In the early 20th century, Danish astrophysicist Ejnar Hertzsprung and American astrophysicist Henry Norris Russell independently developed a graph now known as the Hertzsprung-Russell (H-R) diagram, which plots absolute brightness against spectral type. In this diagram, the brightest stars lie near the top of the diagram and the hottest stars lie to the left. On the H-R diagram, most of the stars, including the Sun, fall along a diagonal line that goes from the upper left to the lower right of the diagram. This line called the main sequence.The great majority of stars neighboring the Sun fall on the lower part of the H-R diagram's main sequence, and relatively few lie on the portion of the main sequence above the Sun. This means that most of the Sun's neighboring stars are both cooler and fainter (in absolute magnitude) than the Sun. A smaller population of brighter but cooler stars known as supergiants occupies the uppermost region of the diagram. Some stars, which are difficult to discover because they are so intrinsically faint, lie near the bottom of the H-R diagram. These faint stars are called white dwarfs.
The concept of stellar evolution was significantly advanced by the work of astrophysicists such as Sir William Herschel in the 18th century, but it was further developed in the 20th century by scientists like Subrahmanyan Chandrasekhar, who studied the life cycles of stars and the processes leading to phenomena like supernovae and black holes. The Hertzsprung-Russell diagram, created by Ejnar Hertzsprung and Henry Norris Russell, also played a crucial role in understanding how stars evolve over time based on their luminosity and temperature. Overall, the discovery of stellar evolution is attributed to the contributions of many scientists over time.
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".
Henry Horn, who played the character Apollo in the film "Apollo 13," was born on June 10, 1950.
The first American man in space was Alan Shepard. He made history on May 5, 1961, when he piloted the Freedom 7 spacecraft during the Mercury-Redstone 3 mission. Shepard's flight lasted only 15 minutes, but it paved the way for future American space exploration.
Henry Norris Russell died on 1957-02-18.
Henry Norris Russell was born on 1877-10-25.
The Hertzsprung-Russell diagram was created - as the name suggests - by Ejnar Hertzsprung and Henry Norris Russell in 1910
Henry Norris Russell died on February 18, 1957 in Princeton, New Jersey from a heart attack. He was 79 years old at the time of his death. Russell was a renowned American astronomer known for his work in stellar classification and the Hertzsprung-Russell diagram.
Henry Norris Russell has written: 'On the relations between period, luminosity, and spectrum among Cepheids' -- subject(s): Magnitudes, Spectra, Stars, Variable stars 'The determination of the elements of eclipsing binaries' -- subject(s): Eclipsing binaries, Orbits 'Some problems of sidereal astronomy' -- subject(s): Accessible book, Astronomy 'Position of the moon determined photographically' -- subject(s): Observations 'Is there argon in the corona?' -- subject(s): Argon, Corona, Solar Spectrum 'Molecules in the sun and stars' -- subject(s): Molecules, Solar Spectrum, Spectra, Stars 'Astronomy' -- subject(s): Astronomy 'The solar system and its origin' 'The composition of the stars' -- subject(s): Constitution, Stars 'On the spectra of doubly and trebly ionized titanium' -- subject(s): Spectrum analysis, Titanium
Ejnar Hertzsprung and Henry Norris Russell,working independently, realized the relationship between a star's temperature and its brightness.Together, in 1910, they formed what is now known as the Hertzsprung--Russell diagram or HR Diagram.It's a scatter graph showing the relationship between a star's absolute magnitudes, their spectral types and temperatures.
Henry Handley Norris was born in 1771.
Henry Handley Norris died in 1850.
The diagram was created by Ejnar Hertzsprung and Henry Norris Russell aound 1910.
Henry Norris - businessman - was born on 1865-07-23.
Henry Norris - businessman - died on 1934-07-30.
Henry Norris has written: 'Baddelsey Clinton' -- subject(s): Church history