Hertzsprung–Russell diagramA 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 and their stellar classifications or effective temperatures. It is also sometimes called a color magnitude diagram.
1627 Ivar1627 Ivar (provisional designation 1929 SH) is an elongated stony asteroid and near-Earth object of the Amor group, approximately 15×6×6 km. It was discovered on 25 September 1929, by Danish astronomer Ejnar Hertzsprung at Leiden Southern Station, annex to the Johannesburg Observatory in South Africa. It was named after Ivar Hertzsprung, brother of the discoverer. 1627 Ivar was the first asteroid to be imaged by radar, in July 1985 by the Arecibo Observatory.
Henry Norris RussellHenry Norris Russell ForMemRS HFRSE FRAS (October 25, 1877 – February 18, 1957) was an American astronomer who, along with Ejnar Hertzsprung, developed the Hertzsprung–Russell diagram (1910). In 1923, working with Frederick Saunders, he developed Russell–Saunders coupling, which is also known as LS coupling.
1693 Hertzsprung1693 Hertzsprung (prov. designation: 1935 LA) is a dark and elongated background asteroid from the middle region of the asteroid belt, approximately 39 kilometers in diameter. It was discovered on 5 May 1935, by Dutch astronomer Hendrik van Gent at the Leiden Southern Station, annex to the Johannesburg Observatory in South Africa.
Karl SchwarzschildKarl Schwarzschild (German: [kaʁl ˈʃvaʁtsʃɪlt] ; 9 October 1873 – 11 May 1916) was a German physicist and astronomer. Schwarzschild provided the first exact solution to the Einstein field equations of general relativity, for the limited case of a single spherical non-rotating mass, which he accomplished in 1915, the same year that Einstein first introduced general relativity.
FrederiksbergFrederiksberg (Danish pronunciation:) is a part of the Capital Region of Denmark. It is an independent municipality, Frederiksberg Municipality, separate from Copenhagen Municipality, but both are a part of the region of Copenhagen. It occupies an area of less than 9 km and had a population of 103,192 in 2015. It is the most densely populated municipality in Denmark. Frederiksberg is an enclave surrounded by Copenhagen Municipality.
Göttingen ObservatoryGöttingen Observatory (Universitätssternwarte Göttingen (Göttingen University Observatory) or königliche Sternwarte Göttingen (Royal Observatory Göttingen)) is a German astronomical observatory located in Göttingen, Lower Saxony, Germany.
Absolute magnitudeMeasure of the luminosity of celestial objectsIn astronomy, absolute magnitude (M) is a measure of the luminosity of a celestial object on an inverse logarithmicastronomical magnitude scale; the more luminous (intrinsically bright) an object, the lower its magnitude number.
PhotochemistryPhotochemistry is the branch of chemistry concerned with the chemical effects of light. Generally, this term is used to describe a chemical reaction caused by absorption of ultraviolet (wavelength from 100 to 400 nm), visible (400–750 nm), or infrared radiation (750–2500 nm). A specialization of this branch at the nanoscale is nanophotochemistry.
Leipzig UniversityLeipzig University (German: Universität Leipzig), in Leipzig in Saxony, Germany, is one of the world's oldest universities and Germany's second-oldest university (by consecutive years of existence). The university was founded on 2 December 1409 by Frederick I, Elector of Saxony and his brother William II, Margrave of Meissen, and originally comprised the four scholastic faculties.
Stellar classificationIn astronomy, stellar classification is the classification of stars based on their spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting the rainbow of colors interspersed with spectral lines. Each line indicates a particular chemical element or molecule, with the line strength indicating the abundance of that element.
DanesDanes (Danish: danskere, pronounced), or Danish people, are an ethnic group and nationality native to Denmark and a modern nation identified with the country of Denmark. This connection may be ancestral, legal, historical, or cultural. HistoryEarly historyDenmark has been inhabited by various Germanic peoples since ancient times, including the Angles, Cimbri, Jutes, Herules, Teutones and others.
Cepheid variableA Cepheid variable () is a type of variable star that pulsates radially, varying in both diameter and temperature. It changes in brightness, with a well-defined stable period (typically 1–100 days) and amplitude. Cepheids are important cosmic benchmarks for scaling galactic and extragalactic distances; a strong direct relationship exists between a Cepheid variable's luminosity and its pulsation period.*As an Amazon Associate I earn from qualifying purchases.