main sequence
Hydrogen-burning stellar stage
The main sequence is the band on a stellar classification diagram where most stars fall, including our sun.
Stars on the main sequence are in their longest, most stable phase, fusing hydrogen into helium in their cores.
Our sun will remain on the main sequence for another five billion years.
A star's position along the main sequence depends on its mass—heavier stars burn hotter and brighter but exhaust their fuel faster.
Intrinsic brightness of source
- fusionJoining into unity
- dwarfDiminutive folkloric being
- giantBeing of huge size
- magnitudeSize or scale
solar mass · O-type · B-type · F-type · fitting
Central body heat level
- energy balanceIntake versus expenditure ratio
- thermal equilibriumEqual temperature throughout system
- stabilityResistance to displacement
- steady stateUnchanging system condition
self-regulation · pressure gradient · density · opacity · energy generation
Exit from main road
- star formationDense cloud becomes sun
- protostarPre-fusion celestial body
- billion yearsThousand million revolutions around sun
- fuel consumptionRate of burning energy
luminosity
Intrinsic brightness of source
core temperature
Central body heat level
- energy balanceIntake versus expenditure ratio
- thermal equilibriumEqual temperature throughout system
- stabilityResistance to displacement
steady state · self-regulation · pressure gradient · density · opacity · energy generation
turnoff
Exit from main road
- star formationDense cloud becomes sun
- protostarPre-fusion celestial body
- billion yearsThousand million revolutions around sun
- starsstars, Sirius, Polaris, sol, sun
- astrophysicsblack hole, neutron star, supernova, black holes, neutron stars
- stellar propertiesluminosity, surface temperature, magnitude, brightness, stellar wind
- stellar phenomenasupernova, nova, star formation, nuclear fusion, nucleosynthesis
- astronomystars, moon, sun, planet, planets
- space objectsgalaxy, star cluster, nebula, planet, quasar
main sequencered giant
Aged star with cooled, expanded envelope
white dwarf · supergiant · neutron star · black hole · red supergiant