angular diameter
The angle that the actual diameter of an object makes in the sky; also known as angular size or apparent diameter.
Angular Diameter
When we look at objects in the night sky, we often do not know how far away they are.
diameter (in asteroid (astronomy): Size and albedo)
About 30 asteroids are larger than 200 km. The largest, Ceres, has a diameter of about 940 km. It is followed by Vesta at 530 km, Pallas at 510 km, and (10) Hygiea at 410 km.
Diameters of the Largest Satellites and the Planets
miles
miles ...
Diameter Distance
Any distance to a celestial object which is based upon the use of a standard ruler.
Down ...
semidiameter (of the sun): [s, S] half the angular size of the sun (or, more correctly, its photosphere). As the distance from the Earth to the sun varies during its orbit, the semi-diameter varies from 15.76 arc-minutes in July to 16.
Mira's Diameter
The measured diameter of the star is about 7 AU, that is, about 670 million miles, or something greater than the diameter of the asteroid belt in between the orbits of Mars and Jupiter in the solar system.
Angular diameter The apparent diameter of an object measured in degrees or radians.
Angular separation The angular distance between two celestial bodies measured in degrees.
angular diameter: A measure of the size of an object in the sky; numerically equal to the angle in degrees between two lines extending from the observer's eye to opposite edges of the object.
Angular diameter. The apparent size of an object, usually expressed in degrees, minutes, or seconds of arc.
The angular diameter - redshift test looks for a breakdown of the inversion relation between distance and angular diameter of some set of standard measuring rods (say galaxy isophotes or radio-galaxy lobe separations).
Diameter
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle....
diameter of the Earth 13,000 km
height of a geostationary satellite 36,000 km
distance of the Moon 384,000 km
distance of the Sun 150,000,000 km - 1 Astronomical Unit (AU) ...
DIAMETER
The diameter is the longest distance from one side of a circle (or a sphere) to the other.
Diameter
The distance from one side of a circle to the other measured through the center. For telescopes, the diameter of a lens or mirror is measured from one side to the opposite side, passing through the center.
Differentiation ...
so diameter = 2r = 2(3.86 × 1026/(4π × 5.67 × 10-8 × (5.78 × 103)4))1/2
and ∴ Sun's diameter = 1,390,000 km (or 1.39 × 109 m).
If a star is 20 parsecs away and has an apparent magnitude of +6, what is its absolute magnitude?
The diameter of the objective is referred to as the aperture; it typically ranges from a few centimeters for small spotting telescopes up to one meter for the largest refractor in existence.
The diameter of our closest star, the Sun, is 1,392,000 kilometers. The Sun is thought to be 4.6 billion years old. The Sun is a medium size star known as a yellow dwarf.
The diameter of the eventual crater is typically 10 times that of the incoming meteoroid; the crater depth is about twice the meteoroid's diameter.
The diameter of Mars is about 53% that of Earth, and its mass is only 10% that of the Earth's. Mars has a polar diameter of 4,195.7 miles (6,752.4 km) and an equatorial diameter of 4,220.6 miles (6,792.4 km). Mars's surface gravity is 38% of Earth's.
The diameter of the deformable mirror is usually in the range of 8 to 20 centimeters, but work is being done on larger secondary mirrors.
Its diameter is about 23 arc minutes and is readily viewable in small telescopes. Nearby is NGC 6207, a 12th magnitude edge on galaxy that lies 28 arc minutes directly north east. The J2000 coordinates are RA: 16h 41m 41.5s and Dec: +36° 27' 37".
The diameter 2R of the Earth is much bigger than h, and therefore the error introduced if (2R+h) is replaced by 2R is very, very small. Carrying out this replacement gives
2Rh = D2
D = √(2Rh) ...
The diameter was considerably smaller than Mercury's and its mass was estimated at one-seventeenth of Mercury's mass. This was too small to account for the deviations of Mercury's orbit.
the diameter of a telescope's primary lens or mirror; the larger the aperture, the greater the telescope's light-gathering power
aphelion
the point farthest from the sun in an object's orbit ...
The diameters of the two bodies could be measured accurately for the first time during the eclipses. Pluto turns out to be only about 2300 kilometers across (1400 miles) - clearly making it the smallest planet in the solar system.
The diameter of Sirius A was first measured by Robert Hanbury Brown and Richard Q. Twiss in 1959 at Jodrell Bank using their stellar intensity interferometer.
Mean Diameter
26 x 20 x 16 km (16.2 x 12.4 x 9.9 miles)
Year Discovered ...
Mean diameter
(km) Satellites of planets Dwarf planet satellites Satellites of
SSSBs Non-satellites
for comparison Earth Mars Jupiter Saturn Uranus Neptune Pluto Haumea Eris 6000-8000 ...
2 The diameter of Venus was measured with one of these heliometers at the observatory of Breslau by Brandes in 1820 (Berlin Jahrbuch, 1824, p. 064).
are made with the moving segment displaced alternately on opposite sides of the fixed segment.
