ellipticity
51PSR B1829-10 — Starbox begin name = PSR B1829 10Starbox observe epoch = J2000.0 constell = Scutum ra = RA|18|32|40.866 dec = DEC| 10|21|32.78 appmag v = 5.28Starbox character class = Pulsar r i = v r = b v = u b = variable = None Starbox astrometry radial v =… …
52National Geographic Society - Palomar Observatory Sky Survey — The National Geographic Society Palomar Observatory Sky Survey (NGS POSS) [A. G. Wilson, Trans. I.A.U. 8, 335–336 (1952); [http://adsabs.harvard.edu/abs/1963bad..book..481M R. L. Minkowski G. O. Abell, in Basic Astronomical Data: Stars and… …
53Orbital station-keeping — In astrodynamics orbital station keeping is a term used to describe the orbital maneuvers made by thruster burns that are needed to keep a spacecraft in a particular assigned orbit. For many Earth satellites the effects of the non Keplerian… …
54Polar night — Typical blue twilight experienced during the polar night in Longyearbyen, Svalbard located at 78 degrees north. The polar night occurs when the night lasts for more than 24 hours. This occurs only inside the polar circles. The opposite… …
55Moon illusion — The Moon illusion is an optical illusion in which the Moon appears larger near the horizon than it does while higher up in the sky. This optical illusion also occurs with the sun and star constellations. It has been known since ancient times, and …
56Clairaut's theorem — For the interpretation of this theorem in terms of symmetry of second derivatives of a mapping , see Symmetry of second derivatives. Figure 1: An ellipsoid …
57Solid state nuclear track detector — A solid state nuclear track detector or SSNTD (also known as an etched track detector or a dielectric track detector, DTD) is a sample of a solid material (photographic emulsion, crystal, glass or plastic) exposed to nuclear radiation (neutrons… …
58Gabor filter — A Gabor filter is a linear filter whose impulse response is defined by a harmonic function multiplied by a Gaussian function. Because of the multiplication convolution property (Convolution theorem), the Fourier transform of a Gabor filter s… …
59Free-fall time — The free fall time is the characteristic time that would take a body to collapse under its own gravitational attraction, if no other forces existed to oppose the collapse. As such, it plays a fundamental role in setting the timescale for a wide… …
60Draco Dwarf — Central part of Draco Dwarf by HST Observation data (J2000 epoch) Constellation …
