Delta² Lyrae
Encyclopedia
Delta2 Lyrae is a 4th magnitude star in the constellation Lyra, approximately 900 light years away from Earth
. It is a class M4II star, meaning it is a bright giant
star with a surface temperature under 3,500 kelvins. It shines with the light of 6,500 Sun
s, and has a radius of 200 solar radii, or 0.95 times the radius of Earth's orbit, though other measurements give an even larger radius of 1.3 astronomical unit
s.
It began life 75 million years ago as a bluish white B3 spectral type star of six solar mass
es, with a surface temperature between 11,000 and 25,000 kelvins. It now possesses a dead helium core, and is becoming an even larger giant. It is a semi-regular variable star
that has its brightness change by 0.2 magnitudes over an ill-defined period. Delta2 Lyrae was once thought to form a visual binary with the star Delta1 Lyrae, but it does not, only appearing to do so to the naked eye.
The spectral type of the nearby star system CCDM J18545+3654BC suggests that they are at the same distance as Delta2 Lyrae, which could mean that the three stars form a trinary star system. In this case, CCDM J18545+3654BC would be 24,000 AU away from Delta2 Lyrae, and it would take 24,000 years for it to make an orbit. The two stars in the CCDM J18545+3654BC system take at least 10,500 years to make an orbit and are separated by 600AU.
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
. It is a class M4II star, meaning it is a bright giant
Bright giant
The luminosity class II in the Yerkes spectral classification is given to bright giants. These are stars which straddle the boundary between giants and supergiants, and the classification is in general given to giant stars with exceptionally high luminosity, but which are not sufficiently bright...
star with a surface temperature under 3,500 kelvins. It shines with the light of 6,500 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...
s, and has a radius of 200 solar radii, or 0.95 times the radius of Earth's orbit, though other measurements give an even larger radius of 1.3 astronomical unit
Astronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
s.
It began life 75 million years ago as a bluish white B3 spectral type star of six solar mass
Solar mass
The solar mass , , is a standard unit of mass in astronomy, used to indicate the masses of other stars and galaxies...
es, with a surface temperature between 11,000 and 25,000 kelvins. It now possesses a dead helium core, and is becoming an even larger giant. It is a semi-regular variable star
Variable star
A star is classified as variable if its apparent magnitude as seen from Earth changes over time, whether the changes are due to variations in the star's actual luminosity, or to variations in the amount of the star's light that is blocked from reaching Earth...
that has its brightness change by 0.2 magnitudes over an ill-defined period. Delta2 Lyrae was once thought to form a visual binary with the star Delta1 Lyrae, but it does not, only appearing to do so to the naked eye.
The spectral type of the nearby star system CCDM J18545+3654BC suggests that they are at the same distance as Delta2 Lyrae, which could mean that the three stars form a trinary star system. In this case, CCDM J18545+3654BC would be 24,000 AU away from Delta2 Lyrae, and it would take 24,000 years for it to make an orbit. The two stars in the CCDM J18545+3654BC system take at least 10,500 years to make an orbit and are separated by 600AU.