathbf is defined as The quantity range rate is the time derivative of the magnitud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellar Rotation
Stellar rotation is the angular motion of a star about its axis. The rate of rotation can be measured from the spectrum of the star, or by timing the movements of active features on the surface. The rotation of a star produces an equatorial bulge due to centrifugal force. As stars are not solid bodies, they can also undergo differential rotation. Thus the equator of the star can rotate at a different angular velocity than the higher latitudes. These differences in the rate of rotation within a star may have a significant role in the generation of a stellar magnetic field. The magnetic field of a star interacts with the stellar wind. As the wind moves away from the star its rate of angular velocity slows. The magnetic field of the star interacts with the wind, which applies a drag to the stellar rotation. As a result, angular momentum is transferred from the star to the wind, and over time this gradually slows the star's rate of rotation. Measurement Unless a star is being observ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planetary Migration
Planetary migration occurs when a planet or other body in orbit around a star interacts with a disk of gas or planetesimals, resulting in the alteration of its orbital parameters, especially its semi-major axis. Planetary migration is the most likely explanation for hot Jupiters (exoplanets with Jovian masses but orbits of only a few days). The generally accepted theory of planet formation from a protoplanetary disk predicts that such planets cannot form so close to their stars, as there is insufficient mass at such small radii and the temperature is too high to allow the formation of rocky or icy planetesimals. It has also become clear that terrestrial-mass planets may be subject to rapid inward migration if they form while the gas disk is still present. This may affect the formation of the cores of the giant planets (which have masses of the order of 10 to 1000 Earth masses), if those planets form via the core-accretion mechanism. Types of disk Gas disk Observatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retrograde Motion
Retrograde motion in astronomy is, in general, orbital or rotational motion of an object in the direction opposite the rotation of its primary, that is, the central object (right figure). It may also describe other motions such as precession or nutation of an object's rotational axis. Prograde or direct motion is more normal motion in the same direction as the primary rotates. However, "retrograde" and "prograde" can also refer to an object other than the primary if so described. The direction of rotation is determined by an inertial frame of reference, such as distant fixed stars. In the Solar System, the orbits around the Sun of all planets and most other objects, except many comets, are prograde. They orbit around the Sun in the same direction as the sun rotates about its axis, which is counterclockwise when observed from above the Sun's north pole. Except for Venus and Uranus, planetary rotations around their axes are also prograde. Most natural satellites have prograde or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical Spectroscopy
Astronomical spectroscopy is the study of astronomy using the techniques of spectroscopy to measure the spectrum of electromagnetic radiation, including visible light, ultraviolet, X-ray, infrared and radio waves that radiate from stars and other celestial objects. A stellar spectrum can reveal many properties of stars, such as their chemical composition, temperature, density, mass, distance and luminosity. Spectroscopy can show the velocity of motion towards or away from the observer by measuring the Doppler shift. Spectroscopy is also used to study the physical properties of many other types of celestial objects such as planets, nebulae, galaxies, and active galactic nuclei. Background Astronomical spectroscopy is used to measure three major bands of radiation in the electromagnetic spectrum: visible light, radio waves, and X-rays. While all spectroscopy looks at specific bands of the spectrum, different methods are required to acquire the signal depending on the frequenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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