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The Greeks had a system of classifying stars according tot heir brightness. The main Greek astronomer to use magnitudes was Ptolemy.
But the modern system of magnitudes was devised by Norman Pogson. A 1st magnitude star is defined as being 100 times brighter than a 6th magnitude star. A difference of one magnitude is equivalent to 2.512 times brighter or fainter.
What else can I help you with?
What are the two ways stars are classified?
Stars are classified based on their spectral characteristics, which categorizes them into spectral types (O, B, A, F, G, K, M) based on the temperature of their surface. They are also classified based on their luminosity, which categorizes them into different classes (I, II, III, IV, V) based on their brightness compared to the Sun.
Do stars have the same brightness and sizes?
No. Stars vary greatly in size and brightness.
Which two groups of stars can have similar brightness?
Variable stars and main sequence stars can have similar brightness. Variable stars, like Cepheid variables, can fluctuate in brightness over time, while main sequence stars maintain a relatively stable brightness due to their fusion processes.
Who made the first catalog of stars?
The first catalog of stars is credited to the Greek astronomer Hipparchus, who compiled his observations in the 2nd century BCE. Hipparchus cataloged around 850 stars and classified them based on their brightness.
What is a stars brightness known as?
A star's brightness is known as its magnitude. Stars with lower magnitude numbers are brighter than stars with a higher magnitude number.
What are the ways stars are classified?
Two ways are by temperature and brightness
What two characteristics are stars classified by?
They are classified by the amount of Light they give off, and their temperature.
How are stars classifieds?
Stars are classified by their color, temperatures, sizes, and brightness, it could also be by composition and radiation.Scientists classify stars by color, luminosity, and temperature.
What are the two ways stars are classified?
Stars are classified based on their spectral characteristics, which categorizes them into spectral types (O, B, A, F, G, K, M) based on the temperature of their surface. They are also classified based on their luminosity, which categorizes them into different classes (I, II, III, IV, V) based on their brightness compared to the Sun.
Do stars have the same brightness and sizes?
No. Stars vary greatly in size and brightness.
How are stars ranked according to temperature and brightness?
To do so, astronomers calculate the brightness of stars as they would appear if it were 32.6 light-years, or 10 parsecs from Earth. Another measure of brightness is luminosity, which is the power of a star - the amount of energy (light) that a star emits from its surface.
What are the two ways stars are classified according to this chart?
spectrum and temperature
Which two groups of stars can have similar brightness?
Variable stars and main sequence stars can have similar brightness. Variable stars, like Cepheid variables, can fluctuate in brightness over time, while main sequence stars maintain a relatively stable brightness due to their fusion processes.
Who made the first catalog of stars?
The first catalog of stars is credited to the Greek astronomer Hipparchus, who compiled his observations in the 2nd century BCE. Hipparchus cataloged around 850 stars and classified them based on their brightness.
What is a stars brightness known as?
A star's brightness is known as its magnitude. Stars with lower magnitude numbers are brighter than stars with a higher magnitude number.
What are the four ways stars can be classified?
I don't know if this is THE four ways, but here are four possible ways:Temperature/Color (amounts to the same thing)SizePopulation ("metallicity" is essentially a different description of pretty much the same thing)Mass
Temperature and brightness of stars are indicated by what?
Temperature of stars is indicated by their color, with blue stars being hotter than red stars. Brightness of stars is indicated by their luminosity, which is how much light a star emits.
