SUNSET: 
The Giant Star That "Blinked"
Astronomers are trying to understand why a giant star "blinked," fading almost completely before brightening again over the course of about 200 days.
Astronomy and Stargazing Projects
Take a Roller Coaster Ride with Algol, a Fast Eclipsing Binary
How would you like to see a star drop two magnitudes in the time it takes to eat dinner? Easy to do. Just check out one of these fast eclipsing binaries — they'll make your head spin.
The Fall and Rise of Betelgeuse
With its recent uptick in brightness, Betelgeuse appears to be slowly returning to normal. But will it? Astronomers urge us to keep watch.
Mark Your Calendar: Stellar Fireworks Predicted for 2083
According to Bradley Schaefer (Louisiana State University), the 11th-magnitude variable star, V Sagittae, will outshine Sirius and maybe even Venus — despite its distance of some 7,500 light-years.
Betelgeuse is Dimming . . . Why?
The bright star Betelgeuse has faded to a historic low as astronomers try to figure out why.
Are There More Stars Like Boyajian’s Star?
Remember KIC 8462852, better known as Boyajian’s star (or you may have seen it referred to as the “alien megastructure” star)? We still don’t have a definitive explanation for this source’s odd behavior — in part because we thought that Boyajian’s star was one-of-a-kind.
From Lunar Flashes to Variable Stars: Pro-Am Astronomy Projects
Track satellites, spot flashes on the Moon, monitor violent stars — learn how amateur astronomers can become involved in professional science.
Hunting Bright Variable Stars in M5 and M13
Globular clusters are packed with variable stars, some of which are easy to see and follow in amateur telescopes. We explore M5 and M13, two of the season's finest.
Mira Makes January Nights "Wonderful"
Mira, one of the easiest-to-observe pulsating variable stars, reaches peak brightness this month. Don't be shy, come look her in the eye.
Aboriginal Australians Observed Red Giant Stars’ Variability
New interpretations of oral accounts by Aboriginal Australians show that they included references to the variability of red giants Antares, Betelgeuse, and Aldebaran.
Explore the Night with Bob King
Plant Your Eyes In Delta Cephei's Fertile Triangle
The famous variable star Delta Cephei unlocks a box deep-sky treasures in a little-visited corner of Cepheus, the King.
Amateurs Help Discover Pulsing White Dwarf
Amateur astronomers worked together with the pros in the discovery of the pulsing white dwarf in the variable system known as AR Scorpii. Hear from Josch Hambsch, one of the amateurs on the team, on what it was like to take part.
Explore the Night with Bob King
Violent Lights For September Nights
Find out how two closely-orbiting stellar pairs create fireworks you can see in your own backyard telescope.
Meet My Variable Friend SS Cygni
Get acquainted with SS Cygni, the sky's brightest cataclysmic variable star. It's guaranteed to keep you on your toes.
The Chaotic Music of Variable Stars
Space-based observations of RR Lyrae variable stars, once considered the paragon of simplicity, are revealing turmoil in their daily vibrations.
Surprise Variable Stars
Astronomers have discovered an unexpected class of variable stars in the open cluster NGC 3766. The stars are problematic for current theories of star behavior and raise perplexing questions about why the stars are variable at all.
Amateurs Monitor Controversial Variable Star
SS Cygni, one of the most-watched variable stars, lies at a distance that’s hotly disputed. The truth will determine whether we understand how these types of variables work.
Yet Another Nova in Sagittarius
For the fourth time this year, a star has erupted into prominence in the same constellation. This one is relatively bright and easy to spot from your backyard.
Possible Nova in Sagittarius
If you've got a clear, dark view toward the southern horizon, try your hand at spotting a flaring star that has brightened to near 9th magnitude in northwest Sagittarius.
Vast New Trove of Variable Stars
Newly online: light curves for 198 million stars. The latest great mass of variable-star data comes from the Catalina Sky Survey — which is actually looking for asteroids.