For nearby astronomical objects ( such as stars in our galaxy ) luminosity distance D < sub > L </ sub > is almost identical to the real distance to the object, because spacetime within our galaxy is almost Euclidean.

For this reason, astronomical position determination – measuring the direction of the plumbline by astronomical means – works fairly well provided an ellipsoidal model of the figure of the Earth is used.

For some lunar calendars, such as the Chinese calendar, the first day of a month is the day when an astronomical new moon occurs in a particular time zone.

For the astronomer's sextant, see Sextant ( astronomical ).

For the year ( Y ) astronomical year numbering is used, thus 1 BC is 0, 2 BC is − 1, and 4713 BC is − 4712.

For accurate astronomical work on land, it was usual to observe sidereal time rather than solar time to measure mean solar time, because the observations of ' fixed ' stars could be measured and reduced more accurately than observations of the Sun ( in spite of the need to make various small compensations, for refraction, aberration, precession, nutation and proper motion ).

For decades after the discovery of GRBs, astronomers searched for a counterpart at other wavelengths: i. e., any astronomical object in positional coincidence with a recently observed burst.

For large astronomical bodies which are near-spherical due to self-gravitation, the tidal distortion produces a slightly prolate spheroid-i. e., an axially symmetric ellipsoid that is elongated along its major axis.

: For the terms " civil sunset " and " astronomical sunset ", see Twilight # Definitions

For typical seeing, the practical resolution limits are at mirror sizes well within existing mechanical limits, at a mirror diameter equal to the astronomical seeing parameter r < sub > 0 </ sub >-about 20 cm in diameter for visible observations under good conditions.

For geographical and cartographical poles on astronomical bodies other than Earth, see Poles of astronomical bodies.

For many years, a growing problem in astronomical research ( as in other academic disciplines ) was that the number of papers published in the major astronomical journals was increasing steadily, meaning astronomers were able to read less and less of the latest research findings.

For example, spectrograph and spectroscope have basically the same meaning, and in an astronomical context metallicity and abundance are also synonymous.

For ten years he actively participated in the work of the Astronomical Society, contributing papers on the theory of astronomical instruments, the aberration of light, the differential sextant, and the convertible pendulum.

For most of its orbit it is even farther from the Sun than at present, with its aphelion estimated at 960 astronomical units ( 32 times Neptune's distance ), making it one of the most distant known objects in the Solar System other than long-period comets.

For example, the Guide Star Catalog II has entries on over 998 million distinct astronomical objects.

For example, an Earth-like planet at 1. 25 astronomical units from α Cen A ( with a revolution period of 1. 34 years ) would get Sun-like illumination from its primary, and α Cen B would appear 5. 7 to 8. 6 magnitudes dimmer (− 21. 0 to − 18. 2 ), 190 to 2700 times dimmer than α Cen A but still 2100 to 150 times brighter than the full Moon.

For placements where light pollution is of prime importance, such as an astronomical observatory parking lot, or a large city nearby an astronomical observatory, low pressure sodium is preferred.

For astronomical uses, reticles could be simple crosshair designs or more elaborate designs for special purposes.

For his applications of IR detectors to astronomy, Coblentz is regarded as the founder of astronomical infrared spectroscopy.

For purposes of this explanation, this percentage is referred to as the State's `` unadjusted Federal share ''.

For purposes of sample selection only ( individual tests were given later ) we obtained group test scores of reading achievement and intelligence from school records of the entire third-grade population in each school system.

For expository purposes, this is best treated as a model which spells out the conditions under which an important industry affected with the public interest would find it profitable to raise wages even in the absence of union pressures for higher wages.

For the purposes of setting the product price, the industry behaves as a single entity.

For the purposes of this discussion, the problem of relative prices is encompassed in these two variables, since GNP includes other prices.

For our present purposes we assume that the sole subject of bargaining is the basic wage rate ( not including productivity improvement factors or cost-of-living adjustments ), and it is this basic wage rate which determines the level of costs.

'' For present purposes it may be assumed that this charge so narrowly limited speech as to violate the federal Constitution.

For all practical purposes, the West stands disunited, undedicated, and unprepared for the tasks of world leadership.

For their purposes, oxygen and other gases were not drawn from the surrounding atmosphere through the medium of lungs but sustained artificially by solution in their shells.

For the purposes of the treaty system, Antarctica is defined as all of the land and ice shelves south of 60 ° S latitude.

For geopolitical purposes, the Sinai Peninsula of Egypt – east of the Suez Canal – is often considered part of Africa.

For socket numbers, a few well-known numbers were reserved for special purposes specific to the AppleTalk protocol itself.

For example, letters 1, 5, and 8 contain a discussion on the question, whether the use of a piece of metal with the figure of a lion, as a talisman, is permitted by Jewish law for medicinal purposes, or is prohibited as idolatrous.

For administrative purposes the archipelago constitutes the comune of Favignana in the Province of Trapani.

For comparison purposes that is approximately the same size as Aylesbury, Carlisle, Guildford or Scunthorpe urban areas.

For commercial purposes, it is derived primarily from Gelidium amansii.

For statistical purposes, Baker is grouped with the United States Minor Outlying Islands.

For purposes of scoring and reference, each player is identified by one of the points of the compass and thus North and South play against East and West.

For calendric purposes, Bede made a new calculation of the age of the world since the creation, which he dated as 3952 BC.

For scoring purposes, a standing eight count is treated as a knockdown.

For all practical purposes that was the Baltic language until 1919.

For most purposes, most jurisdictions, including the U. S. federal system and most states, have merged the two courts.

For purposes of international communication and trade, the official names of the chemical elements both ancient and more recently recognized are decided by the International Union of Pure and Applied Chemistry ( IUPAC ), which has decided on a sort of international English language, drawing on traditional English names even when an element's chemical symbol is based on a Latin or other traditional word, for example adopting " gold " rather than " aurum " as the name for the 79th element ( Au ).

For international banks, including the 55 member central banks of the Bank for International Settlements, the threshold is 8 % ( see the Basel Capital Accords ) of risk-adjusted assets, whereby certain assets ( such as government bonds ) are considered to have lower risk and are either partially or fully excluded from total assets for the purposes of calculating capital adequacy.

For enumeration purposes the country is demarcated into 4, 042 enumeration areas.