# What is the formula for effective temperature?

## What is the formula for effective temperature?

The effective temperature of a star is the temperature of a black body with the same luminosity per surface area (FBol) as the star and is defined according to the Stefan–Boltzmann law FBol = σTeff4. Notice that the total (bolometric) luminosity of a star is then L = 4πR2σTeff4, where R is the stellar radius.

How is luminosity related to temperature?

” The Luminosity of a star is proportional to its Effective Temperature to the 4th power and its Radius squared.” Example 1: Two stars are the same size, (RA=RB), but star A is 2x hotter than star B (TA=2TB): Therefore: Star A is 24 or 16x brighter than Star B.

### What do you mean by effective temperature of a star?

The effective temperature of a star is the temperature of a Black Body of the same size as the star and that would radiate the same total amount of electromagnetic power as emitted by the star.

Is effective temperature the same as surface temperature?

The surface temperature, calculated by assuming a perfect blackbody radiating the same amount of energy per unit area as the star, is known as the effective temperature of the star.

## What is effective temperature scale?

The standard environment chosen is the Effective Temperature (ET) Scale, used by the American Society of Heating, Refrigerating and Air-Conditioning Engineers; namely, as the temperature of an isothermal enclosure at sea level with 50% rh and still air (0.1-0.15 m/s) in which a clothed (0.6 clo) sedentary subject would …

How is luminosity calculated?

How is luminosity calculated? In order to calculate luminosity, the mathematical constant “pi” (3.14) is used. The distance of the object from Earth in square meters is multiplied by the object’s brightness in watts per square meters. That is then multiplied by 3.14 and then again by 4 to calculate luminosity.

### What is the relationship between temperature and brightness of the main sequence?

Main sequence is when a star is burning hydrogen in its core. The luminosity and temperature of a main-sequence star are set by its mass. More massive means brighter and hotter.

How do you use luminosity formula?

## What is the luminosity distance formula?

More generally, the luminosity, apparent flux, and distance are related by the equation f = L/4`pi’d2. If we measure a star’s parallax and its apparent brightness, we can determine its luminosity, which is an important intrinsic property.

What is the importance of effective temperature?

The temperature at which motionless saturated air would induce, in a sedentary worker wearing ordinary indoor clothing, the same sensation of comfort as that induced by the actual conditions of temperature, humidity, and air movement.

### What is effective temperature in air conditioning?

The effective temperature is the temperature of the saturated environment at which motionless saturated air would induce same level of comfort as experienced in a normal environment in a sedentary worker wearing ordinary indoor clothing.

What is the luminosity of a star formula?

If they know the star’s brightness and the distance to the star, they can calculate the star’s luminosity: [luminosity = brightness x 12.57 x (distance)2]. Luminosity is also related to a star’s size. The larger a star is, the more energy it puts out and the more luminous it is.

## Which statement best describes the general relationship between the temperature and luminosity?

Q. Which statement describes the general relationship between the temperature and the luminosity of main sequence stars? As temperature decreases, luminosity remains the same.

How do the size and temperature of a star affect its luminosity?

As the size of a star increases, luminosity increases. If you think about it, a larger star has more surface area. That increased surface area allows more light and energy to be given off. Temperature also affects a star’s luminosity.

### How is luminosity measured?

In SI units, luminosity is measured in joules per second, or watts. In astronomy, values for luminosity are often given in the terms of the luminosity of the Sun, L⊙.

How do you calculate luminosity from flux and distance?

Knowing the flux (f) and distance to the object (r), we can calculate its luminosity: L=4πr2f. Therefore, flux and luminosity are intrinsic properties of the object, while brightness depends on our detecting tools (hardware and software).

## What factors affect effective temperature?

Which are the factors governing effective temperature? The degree of warmth or cold felt by a human body depends mainly on following three factors: (a) Dry bulb temperature (b) Relative humidity (c) Air velocity. Effective temperature is used to evaluate the combined effect of all these factors.

What is the difference between DBT and WBT called?

The difference between the DBT and WBT is called as wet bulb depression.