What is timescale in astronomy?

In astronomy and physics: Dynamical time scale, in stellar physics, the time in which changes in one part of a body can be communicated to the rest of that body, or in celestial mechanics, a realization of a time-like argument based on a dynamical theory.

What is Kelvin Helmholtz timescale?

In astrophysics, the thermal time scale or Kelvin-Helmholtz time scale is the approximate time it takes for a star to radiate away its total kinetic energy content at its current luminosity rate.

What does Stellar mean in physics?

Stellar observations reveal the properties of stars, their environment and even the presence of planets. Common birth place and age. Theoretical models (such as depicted in the image on the left) predict physical conditions and dynamics in depths and on scales that cannot be reached by observations.

How do you calculate nuclear time scale?

The nuclear time scale is the time in which a star radiates away all the energy that can be released by nuclear reactions. This time can be estimated by calculating the time taken by all available hydrogen burning.

What are the different timescales?

The Four Eras of the Geologic Time Scale

  • Precambrian Time: 4.6 billion to 542 Million Years Ago. John Cancalosi / Getty Images.
  • Paleozoic Era: 542 Million to 250 Million Years Ago. Jose A.
  • Mesozoic Era: 250 Million to 65 Million Years Ago. Science Library / Getty Images.
  • Cenozoic Era: 65 Million Years Ago to the Present.

Which part of stellar evolution does the Kelvin Helmholtz time describe?

The Kelvin–Helmholtz timescale describes the duration of the contraction phase of a star when it (temporarily) runs out of nuclear fusion.

What is gravitational contraction?

Gravitational collapse is the contraction of an astronomical object due to the influence of its own gravity, which tends to draw matter inward toward the centre of gravity. Gravitational collapse is a fundamental mechanism for structure formation in the universe.

What does stellar performance mean?

extremely good
a stellar performance, achievement, piece of work etc is extremely good. Synonyms and related words. Words used to describe performers or performances.

What is stellar energy?

Definition of stellar energy 1 : the internal energy of a star. 2 : the energy radiated by a star. 3 : the energy of the stars.

What is Nuclear time?

In astrophysics, the nuclear timescale is an estimate of the lifetime of a star based solely on its rate of fuel consumption.

How do you calculate lifetime of a star?

The more mass a star has, the lower its life expectancy. The formula for the calculation is: lifespan of the star = lifespan of the sun * (star mass / solar mass) -2.5. The lifespan of the sun is estimated as 10 billion years.

What are the 4 major divisions of the geologic time scale?

The geologic time scale is divided into (from longest to shortest): eons, eras, periods, epochs and ages.