SUNSET: 
Open Clusters by the Season
Open clusters are popular targets for deep-sky observers, particularly when composed of varied-color stars. Here are some treats for scopes both large and small.
A Sampling of Star Clusters
You don't need a big telescope to be dazzled by deep-sky wonders, particularly if your target is one of the many lovely star clusters.
Ancient Thebit and Huygens's Sword
The absolute best example of a lunar fault is the Straight Wall. This well-known lunar feature is a long thin line that never fails to impress; even through a small telescope it's a fascinating sight.
What Is A Blue Moon in Astronomy?
Is Friday's full Moon "blue"? Depends on who you ask, but if someone answers yes, it's because of a mistake in a 1946 issue of Sky & Telescope.
Leading a Double (Star) Life
Double stars show us color combinations we seldom see anywhere else in the sky. Viewing these stellar twins yourself is fun and easy.
Seeing Double (Stars)
Spotting double stars is always a stargazing treat! Here are some targets to get you started.
Orion's Splendid Double Stars
Some of the finest double and multiple stars in the sky are on display as the constellation Orion, the Hunter, comes to prominence.
Pretty Double Stars for Everyone
Double stars can be found everywhere. Here's a selection of pretty doubles vislble when Orion the hunter is riding high in the sky.
More Pretty Double Stars
When the Milky Way is prominent, don't overlook the wealth of pretty double stars visible during this season.
Camcorder Timing Tips
Many households now possess a camcorder. Many amateur astronomers may be unaware that these devices are sensitive enough to record occultation events.
Occultations: The Fastest Things in the Sky
Watch in your telescope as the edge of the Moon snaps a star out of sight.
Southern Double-Star Gems
The treasure-filled skies of the Southern Hemisphere offer observers more than showpiece clusters and nebulae.
Observing Double Stars for Fun and Science
Amateur observations of visual double stars are desperately needed. Here¹s how you can take the plunge.
Why do you need a hydrogen-alpha filter to see solar prominences?
If I can see solar prominences with the naked eye during a total eclipse, why do I need a hydrogen-alpha filter to see them at other times? During a total eclipse the Moon completely blocks the Sun’s photosphere, or visible “surface,” allowing prominences (and the corona) to shine in all…
Take a "Sat-seeing" Tour
It’s a bird! It’s a plane! It’s the International Space Station! Learn how to spot Earth's artificial satellites.
Catch the Green Flash!
It sounds like a comic-book superhero, but this brief spectacle marks the end of daylight with a burst of color.
A Solar Observing Refresher Course
With modest equipment and attention to safety, you can enjoy observational astronomy throughout the day.
R and T Coronae Borealis: Two Stellar Opposites
One is usually bright but fades unexpectedly; one is almost always faint but brightens unexpectedly. Check them out with binoculars.
Observing the Sun Safely: Sunspots, Faculae, and Flares
The surface of the Sun is a dynamic, living place that can change unpredictably from day to day.
Observing the Full Moon
The full Moon is very bright, but there are still many fascinating features to observe during this or any phase when you look far from the terminator.
