This week on Looking Up guest host Caitlyn Voige illuminates a luminary by the name of Henrietta Swan Leavitt. When we look up into the night sky, stars look immeasurably small and distant, unchanging ...

The simple answer is that the intrinsic brightness of these variable stars is strongly tied to their period. This is the famous period-luminosity relationship discovered by Henrietta Leavitt more than ...

Imagine you are standing outside on a clear night, looking up at the sky. When you look at the night sky, some stars appear as faint dots, while others shine so brightly that they light up the ...

A standard candle is an object whose luminosity, or brightness, is a known quantity. Standard candles are used by astronomers to estimate the distance of the candle itself, as well as nearby features, ...

Hubble proved Andromeda is a separate galaxy by identifying a Cepheid variable star within it. Cepheid variables have a period-luminosity relationship: longer period means greater brightness. Knowing ...

Quasars, the luminous beacons at the centers of distant galaxies, have puzzled astronomers for decades with their dramatic brightness variations. Recent observations suggest that these celestial ...

High-brightness LEDs, or HB-LEDs, are semiconductor-based devices that feature higher luminosity than traditional LEDs, and they can withstand higher current levels and power dissipation. These LEDs ...

Flagstaff, Ariz. — For the first time, astronomers have collected and analyzed a long-term set of activity and brightness measurements of a “solar twin.” A team from Lowell Observatory and Tennessee ...