title: HD 10800
text: # HD 10800
  
  HD 10800, also known as HR 512 or Gliese 67.1, is a triple star located in the southern circumpolar constellation Octans. It has a combined apparent magnitude of 5.87, allowing it to be faintly seen with the naked eye. The system is relatively close at a distance of 88.1 light years but is drifting closer with a heliocentric radial velocity −1.1 km/s.
  
  The system has a blended spectral classification of G1 V, indicating an ordinary G-type main-sequence star. The primary is a spectroscopic binary consisting of a G-type and K-type star circling around each other in 19 days. HD 10800B has a class of G2 V, the same spectral class as our own Sun. The AB pair take 1.7 years to orbit each other.
  
  ## HD 10800A
  
  The primary (Aa) has 109% the mass of the Sun and a radius 1.1 times that of the Sun. It radiates at 1.82 times the luminosity of the Sun from its photosphere at an effective temperature of 5,802 K, giving a yellow hue. HD 10800A has a metallicity 81% that of the Sun, making it slightly metal deficient. At an age of 5 billion years, it spins with a projected rotational velocity of 7 km/s. The close companion (Ab) has a mass 69% that of the Sun.
  
  ## HD 10800B
  
  HD 10800B, the slightly distant companion, has the same mass of the Sun but is slightly cooler (37 K difference) and dimmer, with a luminosity 98% that of the Sun. The object is only marginally older than the Sun at an age of 4.8 billion years.
  
  