An Etymological Dictionary of Astronomy and Astrophysics

The second brightest star in the constellation → Ursa Minor.
It is a reddish, evolved → giant of → spectral type K4 with a visual magnitude of 2.1. It is almost 500 times more luminous than the Sun and lies at a distance of 126 light years. Also called Kocab, Kochah.

See also: Kochab, from Ar. al-Kaukab (الکوکب) “star,” shortened from al-Kaukab al-shemali (الکوکب الشمالی) “North Star.”

The second brightest star in the constellation → Ursa Minor.
It is a reddish, evolved → giant of → spectral type K4 with a visual magnitude of 2.1. It is almost 500 times more luminous than the Sun and lies at a distance of 126 light years. Also called Kocab, Kochah.

See also: Kochab, from Ar. al-Kaukab (الکوکب) “star,” shortened from al-Kaukab al-shemali (الکوکب الشمالی) “North Star.”

The proportionality constant C in Kolmogorov’s mathematical analysis of → turbulence which states that the spectral energy E(k) in the range of turbulent scales is E(k) =C ε^2/3 k^-5/3, where k represents the → wave number (inversely proportional to the wavelength or → eddy size), and ε is the average energy dissipation per unit mass in the fluid. Experimental measurements give C close to 1.5.

See also: Andrei Nikolaevich Kolmogorov (1903-1987), a prominent Soviet mathematician, who made major advances in different scientific fields, mainly probability theory, topology, turbulence, classical mechanics, and computational complexity; → constant.

The proportionality constant C in Kolmogorov’s mathematical analysis of → turbulence which states that the spectral energy E(k) in the range of turbulent scales is E(k) =C ε^2/3 k^-5/3, where k represents the → wave number (inversely proportional to the wavelength or → eddy size), and ε is the average energy dissipation per unit mass in the fluid. Experimental measurements give C close to 1.5.

See also: Andrei Nikolaevich Kolmogorov (1903-1987), a prominent Soviet mathematician, who made major advances in different scientific fields, mainly probability theory, topology, turbulence, classical mechanics, and computational complexity; → constant.

Length scale of → turbulent flow below which the effects of molecular → viscosity are non-negligible.

See also: → Kolmogorov constant; → scale.

Length scale of → turbulent flow below which the effects of molecular → viscosity are non-negligible.

See also: → Kolmogorov constant; → scale.

The distribution of energy over different scales in a → turbulent flow where → energy cascade occurs. Let E be the energy per unit → wave number (k)
and ε the energy → dissipation parameter, E = E(k,ε). → Dimensional analysis yields: E = Cε^2/3k^-5/3, where C is the → Kolmogorov constant.

See also: A. N. Kolmogorov, 1941, Local structure of turbulence in an incompressible fluid for very large Reynolds numbers, Doklady Acad Sci. USSR 31, 301;
→ spectrum.

The distribution of energy over different scales in a → turbulent flow where → energy cascade occurs. Let E be the energy per unit → wave number (k)
and ε the energy → dissipation parameter, E = E(k,ε). → Dimensional analysis yields: E = Cε^2/3k^-5/3, where C is the → Kolmogorov constant.

See also: A. N. Kolmogorov, 1941, Local structure of turbulence in an incompressible fluid for very large Reynolds numbers, Doklady Acad Sci. USSR 31, 301;
→ spectrum.

An ice-filled → impact crater located in the northern lowlands of Mars at 73° north latitude and 165° east longitude, south of the large Olympia Undae dune field that partly surrounds Mars’ north polar cap.

Korolev crater is 82 km across with its centre hosting a mound of water ice some 1.8 kilometres thick all year round. The reason for the permanently stable water ice in the crater is because its deepest part acts as a natural cold trap. The air above the ice cools and is thus heavier compared to the surrounding air: since air is a poor conductor of heat, the water ice mound is effectively shielded from heating and sublimation.

See also: The crater is named after chief rocket engineer and spacecraft designer Sergei Korolev (1907-1966), dubbed the father of Soviet space technology.

An ice-filled → impact crater located in the northern lowlands of Mars at 73° north latitude and 165° east longitude, south of the large Olympia Undae dune field that partly surrounds Mars’ north polar cap.

Korolev crater is 82 km across with its centre hosting a mound of water ice some 1.8 kilometres thick all year round. The reason for the permanently stable water ice in the crater is because its deepest part acts as a natural cold trap. The air above the ice cools and is thus heavier compared to the surrounding air: since air is a poor conductor of heat, the water ice mound is effectively shielded from heating and sublimation.

See also: The crater is named after chief rocket engineer and spacecraft designer Sergei Korolev (1907-1966), dubbed the father of Soviet space technology.

In the → three-body problem, the → perturbation of the orbit of a → secondary body by the garvity of a third body located at a distance much larger than the separation between the → primary body and the secondary. The secondary’s orbit oscillates about a constant value involving a periodic exchange between the extreme values of its → inclination and orbital → eccentricity. The Kozai-Lidov mechanism results from the conservation of the quantity (1 - e²)^1/2.cos i for each component, where e is eccentricity and i is inclination. The total → angular momentum of the system remains constant while the angular momentum is exchanged betwwen the components. It has been suggested that the Kozai mechanism is responsible for the high eccentricities observed in the orbits of → extrasolar planets. If the parent star has a massive yet unseen substellar companion, orbiting at a great distance, and in an orbit highly inclined to the plane of the planets’ orbits, the mechanism should induce high eccentricities into the orbits of the planets. Similarly, this mechanism may be responsible for the high eccentricities observed in the orbits of many → Kuiper Belt Objects such as 2003 UB313.

See also: Named for the japanese Yoshihide Kozai (1962, Astronomical J. 67, 591), and the Russian Michael Lidov (1962, Planetary & Space Science 9, 719).

In the → three-body problem, the → perturbation of the orbit of a → secondary body by the garvity of a third body located at a distance much larger than the separation between the → primary body and the secondary. The secondary’s orbit oscillates about a constant value involving a periodic exchange between the extreme values of its → inclination and orbital → eccentricity. The Kozai-Lidov mechanism results from the conservation of the quantity (1 - e²)^1/2.cos i for each component, where e is eccentricity and i is inclination. The total → angular momentum of the system remains constant while the angular momentum is exchanged betwwen the components. It has been suggested that the Kozai mechanism is responsible for the high eccentricities observed in the orbits of → extrasolar planets. If the parent star has a massive yet unseen substellar companion, orbiting at a great distance, and in an orbit highly inclined to the plane of the planets’ orbits, the mechanism should induce high eccentricities into the orbits of the planets. Similarly, this mechanism may be responsible for the high eccentricities observed in the orbits of many → Kuiper Belt Objects such as 2003 UB313.

See also: Named for the japanese Yoshihide Kozai (1962, Astronomical J. 67, 591), and the Russian Michael Lidov (1962, Planetary & Space Science 9, 719).