# What are the 4 groups on the H-R diagram?

## What are the 4 groups on the H-R diagram?

H-R Diagram Exercise By comparing the radii of different stars you will then find out the reason behind the names of the four categories of stars: white dwarfs, main-sequence stars, giants and supergiants.

### What are the 5 categories of stars on the H-R diagram?

The group called the main sequence extends in a rough diagonal from the upper left of the diagram (hot, bright stars) to the lower right (dim and cool). Large, bright, though cool, stars called giants and supergiants appear in the upper right, and the white dwarfs, dim, small, and hot, lie in the lower left.

#### What 4 things can the H-R diagram tell us about stars?

They can also reveal information about its temperature, motion through space, and its magnetic field strength. By plotting the stars on the H-R diagram according to their temperatures, spectral classes, and luminosity, astronomers can classify stars into their different types.

What is the Hertzsprung-Russell diagram and what is it used for?

The Hertzsprung-Russell diagram shows the relationship between a star’s temperature and its luminosity. It is also often called the H-R diagram or colour-magnitude diagram. The chart was created by Ejnar Hertzsprung and Henry Norris Russell in about 1910.

How do you plot an H-R diagram?

Plot the luminosity on the y-axis with brighter stars going toward the top. Since brighter stars have lower magnitudes, if you choose to plot magnitude on the y-axis, the values will decrease as you go up! That’s OK – just remember that the luminosity of the star is increasing. Plot temperature on the x-axis.

## What two things can the H-R diagram tell us about stars?

The position of each dot on the diagram tells us two things about each star: its luminosity (or absolute magnitude) and its temperature. The vertical axis represents the star’s luminosity or absolute magnitude.

### How does the H-R diagram show the life cycle of a star?

The Hertzsprung-Russell Diagram shows four main groupings of stars. These are the: Main sequence stars; these define a curved trend across the centre of the diagram which displays a relationship between mass and luminosity, such that stars with a high luminosity have a high effective temperature.

#### What are the 2 variables shown on the H-R diagram?

The Hertzsprung – Russell diagram shows the relationship between two factors: the absolute magnitude and. temperature of stars. With the help of these diagrams, we learn about the size, color and temperature of stars, about the arrangement of stars, about the influence of mass and temperature on the brightness of stars …

Why are the spectral classes listed as OBAFGKM?

What do the initials of “OBAFGKM” mean? A: It appears that when stars were first being classified in the 1890s, an astronomer at Harvard named Edward Pickering decided to sort the stars according to how much hydrogen they contained.

Why is the H-R diagram such a useful tool for astronomers?

HR diagrams are valuable because they reveal important information about the stars plotted on them. After constructing an HR diagram for a group of stars, an astronomer can make estimates of many important stellar properties including diameter, mass, age, and evolutionary state.

## How does H-R diagram help classify stars?

In an H-R diagram the luminosity or energy output of a star is plotted on the vertical axis. This can be expressed as a ratio of the star’s luminosity to that of the Sun; L*/Lsun. Astronomers also use the historical concept of magnitude as a measure of a star’s luminosity.