          hd 12661 is a g-type main sequence star in the northern constellation of aries. the star is slightly larger and more massive than the sun, with an estimated age of seven billion years. it has two known extrasolar planets. ==properties== the apparent visual magnitude of this star is 7.42, making it too faint to be viewed by the naked eye even under ideal viewing conditions. however, it can be readily observed using a small telescope with an aperture of  or more. parallax measurements of hd 12661 place it at a distance of about  from the earth, with a margin of error of Â±2 light years. it has a stellar classification of g6&nbsp;v, indicating that it is a main sequence star that is generating energy through the thermonuclear fusion of hydrogen at its core. the effective temperature of the star's outer envelope is about 5,754&nbsp;k, giving it the characteristic yellow hue of a g-type star. based on stellar models, estimates of the radius of this star range from 107% to 112% times sun's radius, while the mass is likely in the range from 107% to 110% of the sun's mass. as a star ages it slows its rotation and diminishes the amount of magnetic activity in its chromosphere. hence the measured emission from the chromosphere can be used to estimate the age of a star, particularly for f and g-type dwarf stars with an age of less than two billion years. however, this technique becomes less accurate for ages beyond about 5.6 billion years. based upon the chromosphere emission of hd 12661, it is older than the sun with an estimated age of roughly seven billion years. it has a low projected rotational velocity of 1.20&nbsp;km/s, consistent 
Aries_(constellation) G-type_main-sequence_stars Henry_Draper_Catalogue_objects Hipparcos_objects Planetary_systems_with_two_confirmed_planets