stars of spectral class f or cooler are a type of star found on the lower end of the main sequence, based on its mass.
stars of spectral class f or cooler are a type of star found on the lower end of the main sequence, based on its mass.
which is a type of star found on the lower end of the main sequence, based on its mass?
stars of spectral class f or cooler
the main sequence is sometimes divided into upper and lower parts, based on the dominant process that a star uses to generate energy. stars below about 1.5 times the mass of the sun () primarily fuse hydrogen atoms together in a series of stages to form helium, a sequence called the proton–proton chain. above this mass, in the upper main sequence, the nuclear fusion process mainly uses atoms of carbon, nitrogen and oxygen as intermediaries in the cno cycle that produces helium from hydrogen atoms. main-sequence stars with more than two solar masses undergo convection in their core regions, which acts to stir up the newly created helium and maintain the proportion of fuel needed for fusion to occur. below this mass, stars have cores that are entirely radiative with convective zones near the surface. with decreasing stellar mass, the proportion of the star forming a convective envelope steadily increases. main-sequence stars below undergo convection throughout their mass. when core convection does not occur, a helium-rich core develops surrounded by an outer layer of hydrogen.
main sequence
six star systems have been found to contain exoplanets, of which two were discovered by the doppler method and four by the transit method. 6 lyncis, an orange subgiant that spent much of its life as an a-type or f-type main sequence star, is orbited by a planet with a minimum mass of 2.4 jupiter masses and an orbital period of 899 days. hd 75898 is a 3.8 ± 0.8 billion-year-old yellow star of spectral type g0v that has just begun expanding and cooling off the main sequence. it has a planet at least 2.51 times as massive as jupiter orbiting with a period of around 418 days. the centre of mass of the system is accelerating, indicating there is a third, more distant, component at least the size of jupiter. three star systems were found to have planets that were observed by the xo telescope in hawaii as they passed in front of them. xo-2 is a binary star system, both the stars of which are slightly less massive and cooler than the sun and have planetary companions: xo-2s has a saturn-mass planet at 0.13 au distance with a period of around 18 days, and one a little more massive than jupiter at a distance of 0.48 au and with a period of around 120 days, and xo-2n has a hot jupiter with around half jupiter's mass that has an orbit of only 2.6 days. xo-4 is an f-type main sequence star that is a little hotter and more massive than the sun that has a hot jupiter orbiting with a period of around 4.1 days. xo-5 is a sun-like star with a hot jupiter about as massive as jupiter that takes around 4.2 days to complete an orbit. wasp-13, a sun-like star that has begun to swell and cool off the main sequence, had a transiting planet discovered by the superwasp program in 2009. the planet is around half as massive as jupiter and takes 4.35 days to complete a revolution.
lynx (constellation)