3C 147
Encyclopedia
3C 147 is a compact steep-spectrum (CSS) quasar
that was discovered in 1964. It is located in the constellation
Auriga
not far in the sky from the 5th magnitude
star Omicron Aurigae
.
The "distance" of a far away galaxy depends on what distance measurement
you use. With a redshift
of 0.545, light from this active galaxy
is estimated to have taken around 5.1 billion years to reach us. But as a result of the expansion of the Universe, the present (co-moving) distance to this galaxy is about 6.4 billion light-year
s (1974 Mpc
).
Very Long Baseline Array
(VLBA) observations have identified a complex central region that is dominated by two bright components, A and B. The separation between the two central components of the source seems to be increasing with an apparent velocity (superluminal motion
) of 1.2 ± 0.4 c
.
Quasar
A quasi-stellar radio source is a very energetic and distant active galactic nucleus. Quasars are extremely luminous and were first identified as being high redshift sources of electromagnetic energy, including radio waves and visible light, that were point-like, similar to stars, rather than...
that was discovered in 1964. It is located in the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
Auriga
Auriga (constellation)
Auriga is a constellation in the northern sky. Its name is Latin for 'charioteer' and its stars form a shape that has been associated with the pointed helmet of a charioteer. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains among the 88 modern...
not far in the sky from the 5th magnitude
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...
star Omicron Aurigae
Omicron Aurigae
Omicron Aurigae is a star in the constellation Auriga. Its apparent magnitude is 5.46. It is approximately 482 light-years away from Earth, which makes it barely visible to the naked eye despite the fact that it gives off more energy than Sirius, the brightest star in the sky. ο Aurigae is a...
.
The "distance" of a far away galaxy depends on what distance measurement
Distance measures (cosmology)
Distance measures are used in physical cosmology to give a natural notion of the distance between two objects or events in the universe. They are often used to tie some observable quantity to another quantity that is not directly...
you use. With a redshift
Redshift
In physics , redshift happens when light seen coming from an object is proportionally increased in wavelength, or shifted to the red end of the spectrum...
of 0.545, light from this active galaxy
Active galactic nucleus
An active galactic nucleus is a compact region at the centre of a galaxy that has a much higher than normal luminosity over at least some portion, and possibly all, of the electromagnetic spectrum. Such excess emission has been observed in the radio, infrared, optical, ultra-violet, X-ray and...
is estimated to have taken around 5.1 billion years to reach us. But as a result of the expansion of the Universe, the present (co-moving) distance to this galaxy is about 6.4 billion light-year
Light-year
A light-year, also light year or lightyear is a unit of length, equal to just under 10 trillion kilometres...
s (1974 Mpc
Parsec
The parsec is a unit of length used in astronomy. It is about 3.26 light-years, or just under 31 trillion kilometres ....
).
Very Long Baseline Array
Very Long Baseline Array
The Very Long Baseline Array is a system of ten radio telescopes controlled remotely from the Array Operations Center in Socorro, New Mexico by the National Radio Astronomy Observatory. The array works together as the world's largest dedicated, full-time astronomical instrument using the...
(VLBA) observations have identified a complex central region that is dominated by two bright components, A and B. The separation between the two central components of the source seems to be increasing with an apparent velocity (superluminal motion
Superluminal motion
In astronomy, superluminal motion is the apparently faster-than-light motion seen in someradio galaxies, quasars and recently also in some galactic sources called microquasars...
) of 1.2 ± 0.4 c
Speed of light
The speed of light in vacuum, usually denoted by c, is a physical constant important in many areas of physics. Its value is 299,792,458 metres per second, a figure that is exact since the length of the metre is defined from this constant and the international standard for time...
.
External links
- Wikisky image of 3C 147 (PGC 2355407)