View example sentences, synonyms and word forms for Arcsecond.
Arcsecond meaning
A unit of angle; 1/60th of an arcminute, or 1/3600th of a degree.
Synonyms of Arcsecond
Example sentences (11)
A second of arc, arcsecond (arcsec), or arc second is of an arcminute, of a degree, of a turn, and (about ) of a radian.
If a full moon is present, the sky brightness increases to about 18 magnitude/sq. arcsecond depending on local atmospheric transparency, 40 times brighter than the darkest sky.
In densely populated areas a sky brightness of 17 magnitude/sq. arcsecond is not uncommon, or as much as 100 times brighter than is natural.
It is the distance at which the mean radius of the Earth's orbit would subtend an angle of one arcsecond.
The amount of airglow and zodiacal light is quite variable (depending, amongst other things on sunspot activity and the Solar cycle ) but given optimal conditions the darkest possible sky has a brightness of about 22 magnitude/square arcsecond.
The angle SDE is one arcsecond ( 1 3600 of a degree) so by definition D is a point in space at a distance of one parsec from the Sun.
The dwarf planet Pluto has proven difficult to resolve because its angular diameter is about 0.1 arcsecond.
The notation using the "arc-" prefix avoids such confusion, though "arcsec" for arcsecant can be confused with " arcsecond ".
The positions of most are known to 0.001 arcsecond or better, which is orders of magnitude more precise than the best optical measurements.
These small angles may also be written in milliarcseconds (mas), or thousandths of an arcsecond.
The standard symbol for the arcsecond is the double prime (″) (U+2033), though a double quote (") (U+0022) is commonly used where only ASCII characters are permitted.