Having tracked down Jupiter, Saturn and the moon last week, we’re going to stay in this part of the sky for a few weeks and locate some of the fainter constellations. This week, we are going to find a small, faint constellation that is easily overlooked. It is Equuleus, the little horse or foal.
The chart shows the view looking south-east from London on Monday at midnight. Nestled between much larger constellations, Equuleus is undoubtedly tough to find. It will require a dark site, well away from streetlamps, and patience as your eyes adjust to the dark.
The apparent brightness of a star is called its magnitude. The brightest stars are said to be magnitude one. For example, Altair in Aquila, the eagle, is a first-magnitude star. The faintest stars visible to the naked eye are said to be magnitude six. Equuleus contains no stars brighter than magnitude four, so it will take some searching for.
Find the bright orb of Jupiter and look up. Early in the week, the waning gibbous moon does not help, so later towards the weekend might be the best time to look. Equuleus is one of the 48 constellations listed in the 2nd century by Ptolemy, and rather charmingly is located in the sky next to Pegasus, the winged horse.