What are the units of astronomical measurement?
104203
The angstrom is one unit of measure.\nAstronomical Unit is another. (Au)\nParsec is another (PC)
621287
International System of units\n\nfor length its the meter
992153
the listing is here:\n  http://en.wikipedia.org/wiki/Conversion_of_units\nhere is a calculator\nhttp://www.onlineconversion.com/
796855
if you mean an ellipse....\n\narea is equal to pi * minor radius * major radius
1067172
Units are arbitrary, but once chosen need to be kept as a constant reference to allow comparison of results over time. This is a challenge, because even things like measurement precision  change.\n\nThe original metre for instance was a reference bar of platinum held in Sevres, France - its length was originally chosen to be one ten millionth of the distance from the Equator to the North Pole on a line through Paris. Similarly for all other units.\n\nThese days, most units have been redefined in terms of unchanging physical phenomena that can be reproduced in any standards lab without the need for a special reference bit of metal. So the metre is now defined as the distance travelled by light in 1/299,792,458 seconds. This means it is a tiny bit different to the original metre but will never change.\n\nThe notable exception is mass. The kilogram is defined as being equal to the mass of the international prototype of the kilogram. This prototype is a lump of platinum iridium alloy held in Paris. The kilogram is the only SI unit based on a reference prototype.
89835
In terms of mass.\nThe SI unit for mass is the kilogram (kg).\n\nDo not confuse mass with weight, they are not the same thing.  The mass of an object is constant throughout the universe where as weight is a vector force that depends on the gravitational field around the object.  It is unfortunate that these two words are used interchangably sometimes.
17260
The hour was originally defined in ancient civilisations (including those of Egypt, Sumeria, India and China) as either one twelfth of the time between sunrise and sunset or one twenty-fourth of a full day. In either case the division reflected the widespread use of a duodecimal numbering system (counting with each thumb the spaces between the joints of the other finger on the same hand, i.e. 3 x 4 = 12) and the equally widespread tendency to make analogies among sets of data (12 months, 12 zodiacal signs, 12 main compass points, 12 hours, a dozen).
43195
Physics, major science dealing with the fundamental constituents of the universe, the forces they exert on one another, and the effects of these forces. \n\nMeasurement, finding the size or amount of some quantity, and expressing it as a number of defined units.All measurement is based on a comparison. In general, the thing to be measured is compared with something that has already been calibrated, or measured against a known reference. However, a measurement is not complete unless it includes a statement of its uncertainty, or the confidence one can have in it.\nUnits of Weight and Measurement\nImperial System\nAMOUNT NAME \nAngular or Circular Measure \n60 seconds = 1 minute (min) \n60 minutes = 1 degree \n30 degrees = 1 zodiac sign \n57.2958 degrees = 1 radian \n90 degrees = 1 quadrant or right angle \n360 degrees = 1 circle \nCubic Measure (Volume) \n1,728 cubic inches (cu in) = 1 cubic foot (cu ft) \n27 cubic feet = 1 cubic yard (cu yd) \n231 cubic inches = 1 US gallon (gal) \n277.27 cubic inches = 1 British imperial gallon (i gal) \n2,150.42 cubic inches = 1 US bushel (bu) \n2,219.36 cubic inches = 1 British imperial bushel (i bu) \nDry Measure (Capacity) \n2 pints = 1 quart \n8 quarts = 1 peck (pk) \n4 pecks = 1 bushel \nLinear Measure (Length) \n1,000 mils = 1 inch (in) \n12 inches = 1 foot (ft) \n3 feet = 1 yard (yd) \n5.5 yards = 1 rod (rd) \n40 rods = 1 furlong (fur) \n8 furlongs = 1 mile (mi) \n5,280 feet = 1 mile \n3 miles = 1 league (l) \nLiquid Measure (Capacity) \n4 fluid ounces (fl oz) = 1 gill (gi) \n4 gills = 1 pint (pt) \n2 pints = 1 quart (qt) \n4 quarts = 1 gallon (gal) \nMariners’ Measure \n6 feet = 1 fathom (fath) \n120 fathoms = 1 cable’s length (US Navy) \n1,852 metres = 1 nautical mile (n mi) \n1 nautical mile per hour (n mph) = 1 knot (k) \nPaper Measure \n25 sheets = 1 quire (qr) \n20 quires = 1 standard ream (rm) \n516 sheets = 1 printers’ ream \n2 reams = 1 bundle (bdl) \n4 bundles = 1 case (c) \nPrinters’ Measure (Typography) \n0.013837 inches = 1 point \n12 points = 1 pica \nSquare Measure (Area) \n144 square inches (sq in) = 1 square foot (sq ft) \n9 square feet = 1 square yard (sq yd) \n30.25 square yards = 1 square rod (sq rd) \n160 square rods = 1 acre \n640 acres = 1 square mile (sq mi) \nSurveyors’ Measure \n7.92 inches = 1 link (li) \n66 feet = 1 chain \n80 chains = 1 mile \nWood Measure \n144 cubic inches (1' x 1' x 1'') = 1 board foot (bd ft) \n16 cubic feet (4' x 4' x 1') = 1 cord foot (cd ft) \n8 cord feet = 1 cord (cd) \nWEIGHTS \nWeight (Apothecaries’) \n20 grains = 1 scruple (s ap) \n3 scruples = 1 dram (dr ap) \n8 drams = 1 ounce (oz ap) \n12 ounces = 1 pound (lb ap) \nWeight (Avoirdupois) \n27.3438 grains = 1 dram (dr) \n16 drams = 1 ounce (oz) \n16 ounces = 1 pound (lb) \n14 pounds = 1 stone \n100 pounds = 1 hundredweight (cwt) \n8 stones = 1 long hundredweight \n(l cwt) \n2,000 pounds = 1 short ton (ST) \n2,240 pounds = 1 long ton (LT) or 20 (l cwt) \nWeight (Troy) \n24 grains = 1 pennyweight (dwt) \n20 pennyweights = 1 ounce (oz t) \n12 ounces = 1 pound (lb t) \n\nMiscellaneous Units\nWEIGHT/MEASURE UNITS \nAbsolute zero = -273.15o C (-459.67o F) \n1 atmosphere = 760 mm of mercury \n1 cup = 10 fluid ounces \n1 carat (international) = 200 milligrams (gem weight) \n1 megaton = 1,000,000 tons \n3 teaspoons = 1 tablespoon \n1 angstrom unit = 0.1 nanometre \n1 bolt of cloth = 40 yards \n1 gross = 12 dozen, or 144 \n1 light-year = 9.46 x 1012 km \n(5.88 x 1012 mi) \n1 tablespoon = 1/2 fluid ounce
8760
None, the two are not related. Earth's rotation is a measure of time and light years are a measure of distance.
535160
what do you want to calculate? gravitation? emission? something else?
791590
E = m x c^2,\nso \n\nmass = Energy / c^2 (speed of light squared)
348309
Look at the website   http://www.heavens-above.com/  \n\nPlug in your location info (bookmark it) and you'll get all the local astronomical information you need.
729339
About .39 astronomical units.
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No, you don't.  You'll be counting fringes, and backworking calculations.\n\nHow big of a distance?\n\nYou'll be in units of nm (typical interferometry).
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Try using this link for converting distances into different units.
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persec is the largest unit of distance and is 3.26 times of a light year.Whereas one light year is equal to 9.45X10^12 km ,one persec is equal to 30.84X 10^12 km.This is the reason for using persec
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The offical SI base unit would be meters. \n\nProbably centimeters works best for an average plant.