3C 66A
Encyclopedia
3C 66A is a Blazar
located in the constellation
Andromeda
.
The "distance" of a far away galaxy depends on what distance measurement
you use. With a redshift
of 0.444, light from this active galaxy
is estimated to have taken around 4.5 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 5.4 billion light-year
s (1647 Mpc
). Even at this great distance this blazar has an apparent magnitude
of about 15.5.
3C 66A underwent an optical outburst in 2007 August, as monitored by the Tuorla blazar monitoring program. The event was monitored by the Whole Earth Blazar Telescope
project.
Blazar
A blazar is a very compact quasar associated with a presumed supermassive black hole at the center of an active, giant elliptical galaxy...
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....
Andromeda
Andromeda (constellation)
Andromeda is a constellation in the northern sky. It is named after Andromeda, the princess in the Greek legend of Perseus who was chained to a rock to be eaten by the sea monster Cetus...
.
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 0.444, 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 4.5 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 5.4 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 (1647 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 ....
). Even at this great distance this blazar has an apparent 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...
of about 15.5.
3C 66A underwent an optical outburst in 2007 August, as monitored by the Tuorla blazar monitoring program. The event was monitored by the Whole Earth Blazar Telescope
Whole Earth Blazar Telescope
The Whole Earth Blazar Telescope is an international consortium of astronomers created in 1997, with the aim to study a particular category of Active Galactic Nuclei called blazars, which are characterized by strong and fast brightness variability, on time scales down to hours or less.This...
project.