June- Prominent Clusters and a Dazzling Double
If you’ve never found a deep-sky object on your own before, M4 is a great place to start. The M4 globular star cluster is easy to find, because it’s right next to the first-magnitude star Antares, the brightest in the constellation Scorpius. Once you spot it, you might begin longing for a telescope to be able to resolve this fuzzy cluster into a group of starry pinpoints.
At low magnification of about 40x you may be able to resolve the cluster with averted vision. Double that magnification and you’ll be able to see a prominent bar of stars that crosses the cluster from north to south.
With the unaided eye, M5 is barely detectable with the appearance of a faint star. Binoculars show it a bit more clearly. M5 appears slightly oval at low power, with a halo that extends about twice as far as the core itself.
But using a small telescope you’ll see one of the finest globular clusters north of the celestial equator. Unlike many of the “faint fuzzies” in the night sky – nebulas, galaxies and clusters that still appear as dim, blurry smudges even through telescopes – M5 is one of the best globular clusters to observe.
Finding Xi Boötes in the sky can be somewhat challenging, especially if observing under light polluted skies. At magnitude 4.6 this star will surely be overpowered by local light pollution. Look for the super bright star Arcturus is in the same neighborhood as Xi Boötes and will serve as a suitable guide. Shortly after sunset, while facing South, the bright yellow star Arcturus will be shining dominantly overhead.
Observations of Xi Boötes will easily reveal distinction between both stars with even modest backyard telescopes due to its relatively wide 7 arcseconds of separation. A noticeable yellow with hints of purple will emit from the luminous primary star with a ruby-red present in the smaller companion star. If the colorful differences in these stars do not present themselves, adjust your focus to slightly blur the view and colors should become apparent.