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StarDateYour guide to the universe Author: Billy Henry
StarDate, the longest-running national radio science feature in the U.S., tells listeners what to look for in the night sky. Language: en-us Genres: Astronomy, Education, Science Contact email: Get it Feed URL: Get it iTunes ID: Get it |
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Seeing Red
Tuesday, 3 February, 2026
In 1845, British astronomer J.R. Hind saw an amazing star in the constellation Lepus, the rabbit. He wrote that the star looked “like a drop of blood on a black field.” Officially, the star is called R Leporis. But it’s also known as Hind’s Crimson Star – a star that looks redder than almost any other star in the galaxy. R Leporis is a little heavier than the Sun. But it’s much later in life, which makes it a lot more interesting. It’s “fused” the original fuel in its core to make oxygen and carbon. Today, it’s producing energy in shells of hydrogen and helium around the core. Those changes have caused the star’s outer layers to puff up, so R Leporis is hundreds of times the Sun’s diameter. But those layers are unstable. They pulse in and out like a beating heart. Each “beat” lasts about 14 and a half months. During that cycle, the star’s brightness varies dramatically; at its peak, it’s hundreds of times brighter than at its faintest. As the star pulses, its temperature changes. At its largest, it’s a bit cooler, so it looks redder. And that color is amped up by the material in its outer layers. Carbon is pulled up from deep inside the star. It absorbs blue wavelengths of light, allowing the red to shine through – enhancing the “bloody” look of Hind’s Crimson Star. Lepus is in the southeast in early evening, to the lower right of Orion. But you need a telescope to see Hind’s Crimson Star. Script by Damond Benningfield
