There are two factors in "apparent magnitude", or, how bright a star appears to be. These are absolute magnitude, how bright the star really is, and distance. Very bright stars will seem to be bright even when they are a long distance away.
On the other hand, the closest star to the Sun is the red dwarf Proxima Centauri, which is invisibly dim, EVEN THOUGH it is the nearest star. It's a tiny red dwarf.
The apparent brightness depends mainly on:
A star's luminosity is basically how much light it gives out per second.
How bright the star appears to us also depends on the star's distance from Earth.
So, a particular star can appear dimmer than another star even though it really has a greater luminosity.
The stellar classification [See link] in order of temperature. Luminosity (L) is based on our Sun. Our Sun is classed as yellow and has a luminosity of 1.
* Blue > 30,000 Kelvin. > 30,000 L
* Blue to blue white 10,000 -> 30,000 Kelvin. 25 -> 30,000 L
* White 7,500 -> 10,000 Kelvin. 5 -> 25 L
* Yellowish White 6,000 -> 7,500 Kelvin. 1.5 -> 5 L
* Yellow 5,200 -> 6,000 Kelvin. 0.6 -> 1.5 L
* Orange 3,700 -> 5,200 Kelvin. 0.08 -> 0.6 L * Red 1,000 < 3,700 Kelvin. <0.08 L * Brown < 1,000 Kelvin
* Black 0 Kelvin See link [Kelvin] for conversion ratios.
Its temperature and it's size. You can have two stars of the same luminosity, but one is small and hot and the other is huge and cool.
For apparent brightness - distance from the observer will also have an effect.
Here are some factors that contribute to the brightness of a star:
~ Apparent magnitude
~ Distance from Earth
~ Size
~ Surface temperature
I hope this helps!!
The apparent brightness of a star is how the star appears to us on Earth. The absolute brightness of a star is what the apparent brightness of a star would look like if it were 10 parsecs away from Earth. These are more formally called the Absolute Visual Magnitude and Apparent Visual Magnitude of a star.
At a higher temperature, the star will shine more brightly for each square meter of surface. The total luminosity per square meter is approximately proportional to the fourth power of its absolute temperature. This refers to the energy output, considering all types of electromagnetic waves, not just visible light.
The answer is complicated but the major factors that contribute to us seeing a star brighter or not are the distance to that star from Earth and the size and type of star it is.
The bigger the star's radius, the greater its surface area which emits the light. The bigger the temperature, the more luminous is the light the star is emitting.
Three factors that affect a star's brightness are the star's distance from earth, its age and its luminosity. The farther the star is from earth, the less bright it appears. As a star increases in age, its brightness also increases. Its brightness also depends on its luminosity, which is the amount of energy the star emits per second.
A nova is a star that suddenly increases in brightness.
How old a star is.
Sirius.
Apparent magnitude.
distance from the sun and the age of the star
Composition and distance.
Three factors that affect a star's brightness are the star's distance from earth, its age and its luminosity. The farther the star is from earth, the less bright it appears. As a star increases in age, its brightness also increases. Its brightness also depends on its luminosity, which is the amount of energy the star emits per second.
How dense it is, and how far away it is.
Two factors that affect a star's apparent brightness are: 1.) The distance between the Earth and the star 2.) The absolute magnitude (the actual brightness) of the star Hope that helps :P
Distance from Earth, size of star, and temperature of star.
Distance from Earth, size of star, and temperature of star.
Distance and intervenng or close celestial bodies
Distance and intervenng or close celestial bodies
Distance and intervenng or close celestial bodies
Age of the star, size, and temperature. The answer is in another post that I saw.
Distance and intervenng or close celestial bodies