IC 4406

(Hubble Telescope, NASA) Right ascension (RA; symbol α: Greek letter alpha) is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. ... In astronomy, declination (dec) is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. ... Brightness is an attribute of visual perception in which a source appears to emit a given amount of light. ... The distance between two points is the length of a straight line segment between them. ... Light Years is also the American name of the Rene Laloux animated film Gandahar. ... For the geometric term, see diameter. ... A second of arc or arcsecond is a unit of angular measurement which comprises one-sixtieth of an arcminute, or 1/3600 of a degree of arc or 1/1296000 ≈ 7. ... Light Years is also the American name of the Rene Laloux animated film Gandahar. ... Orion is a remarkable constellation, visible from most places on the globe at one time or another during the year. ... Lupus (Latin for Wolf) is a southern constellation. ...