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.
” The Luminosity of a star is proportional to its Effective Temperature to the 4 th power and its Radius squared .” Example 1: Two stars are the same size, (R A =R B ), but star A is 2x hotter than star B (T A =2T B ): Therefore: Star A is 2 4 or 16x brighter than Star B.
Does the brightness of a star depend on its size and temperature?
A glance at the night sky above Earth shows that some stars are much brighter than others. However, the brightness of a star depends on its composition and how far it is from the planet . ... Astronomers also measure luminosity — the amount of energy (light) that a star emits from its surface.
How do the brightness and temperatures of the stars differ with size?
How do the brightness and temperatures of the stars differ with size? The larger star is brighter, but not necessarily hotter . The larger star is cooler, but not necessarily brighter. The smaller star is fainter and cooler.
What makes the brightness of the stars?
However, the brightness of a star depends on its composition and how far it is from the planet. Astronomers define star brightness in terms of apparent magnitude
Which factor affects the color of the star?
The surface temperature of a star determines the color of light it emits. Blue stars are hotter than yellow stars, which are hotter than red stars.
What star has the highest luminosity?
| Name Constellation Bolometric luminosity (Solar lum.) | Sun 1 | Alpha Centauri A Centaurus 1.519 | Sirius Canis Major 25.4 | Vega Lyra 40.12 |
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What is the color of the hottest star?
White stars are hotter than red and yellow. Blue stars are the hottest stars of all.
Are larger stars brighter?
The closer a star is to us, the brighter it will appear . ... Larger stars usually shine more brightly than smaller stars do. So, how bright a star appears in the night sky depends on its size and how far away from us it is.
What star is dimmer than the sun?
The diagram on the previous page shows a star’s luminosity relative to Earth’s Sun. So, stars alongside the 102 tick mark are 100 times brighter than the Sun, and stars alongside the 10–2 tick mark are 100 times dimmer than the Sun.
Why do star have colors?
The color of a star is linked to its surface temperature . The hotter the star, the shorter the wavelength of light it will emit. The hottest ones are blue or blue-white, which are shorter wavelengths of light. Cooler ones are red or red-brown, which are longer wavelengths.
Why do stars twinkle?
As light from a star races through our atmosphere, it bounces and bumps through the different layers, bending the light before you see it. Since the hot and cold layers of air keep moving, the bending of the light changes too , which causes the star’s appearance to wobble or twinkle.
Which star is the hottest?
The hottest one measures ~210,000 K; the hottest known star. The Wolf-Rayet star WR 102 is the hottest star known, at 210,000 K.
What star has a temperature of 20000 K?
O stars
Which two factors affect the brightness of a star?
However, the brightness of a star depends on its composition and how far it is from the planet . Astronomers define star brightness in terms of apparent magnitude
