What is the HR diagram named after?

One of the most useful and powerful plots in astrophysics is the Hertzsprung-Russell diagram (hereafter called the H-R diagram). It originated in 1911 when the Danish astronomer, Ejnar Hertzsprung, plotted the absolute magnitude of stars against their colour (hence effective temperature).

Who the scientists the H-R diagram is named after where are they from?

You can see an example of a Hertzsprung-Russell diagram to the right. This diagram is based on measurements from 23,000 stars in our Milky Way galaxy. The Hertzsprung-Russell diagram is named after its creators, astronomers Ejnar Hertzsprung and Henry Norris Russell.

What does HR stand for in H-R diagram?

The Hertzsprung–Russell diagram, abbreviated as H–R diagram, HR diagram or HRD, is a scatter plot of stars showing the relationship between the stars’ absolute magnitudes or luminosities versus their stellar classifications or effective temperatures.

What is another name for the H-R diagram?

Hertzsprung–Russell diagrams are also referred to by the abbreviation H–R diagram or HRD. The diagram was created circa 1910 by Ejnar Hertzsprung and Henry Norris Russell and represents a major step towards an understanding of stellar evolution or “the lives of stars”.

Why was the H-R diagram created?

The chart was created by Ejnar Hertzsprung and Henry Norris Russell in about 1910. It is a very useful graph because it can be used to chart the life cycle of a star. We plot stars’ surface temperatures in degrees Kelvin on the x-axis (horizontal axis).

Where is Betelgeuse on the HR diagram?

Betelgeuse in the constellation Orion — X-axis: 3000K, Y-axis 10 ⁵ M.

What is an HR diagram quizlet?

WHAT IS A HERTZSPRUNG-RUSSELL DIAGRAM? A diagram that shows the relationship or differences between SURFACE TEMPERATURE and LUMINOSITY of STARS.

What are the axis of an HR diagram quizlet?

Terms in this set (22)



The horizontal (x) axis on a Hertzsprung-Russell (HR) diagram represents (mark all that apply). The vertical (y) axis on a Hertzsprung-Russell (HR) diagram represents (mark all that apply). distance. apparent brightness.

What does an HR diagram relate a star’s temperature to?

Developed independently in the early 1900s by Ejnar Hertzsprung and Henry Norris Russell, it plots the temperature of stars against their luminosity (the theoretical HR diagram), or the colour of stars (or spectral type) against their absolute magnitude (the observational HR diagram, also known as a colour-magnitude …

What is the horizontal axis of the HR diagram?

The horizontal axis represents the star’s surface temperature (not the star’s core temperature – we cannot see into the core of a star, only its surface)! Usually this is labeled using the Kelvin temperature scale. But notice : In most graphs and diagrams, zero (or the smaller numbers) exist to the left on the diagram.

How is the H-R diagram different from most diagrams?

Contrary to most graphs, which typically display the temperature scale from the least to greatest values, the scaled temperatures on the HR diagram decrease from left to right. The y-axis denotes the absolute magnitude, or luminosity of stars, ranging from the dimmest to the brightest in solar units.

How do you draw an H-R diagram?

Video quote: But we need to make sure that our band of main sequence stars is in the right place a good way to do that is to remember some of the properties of our Sun.

What are the four sections in the H-R diagram?

This diagram illustrates the four main main regions where we find stars on an HR diagram: the main sequence, white dwarfs, giants, and supergiants (though in this example there is not a very clear boundary between giants and supergiants).

What are the 4 main groups of stars?

So, let’s take a look at all the different types of stars that have been discovered so far.

• Protostar. …
• T Tauri Stars. …
• Main Sequence Stars. …
• Red Giant Stars. …
• White Dwarf Stars. …
• Red Dwarf Stars. …
• Neutron Stars. …
• Supergiant Stars.

What are the three main groups found an 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.

Why is the HR diagram important?

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.

What comes after main sequence star?

After the hydrogen fuel at the core has been consumed, the star evolves away from the main sequence on the HR diagram, into a supergiant, red giant, or directly to a white dwarf.

What are the 6 stages of a star?

Formation of Stars Like the Sun

• STAGE 1: AN INTERSTELLAR CLOUD.
• STAGE 2: A COLLAPSING CLOUD FRAGMENT.
• STAGE 3: FRAGMENTATION CEASES.
• STAGE 4: A PROTOSTAR.
• STAGE 5: PROTOSTELLAR EVOLUTION.
• STAGE 6: A NEWBORN STAR.
• STAGE 7: THE MAIN SEQUENCE AT LAST.

What are the 5 stages of a star?

The formation and life cycle of stars

• A nebula. A star forms from massive clouds of dust and gas in space, also known as a nebula. …
• Protostar. As the mass falls together it gets hot. …
• Main sequence star. …
• Red giant star. …
• White dwarf. …
• Supernova. …
• Neutron star or black hole.

What comes after a protostar?

For our Sun, and stars of the same mass, the protostar phase would have ended after approximately 100,000 years. After this, the protostar stops growing and the disk of material surrounding it is destroyed by radiation. If the protostar was unsuccessful in acquiring enough mass, a brown dwarf will come into shape.

What happens after a protostar is formed?

A protostar becomes a main sequence star when its core temperature exceeds 10 million K. This is the temperature needed for hydrogen fusion to operate efficiently. The length of time all of this takes depends on the mass of the star. The more massive the star, the faster everything happens.

What comes after the nebula stage?

A smaller star, like the Sun, will gradually cool down and stop glowing. During these changes it will go through the planetary nebula phase, and white dwarf phase. After many thousands of millions of years it will stop glowing and become a black dwarf. A massive star experiences a much more energetic and violent end.

What is the second stage of a stars life cycle?

STAGE 2: A Protostar Is a Baby Star



A protostar is a very young star that is still in the process of gathering mass from its parent molecular cloud. The protostar phase is the earliest one in the process of stellar evolution.

What are the 7 stages of star formation?

Seven Main Stages of a Star

• Giant Gas Cloud. A star originates from a large cloud of gas. …
• Protostar. When the gas particles in the molecular cloud run into each other, heat energy is produced. …
• T-Tauri Phase. …
• Main Sequence. …
• Red Giant. …
• The Fusion of Heavier Elements. …
• Supernovae and Planetary Nebulae.

What are the 3 end stages of stars?

Three and stages of stars are white dwarf, neutron star and a black hole.