Parameters characterizing properties of our galaxy
The Oort constants (discovered by Jan Oort) and are empirically derived parameters that characterize the local rotational properties of our galaxy, the Milky Way, in the following manner:
where and are the rotational velocity and distance to the Galactic Center, respectively, measured at the position of the Sun, and v and r are the velocities and distances at other positions in our part of the galaxy. As derived below, A and B depend only on the motions and positions of stars in the solar neighborhood. As of 2018, the most accurate values of these constants are = 15.3 ± 0.4 km s−1 kpc−1, = −11.9 ± 0.4 km s−1 kpc−1.[1] From the Oort constants, it is possible to determine the orbital properties of the Sun, such as the orbital velocity and period, and infer local properties of the Galactic disk, such as the mass density and how the rotational velocity changes as a function of radius from the Galactic Center.
^Bovy, J. (June 2017). "Galactic rotation in Gaia DR1". MNRAS. 468 (1): L63–L67. arXiv:1610.07610. Bibcode:2017MNRAS.468L..63B. doi:10.1093/mnrasl/slx027.
The Oortconstants (discovered by Jan Oort) A {\displaystyle A} and B {\displaystyle B} are empirically derived parameters that characterize the local...
occupied by the planets." The Oort cloud, the Oortconstants, and the asteroid 1691 Oort were all named after him. Oort was born in Franeker, a small...
The Oort cloud (/ɔːrt, ʊərt/), sometimes called the Öpik–Oort cloud, is theorized to be a vast cloud of icy planetesimals surrounding the Sun at distances...
rotation at the sun, Ω, approximately 5.7 milliarcseconds per year (see Oortconstants). An object's location expressed in the equatorial coordinate system...
portal Baade's Window Galactic astronomy Galactic Center GeV excess Oortconstants The distance towards its center (Sagittarius A*). This is the diameter...
cloud (also called the inner Oort cloud and inner cloud) is a theoretical vast circumstellar disc, interior to the Oort cloud, whose outer border would...
orbiting the Milky Way but outside the main disk. The Oort constants (discovered by Jan Oort) A {\displaystyle A} and B {\displaystyle B} are empirically...
existence of which was first posited in the 1930s by Jan Oort in his measurements of the Oortconstants and Fritz Zwicky in his studies of the masses of galaxy...
galactic rotation in the solar neighborhood is encapsulated in the Oortconstants. Structural components of the Milky Way: Using stellar kinematics, astronomers...
interstellar space. The outermost region of the Solar System is the theorized Oort cloud, the source for long-period comets, extending to a radius of 2,000–200...
the Galaxy. These discoveries were published in 1940 and were noted by Jan Oort who knew that significant advances could be made in astronomy if there were...
as 100 AU from the Sun. The Kuiper belt is distinct from the hypothesized Oort cloud, which is believed to be a thousand times more distant and mostly spherical...
1951. Using the radio telescope at the Kootwijk Observatory, Muller and Oort reported the detection of the hydrogen emission line in May of that same...
Schweiz. Retrieved 20 May 2016. Kruit, Pieter C. van der (2019). Jan Hendrik Oort: Master of the Galactic System. Springer. p. 639. ISBN 978-3-030-17801-7...
(Johannes) Oort, Jacob Albert van den Berg In Search of Truth. Augustine, Manichaeism and Other Gnosticism: Studies for Johannes Van Oort at Sixty BRILL...
trans-Neptunian objects (objects in the Kuiper belt, scattered disc or inner Oort cloud). For a complete list of minor planets in numerical order, see List...
the constant of aberration and the Gaussian gravitational constant) were incorporated into the first international system of astronomical constants in...
Solar System continues into the Kuiper belt, the scattered disc, and the Oort cloud, three sparse populations of small icy bodies thought to be the points...
orbit in its current location, but would not do so if it orbited in the Oort cloud. The smaller planets retain only silicates and metals, and are terrestrial...
the Kuiper belt objects, the scattered disc objects, the sednoids, and the Oort cloud objects. About 60% of the main belt mass is contained in the four largest...
to reach the Sun’s inner gravitational focus, with arrival at the inner Oort Cloud in no more than thirty years." "Such a mission could perform useful...
Gnus 5.10 (Oort Gnus) – May 1, 2003 Gnus 5.11, a rebranded 5.10 bundled with GNU Emacs 22.1 (June 2, 2007). 5.10/5.11 development from the "Oort" development...
and Enceladus Pluto–Charon system Comets and other related Kuiper belt and Oort cloud objects And is also likely present on: Mercury's poles Tethys Water...
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