Tycho G
Encyclopedia
Tycho G is the surviving binary companion star of the SN 1572
supernova
event.
The star is located about 7500 light-year
s away in the constellation Cassiopeia
. It is a subgiant, similar to our Sun in luminosity and color but more evolved.
Tycho G is still close to the center of the supernova remnant and had triggered once the explosion of its binary companion white dwarf
star by contributing mass to it.
is often called "Tycho's supernova", named after Tycho Brahe
who observed the "new star" in 1572.
The postfix "G" originates from the candidate companion stars considered, labelled Tycho A to Tycho V.
SN 1572
SN 1572 , "B Cassiopeiae" , or 3C 10 was a supernova of Type Ia in the constellation Cassiopeia, one of about eight supernovae visible to the naked eye in historical records...
supernova
Supernova
A supernova is a stellar explosion that is more energetic than a nova. It is pronounced with the plural supernovae or supernovas. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months...
event.
The star is located about 7500 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 away in the constellation Cassiopeia
Cassiopeia (constellation)
Cassiopeia is a constellation in the northern sky, named after the vain queen Cassiopeia in Greek mythology, who boasted about her unrivalled beauty. Cassiopea was one of the 48 constellations listed by the 2nd century Greek astronomer Ptolemy, and it remains one of the 88 modern constellations today...
. It is a subgiant, similar to our Sun in luminosity and color but more evolved.
Tycho G is still close to the center of the supernova remnant and had triggered once the explosion of its binary companion white dwarf
White dwarf
A white dwarf, also called a degenerate dwarf, is a small star composed mostly of electron-degenerate matter. They are very dense; a white dwarf's mass is comparable to that of the Sun and its volume is comparable to that of the Earth. Its faint luminosity comes from the emission of stored...
star by contributing mass to it.
Evidence for companion hypothesis
- Tycho G is traveling at a rate of 136 km/s, which is more than four times faster than the mean velocity of other stars in its stellar neighbourhood.
- Tycho G's metallicityMetallicityIn astronomy and physical cosmology, the metallicity of an object is the proportion of its matter made up of chemical elements other than hydrogen and helium...
is about 3 times higher than the mean metallicity of other stars in its stellar neighbourhood.
Origin of the name
The supernova SN 1572SN 1572
SN 1572 , "B Cassiopeiae" , or 3C 10 was a supernova of Type Ia in the constellation Cassiopeia, one of about eight supernovae visible to the naked eye in historical records...
is often called "Tycho's supernova", named after Tycho Brahe
Tycho Brahe
Tycho Brahe , born Tyge Ottesen Brahe, was a Danish nobleman known for his accurate and comprehensive astronomical and planetary observations...
who observed the "new star" in 1572.
The postfix "G" originates from the candidate companion stars considered, labelled Tycho A to Tycho V.
External links
- Discovery of the binary companion of Tycho Brahe's supernova
- http://jumk.de/astronomie/special-stars/tycho-g.shtml
- http://www.skyandtelescope.com/news/3309696.html?page=1&c=y