How do you calculate luminosity?
Luminosity equation. Absolute and apparent magnitude. Calculating luminosity: an example….Luminosity equation
- σ is the Stefan Boltzmann constant, equal to 5.670367 * 10⁻⁸ ;
- A is the surface area of the body (equal to A = 4πR² for spherical objects);
- T is the temperature of the body, expressed in Kelvins.
How do you convert luminosity to Watts?
1 Solar Luminosity = 3.826×1033 ergs/s = 3.826×26 Joules/s = 3.826×26 Watts. 1 Jansky = 10-26 Joules s-1 m-2 = 10-26 Watts m.
Is luminosity A Watt?
Luminosity is frequently measured in watts (that is, joules per second). However, since stars are so very luminous, it is more convenient to measure their luminosities in units of the Sun’s luminosity, 3.9 x 1026 watts.
Do white dwarfs have a high luminosity of a low luminosity?
A typical white dwarf has a carbon and oxygen mass similar to the Sun, but is much smaller in size (similar to the Earth). It is much hotter (25,000 K), but because of its small size its luminosity is low.
What star has the highest luminosity?
List of stars more luminous than any closer star
| Name | Constellation | Bolometric luminosity (Solar lum.) |
|---|---|---|
| Sun | 1 | |
| Alpha Centauri A | Centaurus | 1.519 |
| Sirius | Canis Major | 25.4 |
| Vega | Lyra | 40.12 |
Is a white dwarf hotter than a red giant?
A white dwarf has a higher surface temperature than a red giant star.
What is the color of the hottest stars?
Blue stars
Why are red stars the coolest?
Red stars are cooler. They are red because they emit red light, which is lower in energy than blue light. Energy in turn, is proportional to temperature, which means that higher energy corresponds to higher temperatures.
Why are the hottest stars blue in color?
The colour that we see is usually an additive combination of the emissions from each wavelength. Hot stars appear blue because most energy is emitted in the bluer parts of the spectrum. There is little emission in the blue parts of the spectrum for cool stars – they appear red.
Which is the shiniest star?
Sirius, also known as the Dog Star or Sirius A, is the brightest star in Earth’s night sky. The name means “glowing” in Greek — a fitting description, as only a few planets, the full moon and the International Space Station outshine this star. Because Sirius is so bright, it was well-known to the ancients.