How did a Cepheid variable star help Edwin Hubble prove the Andromeda Nebula was a galaxy? Roger Brady San Quentin, California Cepheids are rare variable stars with periods ranging from about 1 to 120 ...

The most obvious one is astronomers’ use of the word metal to mean any element heavier than helium. Using a single term to ...

On New Year’s Day, 1925, attendees at an astronomical conference heard one of the most influential scientific presentations of all time. It proved the Andromeda Nebula is immensely distant from Earth, ...

Soon after sunset, as the sky gets dark, look toward the south and youll immediately notice the brilliant planet Jupiter, but there's another night sky target that also promises a great experience: ...

How would you like to see the farthest thing visible to the naked eye? It’s possible, but you’ll need to bundle up and sit back on a lawn chair. Your neighbors may think you’ve cracked up sitting out ...

One of astronomy’s deepest mysteries is the “radio star,” an object in space that “shines” with radio waves instead of with .visible light. The first radio stars were discovered only about two years ...

The article details various types of deep-sky objects observable by amateur astronomers, including double stars, variable stars, open and globular star clusters, emission, planetary, and reflection ...

"Beyond the Milky Way lie billions of other galaxies, drifting a few million light years from one another like lily pads floating on the surface of a pond." — Timothy Ferris in Seeing in the Dark A ...

One of the more interesting features of the late summer and early autumn Colorado sky is the faint band of light that now stretches from Sagittarius in the southwest to Perseus in the northeast and ...

Andromeda is one of the 88 modern constellations that was likely known and named long before it appeared on Ptolemy’s list in the second century CE. But my experience is that more people associate the ...

How would you like to see the farthest thing visible to the naked eye? It’s possible, but you’ll need to bundle up and sit back on a lawn chair. Your neighbors may think you’ve cracked up sitting out ...