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In astronomy, seeing is the degradation of the image of an astronomical object due to turbulence in the atmosphere of Earth that may become visible as blurring, twinkling or variable distortion. The origin of this effect is rapidly changing variations of the optical refractive index along the light path from the object to the detector.
Orbital Parameters of a Cosmic Object: . α - RA, right ascension, if the Greek letter does not appear, á letter will appear. δ - Dec, declination, if the Greek letter does not appear, ä letter will appear.
This glossary of astronomy is a list of definitions of terms and concepts relevant to astronomy and cosmology, their sub-disciplines, and related fields. Astronomy is concerned with the study of celestial objects and phenomena that originate outside the atmosphere of Earth. The field of astronomy features an extensive vocabulary and a ...
Radar is used to measure the distance between the orbits of the Earth and of a second body. From that measurement and the ratio of the two orbit sizes, the size of Earth's orbit is calculated. The Earth's orbit is known with an absolute precision of a few meters and a relative precision of a few parts in 100 billion (1 × 10 −11).
Atmospheric windows are useful for astronomy, remote sensing, telecommunications and other science and technology applications. In the study of the greenhouse effect , the term atmospheric window may be limited to mean the infrared window , which is the primary escape route for a fraction of the thermal radiation emitted near the surface.
Habitable zone (HZ) (also called the circumstellar habitable zone), the orbit around a star that would allow liquid water to remain for a short period of time (a given period of time) on at least a small part of the planet's surface. Thus within the HZ, water, (H 2 O) is between 0 °C (32 °F; 273 K) and 100 °C (212 °F; 373 K) temperature.
In astronomy and celestial navigation, an ephemeris (/ ɪ ˈ f ɛ m ər ɪ s /; pl. ephemerides / ˌ ɛ f ə ˈ m ɛr ɪ ˌ d iː z /; from Latin ephemeris 'diary', from Ancient Greek ἐφημερίς (ephēmerís) 'diary, journal') [1] [2] [3] is a book with tables that gives the trajectory of naturally occurring astronomical objects and artificial satellites in the sky, i.e., the position ...
For Earth's tides one can calculate the tilt factor as + and the gravimetric factor as + (/), where subscript two is assumed. [ 5 ] Neutron stars are thought to have high rigidity in the crust, and thus a low Love number: 0.05 ≤ k 2 ≤ 0.17 {\displaystyle 0.05\leq k_{2}\leq 0.17} ; [ 6 ] [ 7 ] isolated, nonrotating black holes in vacuum have ...