Observing Venus and Mercury

The Sun has just sunk below the horizon. A gentle spring breeze is blowing. You look up in the west almost halfway up the sky, though it seems even higher. And what you see there is an intense little point of light, visible before any other planet or star. As the sky behind you darkens, and even where the Sun went down pales from a glare to a vibrant but gentle glow, the point of light gets bigger and more prominent. Even by the time full darkness has fallen, and the light has become a truly...

Occultations by Planets

What would be the closest conjunction of planets possible That would be when one looks in the telescope and sees the disk of one planet pass partly or completely in front of the disk of another. Such an event is called a mutual occultation of planets. Only a few of these were known up until the late 1970s, but then my friend Steve Albers was able to calculate more than a dozen between 1557 and 2230. Unfortunately, no mutual occultation of planets occurs between 1818 and 2065 and even the 2065...

The Beauty of a Star

Sadly, many people in modern society have lost touch with the stars in the sky. Certainly light pollution has played a major role in this by degrading our view of stars in and around cities. Whatever the causes, when most people hear the word star now they are likely to think first about entertainment celebrities. Yet, the fact that society calls its most figuratively illustrious and admired of personalities stars suggests that the original stars the enduring ones in the sky were originally...

Sunspots and Faculae

Even with just solar projection it is possible to observe a few of the most important solar features and phenomena. Certainly sunspots sometimes large numbers of them. But you can also notice that the edge of the solar disk seems dimmer than the center. This is not an optical illusion. You are seeing limb darkening. It occurs because near the edge of the Sun there is a longer pathway of gas for light to pass through and therefore a greater amount of gas to dim the light. The darkening of the...

M11 the Wild Duck Cluster

Everyone will have their own favorite cluster in the telescope (or several favorites to suit different moods). My favorite telescopic open cluster is perhaps the only one visible from the northern hemisphere that can really compete with the Double Cluster in raw splendor M11. M11 is only a single, not a double, collection of stars. Its total brightness is considerably less than that of the Double Cluster. But it is much richer than either member of the Double Cluster. On a 1-to-5 scale of...

Constellations of Summer

We discussed Lyra the Lyre, Cygnus the Swan, and Aquila the Eagle as the three best constellations of the Summer Triangle in Sight 10. Also in and around the Summer Triangle are Delphinus the Dolphin, Sagitta the Arrow, Vulpecula the Little Fox, and Scutum the Shield. Even though they are all dim constellations, they contain several superb telescopic objects (read about Scutum's open cluster M11 in Sight 47, Vulpecula's planetary nebula M27 in Sight 49, and the naked-eye Milky Way's Scutum Star...

The Galaxies of Spring

Of course, we've already explored spring's greatest galaxy wonderland the regions of Virgo and Coma Berenices dominated by the Virgo Galaxy Cluster (the Realm of the Galaxies). Back in that chapter (Sight 34), we also looked at a few fascinating galaxies that are in Virgo and Coma Berenices but are not members of the Virgo Cluster needle-thin NGC 4565 and dust-spotted M64, the Black-eye Galaxy. In that chapter, however, I merely mentioned a mighty galaxy that I said may (or may not) be a...