Sextant
Related Category: Astronomy: General
instrument for measuring the altitude of the sun or another celestial body; such measurements can then be used to determine the observer's geographical position or for other navigational, surveying, ...
Sextant
A sextant is a measuring instrument generally used to measure the angle of elevation of a celestial object above the horizon. Making this measurement is known as sighting the object, shooting the object or taking a sight.
sextant
Home ... Science and Technology Astronomy and Space Exploration Astronomy: General ...
Essential reading Compare
side-by-side The Oxford Essential Dictionary of the U.S. Military The Columbia Encyclopedia, Sixth Edition ...
Sextant :
An instrument for determining the angle between the horizon and a celestial body such as the Sun, the Moon, or a star, used in celestial navigation to determine latitude and longitude.
sextant: a navigational instrument for measuring celestial angles, particularly the height (altitude) of the sun or fixed stars.
SEXTANT
The sextant is an astronomical instrument that is used to determine latitude for navigation. It does this by measuring angular distances, like the altitude of the sun, moon and stars.
Sextant
Instrument employed to measure the elevation of astronomical objects above the horizon. Based upon an arc equal to a sixth of a circle, sextants are more compact and easier to use than are the quadrants that preceded them.
Sextant
The first sextant was constructed in Ray, Iran, by Abu-Mahmud al-Khujandi in 994.
Sextants for astronomical observations were used primarily for measuring the positions of stars. They are little used today, having been replaced over time by transit telescopes, astrometry techniques, and satellites such as Hipparcos....
Sextans (Sextant)
Bronze Saint Yulij (Gigantomachia)
Origin of the constellation: 17th century, Hevelius ...
Sextans, the sextant:
A modern constellation created by Polish astronomer Johannes Hevelius in 1690. Originally it was called Sextans Uraniae.
Sextans, "The Sextant" is one of a number of constellations devised by Johannes Hevelius, and published posthumously in 1690. For further remarks on Hevelius, see "Lacerta".
Make-Your-Own Sextant (Quadrant) Kit
$16.00
North Circumpolar Constellations Coloring Book ...
Using a marine sextant to measure the altitude of the sun above the horizon ...
Alpha Sext = Alpha Sextantis
Taurus
Aldebaran = Alpha Tauri*
Elnath = Beta Tauri
Hyadum I = Gamma Tauri
Hyadum II = Delta-1 Tauri
Ain = Epsilon Tauri #
Zeta Tau = Zeta Tauri
Alcyone = Eta Tauri
Theta-1 Tau = Theta-1 Tauri & ...
altitude circle (NASA SP-7, 1965) = parallel of altitude altitude difference (NASA SP-7, 1965) In navigation, the difference between computed and observed altitudes, or between precomputed and sextant altitudes.
semidiameter correction A correction due to semidiamter, particularly that sextant altitude correction resulting from observation of the upper or lower limb of a celestial body, rather than the center of that body.
Commander Jim Lovell and LM Pilot Fred Haise were in the process of completing a checkout of Aquarius, their lunar lander; and CSM Pilot Jack Swigert was preparing to make some star sightings with his sextant.
Octans, the Octant (a forerunner of the sextant) is an Enlightenment-period instrument whose outline was constructed on the sky by the vivid imagination of the Abbé Lacaille. The constellation is quite large but totally undistinguished.
Many tests were performed over the 11 day mission, including tests of sextant calibration, attitude control, evaporator, navigation, rendezvous radar, thermal control system, and service module propulsion systems.
The angle formed between Polaris and the immediate northern horizon can be measured accurately using a device called a sextant. A sextant originally measured angles within a 1/6 slice of a circle (60o) and that's how it got its name.
[7893] beta Sextantis is a variable star classified as a blue-white main sequence dwarf, lying about 345 light-years from Earth. [7894] delta Sextantis is another blue-white dwarf, approximately 300 light-years distant.
for Star A and 11:26:46.3+03:00:22.8 for Star B, ICRS 2000.0) of Constellation Leo, the Lion -- south of Sigma, Iota, Theta (Coxa), and Delta Leonis (Zosma); west of Zavijava (Beta Virginis); north of Phi Leonis, and east of Alpha Sextantis.
Hevelius had continued to make naked-eye sightings with his sextant throughout his life, even though telescopes were available; it was perhaps to demonstrate the keenness of his eyes that he formed Sextans out of such faint stars, ...
Historically, these have been as simple as containing a sextant (for measuring the distance between stars) to as complex as Stonehenge (for measuring the seasons through the position of the sun's rising and setting).
The modern goup Sextans, the Sextant.
The Cup (of Bacchus ?) Crater and
the Crow Corvus are located between the Sea Serpent and the zodiacal groups Lion and Virgin.
The Serpent Holder Ophiuchus is busily struggling with the ...
Abbreviation: Sex
Genitive: Sextantis
Translation: The Sextant
Peoria Astronomical Society Sextans Page
Interactive star chart (Java applet) ...
Tycho Brahe used only a compass and a sextant to observe the stars.
Return to the StarChild Main Page
Go to Imagine the Universe! (A site for ages 14 and up.) ...
It required knowledge of the time at Greenwhich (longitude zero) when a cross staff or sextant determined that the Sun was passing local noon. For example, if the Sun passed local noon when it was 1 p.m.
Antares (Alpha Scorpii)
M80 cluster
Sculptor (Sculptoris) Scutum (Scuti) Serpens (Serpentis) Sextans (Sextantis) Taurus (Tauri)
Taurean system
Aldebaran (Alpha Tauri)
Gamma Tauri
T Tauri
Crab Nebula
Murasaki 312 ...
Pyxis(the compass), Reticulum(reticle), Sagitta(arrow), Sagittarius(archer), Scorpius(scorpion), Sculptor, Scutum(shield), Serpens(serpent), Sextans(sextant), Taurus the Bull, Telescopium(telescope), ...
An instrument, based on a quarter of a circle, employed to measure the altitude above the horizon of astronomical bodies. Eventually replaced by the sextant. [F88]
Quadrature ...
The choice of names for this constellation is significant because the octant was used to measure the position of Polaris innumerable times in the early years of celestial navigation. In later years, the octant was replaced by the sextant (which also ...
Since its first edition in 1767, The Nautical Almanac has given the precise positions of the Sun, Moon and planets to allow mariners to determine their position at sea from sightings made with a sextant.
more flat, metal, calibrated disks, attached so that both or all can rotate independently. For early navigators and astronomers it served as star chart, compass, clock, and calendar. As a navigational device it was eventually replaced by the sextant.
 See also: Earth, Star, Constellation, Time, Sun
|
