Astronomia: Stellae Proprietates

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Questions and Answers

Qual es le proportionalitate del luminositate de un stella?

M^3.5 (correct)

M^4

M^2

Qual es le relation inter le massa de un stella e su vita?

t ∝ M^3.5

t ∝ M^4

t ∝ M^2.5

t ∝ M^-2.5 (correct)

Cual es le tipo spectral de Rigel?

B8Ia (correct)

M5V

A1V

G2V

Cual es le valor de luminositate de Alpha Centauri?

1.4 Signup and view all the answers

Qual es le relation inter le massa de un stella e su radie?

R ∝ M^0.5 Signup and view all the answers

Cual es le destination de formation de stellas?

Dense molecular clouds Signup and view all the answers

Qué charakteristica del curva de lumine de un sistema de binario eclisante revela information sur le dimensions del stellas?

La gradualitate del transitiones Signup and view all the answers

Qué es le causa de que solo few stellas massive sia formate in un cluster stellar?

Le selection effect, too faint to detect Signup and view all the answers

Qué es le methodo utilisate pro calcular le dimensions e altere proprietates de certe especie de stellas pulsante?

Le methodo de Cepheid variables Signup and view all the answers

Qué es le relation inter le dimensions del stellas in un sistema de binario eclisante?

Le dimensions del stellas es relate al sua massa Signup and view all the answers

Qué es le nomine del function que describe le distribution de massa stellar in un cluster stellar?

Initial Mass Function (IMF) Signup and view all the answers

Qué tipo de stellas es utili pro calcular le distances in le universe?

Cepheid variables Signup and view all the answers

Que valor de sin3 i es utilisate como estimate de massa statistical?

0.67 Signup and view all the answers

Per que motivo spectroscopic binaries descoperte ha inclinationes significantemente differente de 0°?

Perque il ha un efecto de selection Signup and view all the answers

Que es necessari para producir curvas de velocitate radial non sinusoidal?

Orbites eccentric Signup and view all the answers

Qual es le relation inter massa e luminositate per le major parte de stellas in le celo?

Massa-luminositate es directemente proportional Signup and view all the answers

Que caracteristica de stellas es proportional al sua massa?

Fuel supply Signup and view all the answers

Que evenimento marca le fine de vita de un stella?

Quando il es exhauste de Hydrogen Signup and view all the answers

Que parametro de un orbita es necessari para reproducer curvas de velocitate radial?

Eccentricitate de l'orbita Signup and view all the answers

Que es le nomine del effecto que influentia le discoveria de spectroscopic binaries?

Efecto de selection Signup and view all the answers

Study Notes

Stellar Properties and Mass-Luminosity Relation

The luminosity of a star is proportional to M^3.5, thus the lifetime of a star is t = M / M^3.5 ~ M^-2.5.
The mass-luminosity relation exists for the majority of stars in the sky.

Properties of Specific Stars

Rigel: B8Ia, mass = 10 Msun, luminosity = 44,000 Lsun, lifetime = 20 million years
Sirius: A1V, mass = 2.3 Msun, luminosity = 23 Lsun, lifetime = 1000 million years
Alpha Centauri: G2V, mass = 1.1 Msun, luminosity = 1.4 Lsun, lifetime = 7000 million years
Sun: G2V, mass = 1 Msun, luminosity = 1 Lsun, lifetime = 10,000 million years
Proxima Centauri: M5V, mass = 0.1 Msun, luminosity = 0.00006 Lsun, lifetime > 1,000,000 million years

Initial Mass Function

Stars are born in dense molecular clouds, leading to a range of stellar masses formed in a stellar cluster.
The initial mass function describes the number of stars of a given mass in mass intervals.
Few massive stars are formed, and many sub-solar mass stars are too faint to detect.

Eclipsing Binaries and Stellar Radii

Eclipses of eclipsing binaries do not occur instantaneously, but rather gradually, and the shape of the light curve is sensitive to the sizes of the stars.
The method of eclipsing binaries can be used to calculate the sizes and properties of certain kinds of pulsating stars, including Cepheid variables.

Pulsating Stars and Orbital Eccentricity

A statistical mass estimate can be found by choosing an appropriate average value for sin^3 i.
The integral average of sin^3 i (evaluated between 0° < i < 90°) is approximately 0.59.
Non-circular orbits produce non-sinusoidal velocity curves, which can be fitted with various values of eccentricity to accurately reproduce the velocity curves.

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Description

Quiz sobre le proprietates de stellae, includente luminositate, vita de stella, e datos de stellae como Rigel, Sirius, e Alpha Centauri