Delta Trianguli
Encyclopedia
Delta Trianguli is a spectroscopic binary star system
approximately 35 ly away in the constellation
of Triangulum
. The primary star
is a yellow dwarf
, while the secondary star is thought to be an orange dwarf
. The system is one part of a moving group of stars with Zeta Herculis.
star
and with a mass higher than the Sun
. The spectral characteristics of the smaller companion Delta Trianguli B are not well determined since the close orbit makes observations difficult, although it may be an orange dwarf
of spectral type
K3V. This system is part of the Zeta Herculis stellar moving group.
The Delta Trianguli stars orbit their center of mass
. Star A orbits approximately 0.045 AU
from the center and star B orbits approximately 0.065 AU from the center. They orbit each other every 10.02 day
s in a nearly circular orbit; the eccentricity of the orbit is only 0.020. The orbit is inclined 167° to our line of sight.
A 2008 search for a tertiary companion to this system using an adaptive optics
system on the VLT
proved unsuccessful.
Star system
A star system or stellar system is a small number of stars which orbit each other, bound by gravitational attraction. A large number of stars bound by gravitation is generally called a star cluster or galaxy, although, broadly speaking, they are also star systems.-Binary star systems:A stellar...
approximately 35 ly away 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....
of Triangulum
Triangulum
Triangulum is a small constellation in the northern sky. Its name is Latin for triangle, and it should not be confused with Triangulum Australe in the southern sky. Its name derives from its three brightest stars, of third and fourth magnitude, which form a nearly isosceles long and narrow triangle...
. The primary star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
is a yellow dwarf
Yellow dwarf
A G-type main-sequence star , often called a yellow dwarf, is a main-sequence star of spectral type G and luminosity class V. Such a star has about 0.8 to 1.2 solar masses and surface temperature of between 5,300 and 6,000 K., Tables VII, VIII...
, while the secondary star is thought to be an orange dwarf
Orange dwarf
A K-type main-sequence star , also referred to orange dwarf, are main-sequence stars of spectral type K and luminosity class V. These stars are intermediate in size between red M-type main-sequence stars and yellow G-type main-sequence stars...
. The system is one part of a moving group of stars with Zeta Herculis.
Stellar components
Delta Trianguli A is a yellow dwarfYellow dwarf
A G-type main-sequence star , often called a yellow dwarf, is a main-sequence star of spectral type G and luminosity class V. Such a star has about 0.8 to 1.2 solar masses and surface temperature of between 5,300 and 6,000 K., Tables VII, VIII...
star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
and with a mass higher than the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
. The spectral characteristics of the smaller companion Delta Trianguli B are not well determined since the close orbit makes observations difficult, although it may be an orange dwarf
Orange dwarf
A K-type main-sequence star , also referred to orange dwarf, are main-sequence stars of spectral type K and luminosity class V. These stars are intermediate in size between red M-type main-sequence stars and yellow G-type main-sequence stars...
of spectral type
Stellar classification
In astronomy, stellar classification is a classification of stars based on their spectral characteristics. The spectral class of a star is a designated class of a star describing the ionization of its chromosphere, what atomic excitations are most prominent in the light, giving an objective measure...
K3V. This system is part of the Zeta Herculis stellar moving group.
The Delta Trianguli stars orbit their center of mass
Center of mass
In physics, the center of mass or barycenter of a system is the average location of all of its mass. In the case of a rigid body, the position of the center of mass is fixed in relation to the body...
. Star A orbits approximately 0.045 AU
Astronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
from the center and star B orbits approximately 0.065 AU from the center. They orbit each other every 10.02 day
Day
A day is a unit of time, commonly defined as an interval equal to 24 hours. It also can mean that portion of the full day during which a location is illuminated by the light of the sun...
s in a nearly circular orbit; the eccentricity of the orbit is only 0.020. The orbit is inclined 167° to our line of sight.
A 2008 search for a tertiary companion to this system using an adaptive optics
Adaptive optics
Adaptive optics is a technology used to improve the performance of optical systems by reducing the effect of wavefront distortions. It is used in astronomical telescopes and laser communication systems to remove the effects of atmospheric distortion, and in retinal imaging systems to reduce the...
system on the VLT
VLT
VLT may stand for:* Very Large Telescope, a system of four large optical telescopes organized in an array formation, located in northern Chile...
proved unsuccessful.