Search results
Results From The WOW.Com Content Network
The amount of shift is quite small, even for the nearest stars, measuring 1 arcsecond for an object at 1 parsec's distance (3.26 light-years), and thereafter decreasing in angular amount as the distance increases. Astronomers usually express distances in units of parsecs (parallax arcseconds); light-years are used in popular media.
The quasar's redshift indicates that it is located about 8 billion light years from Earth, while the lensing galaxy is at a distance of 400 million light years. The apparent dimensions of the entire foreground galaxy are 0.87 × 0.34 arcminutes, [7] while the apparent dimension of the cross in its centre accounts for only 1.6 × 1.6 arcseconds.
The first is the direction of the proper motion on the celestial sphere (with 0 degrees meaning the motion is north, 90 degrees meaning the motion is east, (left on most sky maps and space telescope images) and so on), and the second is its magnitude, typically expressed in arcseconds per year (symbols: arcsec/yr, as/yr, ″/yr, ″ yr −1) or ...
A parsec is the distance from the Sun to an astronomical object that has a parallax angle of one arcsecond (not to scale). The parsec (symbol: pc) is a unit of length used to measure the large distances to astronomical objects outside the Solar System, approximately equal to 3.26 light-years or 206,265 astronomical units (AU), i.e. 30.9 trillion kilometres (19.2 trillion miles).
The centre of the Milky Way is about 26 000 light-years away. [35] [36] 1 × 10 5 ly: The Milky Way is about 100 000 light-years across. 1.65 × 10 5 ly: R136a1, in the Large Magellanic Cloud, the most luminous star known at 8.7 million times the luminosity of the Sun, has an apparent magnitude 12.77, just brighter than 3C 273. 10 6: 2.5 × 10 6 ly
Stellar parallax measures are given in the tiny units of arcseconds, or even in thousandths of arcseconds (milliarcseconds). The distance unit parsec is defined as the length of the leg of a right triangle adjacent to the angle of one arcsecond at one vertex , where the other leg is 1 AU long.
Epsilon Eridani has a high proper motion, moving −0.976 arcseconds per year in right ascension (the celestial equivalent of longitude) and 0.018 arcseconds per year in declination (celestial latitude), for a combined total of 0.962 arcseconds per year. [1] [note 5] The star has a radial velocity of +15.5 km/s (35,000 mph) (away from the Sun ...
At a distance of 14.1 light-years it is the third closest of its type of star after Sirius B and Procyon B, in that order. [ 10 ] [ 11 ] Discovered in 1917 by Dutch–American astronomer Adriaan van Maanen , [ 12 ] Van Maanen 2 was the third white dwarf identified, after 40 Eridani B and Sirius B, and the first solitary example.