2101–2120 of 2,250 results
Hipparcos satellite

Celestial Objects to Observe

Mining Hipparcos's Buried Treasure

The satellite caught tantalizing pieces of light curves for many new variable stars. Now it's time to fill in the details.

Celestial Objects to Observe

Solar Filters for Safe Sun Observing

Before an eclipse occurs the media often provides information on how to watch the event safely. Unfortunately, despite the best intentions, inaccurate or confusing information on safe observing techniques is often provided. Here are the facts.

Sunspots across the solar face

Sun

How to Sketch Sunspots Using Projection

Looking for a daytime astronomy project to pursue? Why not set your sights on our nearest star?

Celestial Objects to Observe

Nova Hunters

Few observers have spotted an ever-elusive "new" star. Fewer still have done it twice. Observing styles and techniques are as varied as the searchers themselves.

Celestial Objects to Observe

The Benson Prize

If saving the Earth from destruction isn't enough incentive to find near-Earth asteroids, there's a prize for the amateur who discovers one.

Binary star artwork

Variable Stars

A Treasure-Trove of Variable Stars

Some of the Hipparcos satellite's unfinished business provides fair game for backyard observers.

Variable Stars

The Minima of Algol

Now you can calculate the dates and times (local and Universal Times) when the eclipsing variable star Algol should be at its dimmest (magnitude 3.4 instead of its usual 2.1).

The constellation Leo

Variable Stars

The Lure of Variable Stars

Studying and recording the ups and downs of variable stars is a pleasant pastime that can also be scientifically rewarding. Here's a simple project to get you going.

Celestial Objects to Observe

Phenomena of Jupiter's Moons

Virtually any telescope will show Jupiter's four Galilean satellites and their interesting interactions with the planet or its shadow.

Sketch of Jupiter

Celestial Objects to Observe

Jupiter: The Ultimate Observing Guide

Viewing the solar system¹s largest planet can be more than fun — even with a modest telescope, you can make observations of lasting scientific value.

Deep Sky

A Galaxy-Hop in Leo

Even with a modest telescope and a poor sky, you can ferret out many faint, far galactic wonders by using a good map.

Celestial Objects to Observe

A Chain of Galaxies Near M92

Many interesting but faint objects are often overlooked when they're beside a "showpiece" object. A collection of galaxies near M92 are a good example of this.

Deep Sky

A Pair of Grand Galaxies

If you think all galaxies are faint, fuzzy blobs, think again. Here are two easily-seen galaxies that will change your mind.

NGC 2440

Deep Sky

A Collection of Bipolar Planetary Nebulae

Butterflies of the Milky Way await scrutiny with telescopes small and large.

The Helix Nebula

Celestial Objects to Observe

Hunting Down the Helix

Despite its dodgy reputation, this planetary nebula is easy to find (for both Northern and Southern Hemisphere observers) if you go about it the right way.

Orion Nebula

Deep Sky

A Pair of Nice Nebulae

When you leave the planets, moons, and comets of our solar system behind, you enter the realm of the deep sky, a place of subtle glows and faint lights.

Comin' our way Friday

Asteroids

Hunting Asteroids From Your Backyard

You can discover an asteroid tonight. Digital technology and the CCD revolution have given amateurs the ability to do it. Here's how.

Auroral curtain

Auroras

Satisfy Your Auroral Longing

If you don’t live in Alaska or Iceland, you can improve your chances of seeing an aurora — and maximize your amount of sleep — by monitoring the level of geomagnetic activity.

Celestial Objects to Observe

Observing Amazing Nebulae Season by Season

Nebulae are among the most beautiful sights in the night sky but their diffuse nature can make them challenging to locate. Here are a few interesting nebulae, and most are easy to spot.

Celestial Objects to Observe

Clusters of Clusters: Globular Pairings

Globular clusters are more concentrated in the direction of Sagittarius since that's where we find the center of the Milky Way. This area of the sky affords us opportunities to see several of these rich, ancient clusters in close proximity.