Radio’s Guide to the Universe

StarDate host Billy Henry

StarDate debuted in 1978, making it the longest-running national radio science feature in the country. It airs on more than 300 radio stations. It has been hosted by Billy Henry since July 2019.

StarDate tells listeners what to look for in the night sky, and explains the science, history, and skylore behind these objects. It also keeps listeners up to date on the latest research findings and space missions. And it offers tidbits on astronomy in the arts and popular culture, providing ways for people with diverse interests to keep up with the universe.

StarDate is a production of The University of Texas McDonald Observatory, which also produces the bi-monthly StarDate magazine.

The Voice of StarDate

Billy Henry, a voice talent, musician, composer, and college lecturer in Austin is the third narrator of the StarDate radio program. Read more »

The Music of StarDate

The StarDate background music was written by Bill Harwell and Patterson Barrett specifically for StarDate.

More Than 40 Years and Counting!

StarDate is radio’s longest-running nationally aired science program. It began in 1977 as a daily telephone message service by McDonald Observatory. It was picked up by Austin radio station KLBJ-FM, and aired as “Have You Seen the Stars Tonight?” beginning in June 1977. With a grant from the National Science Foundation, the program became “Star Date,” and began airing nationally, seven days per week, on October 1, 1978. It quickly reached more than 1,000 stations across the country. Read more »

Today’s Episode

Kochab

The Little Dipper is famous for the star at the tip of its handle: Polaris, the North Star. Earth’s axis points in that direction, so all the other stars in the night sky appear to circle around it.The second-brightest star in the dipper is Kochab, at the lip of the bowl. It isn’t nearly as famous as Polaris, but it’s almost as bright.Kochab is a giant — more than 40 times the Sun’s diameter, and almost 400 times its brightness. It’s so big because it’s nearing the end of its life. The nuclear reactions deep inside the star push on the surrounding layers of gas, making them puff outward.Just when a star enters the giant phase of life depends on its mass. Heavier stars age much faster, so they “burn out” more quickly. And Kochab is more massive than the Sun.But just how massive has been the subject of debate. Studies using different techniques have yielded estimates of about 1.3 to 2.5 times the Sun’s mass. If Kochab had a companion star, it would be easy for scientists to measure the masses of both stars. For solitary stars like Kochab, though, astronomers rely on models of how stars behave. Today, the models seem to indicate a mass of about 2.2 times the Sun’s. But that isn’t completely settled. Until it is, we won’t know the complete story of Kochab.Kochab is moderately bright, and stands to the right of Polaris at nightfall. It rotates directly above the Pole Star in the wee hours of the morning.Script by Damond Benningfield
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Upcoming Topics

  • April 22-28: Taking a Trip

    A trip around the world would take a while, even in a passenger jet. But it’s the blink of an eye compared to the time it would take to go around a supergiant star.

  • April 15-21: A Cosmic “Dusting”

    Earth is headed through a ribbon of “comet dust” — debris that causes the Lyrid meteor shower. And some of that dust may have been found at the bottom of a river, and we’ll have details.

  • April 8-14: Disrupting Planets

    Many planets in other star systems are being torn apart — some by the radiation and winds from their stars, and others by giant collisions.

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