Today we’ll look at a pattern of stars, a grouping known as an asterism, that heralds the season of spring.
In the northern hemisphere, this asterism is known as the Spring Triangle, but for those in the southern hemisphere, Autumn Triangle would be more appropriate. It is formed by three bright stars in three constellations that are prominent at this time of year.
The stars are Arcturus in Boötes, the herdsman; Spica in Virgo, the virgin; and Regulus in Leo, the lion. The chart shows the view looking south from London at 22:00BST on Monday evening, and it will essentially remain unchanged all week.
Look for the colour of the three stars, which betrays their surface temperature. Arcturus is orange, with a surface temperature of about 4,200K (3,930C). Spica is a brilliant blue-white at about 25,000K and Regulus is white at about 11,500K. From the southern hemisphere, the asterism will appear upside down.
