Isadore Epstein facts for kids

Isadore Epstein was an important astronomer. He was born in Tallinn, Estonia, on October 23, 1919. He passed away in New York City on September 17, 1995. Dr. Epstein taught astronomy at Columbia University for 37 years. He earned his Ph.D. from Princeton University. He started teaching at Columbia in 1950. Over the years, he became a full professor in 1971. He was a professor emeritus starting in 1987.

Studying the Sun

Isadore Epstein's early work focused on understanding the Sun. He helped create computer models of the Sun. These models helped scientists learn how the Sun works. He worked with Martin Schwarzschild at Princeton on these ideas.

Epstein was the first to understand how important "opacity" is. Opacity means how much matter blocks light and energy. For the Sun, it means how much its material resists the flow of solar radiation. His ideas helped create the first Sun models that correctly showed how much energy the Sun produces.

Finding Observatory Sites

Dr. Epstein was a leader in finding the best places for observatories. Observatories are special buildings with large telescopes. They need very clear and stable air to see the stars well. He looked for sites in the Southern Hemisphere.

During the 1960s, he studied places in Australia, South Africa, Chile, and Argentina. He checked how clear the sky was and how easy it was to reach these places. Major observatories were built at all the sites he suggested.

Key Observatories He Helped Establish

• Leoncito Observatory: Epstein was very involved with setting up the Leoncito observatory in Argentina. A long-term study of stellar motions (how stars move) began there. Argentina's national observatory later moved to this site.
• Chilean Observatories: The famous La Silla and Cerro Tololo observatories in Chile were built based on Epstein's research.
• Mauna Kea: His methods for choosing observatory sites were also used for Mauna Kea in Hawaii. Mauna Kea is now one of the world's most important observatory locations.

Honor

An asteroid was named after Isadore Epstein. This asteroid, called 2928 Epstein, was discovered at the La Silla Observatory. This observatory is one of the places he helped to find.