With a diameter of 5,262 kilometres, Ganymede is the largest moon in the Solar System, and is even larger than both planet Mercury and dwarf planet Pluto. It is also the only satellite in the Solar System known to have its own magnetosphere.
With a diameter between 750 and 753 miles (1,207 and 1,212 kilometers), Charon is the largest moon with respect to its primary planet in the Solar System. Its density is 1.
With a diameter of about 1,400 kilometers (890 miles), Iapetus is Saturn's third largest moon. It was discovered by Jean-Dominique Cassini in 1672.
A star's diameter is found from speed = (distance travelled)/(time it takes). The speed comes from the doppler shift and the time is the length of the eclipse.
When its diameter was established (through observation in 2005) a conundrum arose for astronomers all over the world. Was it the tenth planet?
The 26 m diameter subnet is used for rapidly tracking Earth-orbiting spacecraft. They were originally built to support the Apollo lunar missions between 1967 and 1972.
A small (diameter up to several hundred kilometers) solar-system body of the type that first condensed from the solar nebula. Planetesimals are thought to have been the principal bodies that combined to form the planets.
plasma - (n.) ...
Jupiter's diameter is 88,700 miles (142,800 km). This is a little more than 11 times the diameter of the Earth. Jupiter is so big that all the other planets in our Solar System could fit inside Jupiter (if it were hollow).
Equatorial Diameter
The distance accross the centre of a planet or moon.
ESA ...
Fill in the diameter of the Sun you want your model to be scaled by. You can fill in either the red bordered inches box or the green bordered millimeters box. Important: Only fill in one box.
What is the diameter of Sinope?
What is Jupiter IX?
How far from Jupiter is Sinope?
Who discovered Sinope?
What is the orbit of Sinope?
What is Sinope?
Wmat makes up the atmosphere on Mars?
Who was Cleomedes?
What made Cleomedes famous?
Uranus has a diameter of 52,200 km (32,500 mi), and its mean distance from the sun is 2.87 billion km (1.78 billion mi). Uranus takes 84.
Triton has a diameter of about 2,705 kilometers (1,680 miles) and a mean density of about 2.066 grams per cubic centimeter (the density of water is 1.0 gram per cubic centimeter).
aperture: the diameter of a telescope's main lens or mirror, and the scope's most important attribute.
asterism: any prominent star pattern that isn't a whole constellation (such as the Big Dipper).
8-mile-diameter estimate comes from assuming the neutron star is at the farthest it can be, just in front of the obscuring "wall" of the molecular cloud.
Half the long diameter of an ellipse
Seyfert Galaxy
An otherwise normal spiral galaxy with an unusually bright, small core that fluctuates in brightness; believed to indicate the core is erupting.
diameters (NASA Thesaurus) Lengths of the longest straight lines through the centers of the largest cross sections.
The equatorial diameter of Saturn, 120,536 kilometres, is measured with respect to the one-bar pressure level in its atmosphere, for Saturn has no solid surface in its outer layers.
Primary mirror diameter: 6.5 m
Mass: 11,000 lbs
Cost: $824.8 million
Orbit: 1.5 million km, at the L2 Point
Operating temperature: <50K ...
The star has a diameter of about 65,000 km (40,000 miles), or about five times that of the Earth.
[A] 3 meters in diameter and infinite in thickness
[B] 200 meters in diameter and a meter in thickness
[C] 50 meters in diameter and 10 meters in thickness
The biggest problem for Air Cerenkov detectors is: ...
The partial convective mixing that takes place in a convectively unstable region where stability can be attained by the results of the mixing before the region is completely mixed. [H76]
Semi-Diameter ...
FIGURE: The diameter of the Sun and its distance away from us are related by the apparent angular size of the Sun. The ratio of the diameter to the distance is equal to the size of the angle in radians.
primary mirror: diameter = 20" (508 mm), FL = 2033.7 mm (f4), enhanced aluminum coating
secondary mirror: minor axis = 4" (101.6 mm), enhanced aluminum coating
finders: ...
This 54-km (32-mi) diameter is the size at which craters on begin to possess peak-rings instead of a single central peak. The floor of crater is flat and radar-dark, indicating possible infilling by lava flows sometime following the impact.
70 times the sun's diameter
How Bright:
40,000 times the sun's luminosity (Absolute visual magnitude = - 6.8) ...
1. An object with a diameter of 38 cm is located 688 m away. What is its angular size?
The geocentric parallax when a body is in the horizon is called horizontal parallax and is the angular semidiameter of the earth as seen from the body. Parallax of the moon is called lunar parallex.
The first monument consisted of a circular bank and ditch enclosure made of Late Cretaceous (Santonian Age) Seaford Chalk, (7 and 8) measuring around 110 m (360 feet) in diameter with a large entrance to the north east and a smaller one to the south ...
Does the diameter of the star matter when determining the Temperature? What is the ratio of the peak wavelength emitted by star one to the peak wavelength emitted by star two if the surface temperature of star one is twice that of star two?
 See also: Earth, Sun, Light, Orbit, Solar
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