Cepheids are a type of very luminous variable stars. There is a strong direct relationship between a Cepheid's luminosity and pulsation period. This makes Cepheids important standard candles for the galactic and extragalactic distance scales.
Cepheid variables are divided into several subclasses which exhibit clearly different masses, ages, and evolutionary histories:
The first cepheid known was Delta Cephei in the constellation Cepheus, found by John Goodricke in 1784. Delta Cephei is of great importance because its distance is extremely well known, thanks in part to it being in a star cluster, and the precise Hubble Space Telescope/Hipparcos parallaxes.
Classical Cepheids (also known as Population I Cepheids, Type I Cepheids, or Delta Cephei variables) pulsate with very regular periods of the order of days to months. Classical Cepheids are population I young variable stars which are 4–20 times more massive than the Sun, and up to 100,000 times more luminous. Cepheids are yellow supergiants of spectral class F6 – K2. When they pulsate, their radii change by ~25%. For the longer-period I Carinae this means millions of kilometers for a pulsation cycle.
Type II Cepheids (also termed Population II Cepheids) are population II variable stars which pulsate with periods between 1 and 50 days. Type II Cepheids are typically metal-poor, old (~10 giga years), low mass objects (~half the mass of the Sun). Type II Cepheids are divided into several subgroups by period.
Type II Cepheids are used to fix the distance to the galactic center of the Milky Way, globular clusters, and galaxies.
A group of pulsating stars on the instability strip have periods of less than 2 days, similar to RR Lyrae variables but with higher luminosities. Anomalous Cepheid variables have masses higher than type II Cepheids, RR Lyrae variables, and our sun. It is unclear whether they are young stars on a "turned-back" horizontal branch, blue stragglers formed through mass transfer in binary systems, or a mix of both.
A small proportion of Cepheid variables have been observed to pulsate in two modes at the same time, usually the fundamental and first overtone, occasionally the second overtone. A very small number pulsate in three modes, or an unusual combination of modes including higher overtones.
GloFish
Glofish are fish which glow in the dark. They glow because scientists changed their DNA to make them fluorescent. The seahorse and the zebra fish are two types of fish that have been used to make GloFish.
Lazarus Saturday
Lazarus Saturday is the day before Palm Sunday in the Orthodox Church. It celebrates the raising of Lazarus from the dead by Jesus (Gospel of John chapter 11). It is the start of Holy Week.
Joe Weider
Josef Edwin "Joe" Weider (November 29, 1919 – March 23, 2013) was a Canadian-American bodybuilder, trainer, businessman, and television personality. He was the founder of Mr. Olympia.
Weider was born on November 29, 1919 in Montreal, Quebec, Canada to a Polish-Jewish family. He was raised in Los Angeles, California. His brother was Ben Weider. Weider was married to Betty Brosmer from 1961 until his death in 2013. They had no children. Weider died on March 23, 2013 from heart failure in Los Angeles, California, aged 93.
George Pullman
George Mortimer Pullman (March 3, 1831 – October 19, 1897) was an American engineer and businessman. At the time of his death, he bequeathed 1.2 million dollars for a free school of manual training in the town of Pullman.
Pullman invented the Pullman sleeping car. He founded a company town, Pullman. He did all of his business in Chicago. He was supported by President Grover Cleveland during the Pullman Strike in Chicago.
Pullman was born on March 3, 1831 in Brocton, New York. He was raised in Albion, New York. Pullman was married to Hattie Amelia Sanger from 1867 until his death in 1897. They had four children. Pullman died on October 19, 1897 in Chicago, Illinois from a heart attack, aged 66. He was buried at Graceland Cemetery.
Compound fruit
The term compound fruit is sometimes used when it is not clear which of several fruit types a fruit belongs to. A compound fruit is "composed of two or more similar parts".
A compound fruit may be:
Grapes grow in clusters, but are not compound fruits. Each grape is grown from one ovary in one flower, and they are not attached to one another.
Boeing 80
The Boeing 80, sometimes called the Boeing Model 80 or just the Model 80, was an American airliner. It was a biplane with three engines. The Boeing 80 was built by the Boeing Airplane Company. It could carry mail and passengers.
Boeing Air Transport was started on February 17, 1927 by William Boeing. On July 1, 1927, planes from Boeing Air Transport started flying mail from San Francisco to Chicago. At first, the Boeing Model 40A was used for this.
Boeing decided to make a plane to carry passengers. In 1928 it designed the Model 80. The Boeing 80 could carry 12 people. The pilots sat in a cockpit in front of the passengers.
The first Boeing 80 took off on July 27, 1928. Three more Boeing 80s were made before Boeing started to make the Boeing 80A. The Boeing 80A was longer and it could carry 18 people. It also had better engines. It first took off on July 18, 1929.
The Boeing 80 first flew for Boeing Air Transport on September 20, 1928. It soon turned out to be successful. The Boeing 80A started being used in September 1929.
In May 1930, Boeing Air Transport hired eight female flight attendants. They first flew on May 15. The Boeing 80 and 80A were used until the Boeing 247 replaced them in 1934.
One Boeing 80A was found in a dump at Anchorage Airport in 1960. It was fixed up and it is now in the Museum of Flight in Seattle.
Boeing Monomail
The Boeing Model 200 Monomail was an American mail plane. It was built in the 1930s by Boeing. It flew for the first time on 6 May 1930.
The Boeing Monomail was a monoplane instead of a biplane. The wing was strong and did not need bracing. Its wheels could be ed. Only one plane was made for the US Army to look at. The plane eventually began to fly main from San Francisco to Chicago.
Another version was made, the Model 221. It was made longer by 8 inches. This meant it could carry passengers, but less cargo. This version first flew on 18 August 1930.
There were no good engines for the Boeing Monomail to use. By the time good engines could be used, new planes had been made which were better than the Monomail. One of these was the Boeing 247.
Giora Feidman
Giora Feidman (born March 26, 1936) is an Israeli clarinetist. He plays klezmer music.
Giora Feidman was born in Buenos Aires, Argentina. His Bessarabian Jewish parents immigrated there to escape persecution. Feidman's family are klezmer musicians. His father, grandfather and great-grandfather made music for weddings, Bar Mitzvahs, and holiday celebrations in the shtetls (villages) of Eastern Europe. Feidman married Ora Bat-Chaim in 1975. She was his personal manager.
Feidman started his career in Buenos Aires, where he was a member of the Teatro Colón Symphony Orchestra. Two years later he immigrated to Israel. He became the youngest clarinetist ever to play with the Israel Philharmonic Orchestra. He was a member of the orchestra for over 20 years. In the early 1970s he started a solo career. He has performed with the Berliner Symphoniker, the Kronos Quartet, the Polish Chamber Philarmonic, the Munich Chamber Philarmonic Orchestra, and the Munich Radio Orchestra.
Feidman started the "Clarinet and Klezmer in the Galilee" seminar and master class program, which takes place every year in Safed, Israel.
Louis Jourdan
Louis Jourdan (Louis Robert Gendre, June 19, 1921 – February 14, 2015) was a French retired actor. He appeared in "The Paradine Case" (1947), "Gigi" (1958), "The Best of Everything" (1959) and "Octopussy" (1983). His final movie before his retirement was "The Year Of The Comet" in 1992.