BAS Observer July 2017

JULY 2017 13 Constellation of the month: Scorpius The constellation Scorpius (the Scorpion) sits near the central bulge region of our Milky Way Galaxy. This means it is a good place to find globular clusters attracted to the gravitational mass of the centre of the galaxy. In this one constellation there are about ten globular clusters that can be seen through amateur telescopes, plus another six or more that are much more challenging. Globular cluster Messier 4, located about 7300 light-years away, is an impressive, fuzzy ball of stars very close to the bright‑orange star Antares. This makes it easy to find. Another great telescope target is open cluster Messier 7, located near the curled sting of the Scorpion. This cluster is visible to the naked eye and contains dozens of bright stars. It is located 9 80 light-years from the Sun and is commonly known as Ptolemy’s Cluster, after the ancient Greek astronomer. The planets Jupiter has just about done its dash across the sky and is getting lower in the hazy-evening western sky. Take a last look while you can. Saturn is high overhead and well placed for observing through a minimum of Earth’s turbulent atmosphere. Small, pale-blue Neptune is rising in the evening eastern sky but often looks like just one more star. Make sure you have current finder charts on hand when seeking out distant Neptune. Observing targets: • Messier 4 – globular cluster • Messier 7 – open cluster • The focus is still Jupiter and Saturn. •  Jupiter is still in Virgo but heading for the western horizon. •  Saturn is high overhead in Ophiuchus. •  Neptune is rising in the early evening but is difficult to locate in Aquarius. Jupiter Saturn Neptune