A Pair of Kings

Stargazers will get the royal treatment throughout May thanks to two very different kings. First, Jupiter, the king of the gods in Roman mythology, will shine brightly in our skies, so it’s a perfect time to observe the largest planet in our solar system. Second, a lion, the king of the jungle, will also be easily visible as Leo, one of our oldest constellations, culminates in the early evening. All hail the kings!

The lion king

As archeological evidence shows, the zodiacal constellation Leo is very old. Many ancient civilizations (Mesopotamian, Persian, Indian) referred to this group of stars. In every case, the sickle-shaped asterism within the constellation represented a lion’s head.

For the Sumerians, the constellation depicted Humbaba, a lion-faced monster. Raised by the Sun god Utu, it guarded the forest home of the other gods. For the Greeks and Romans, the constellation represented the Nemean Lion that Hercules slew in the first of his 12 labours.

Leo has played a vital role in the zodiac ever since this system was created. In 2000 BC, the Sun was found in Leo on the summer solstice. Today, Leo is one of the constellations most resembling the figure it represents. The sickle forms the lion’s head, while the three nearby stars on the left make up its body. The leftmost star is called Denebola (“lion’s tail” in Arabic).

At the base of the sickle is Leo’s brightest star, Regulus (“little king” in Latin). This bluish star is 77 light-years away, has a diameter four times larger than the Sun’s, and emits much more energy than our star. Since Regulus lies near the ecliptic, the Moon and the planets of the solar system regularly approach the star and sometimes even block it out.

The crown jewel in the constellation, however, is at the centre of the sickle. Gamma Leonis, also named Algieba (“lion’s mane”), is a magnificent golden binary star whose components are equally bright. You can admire this stellar system through a small telescope.

The king of the gods

Known since ancient times, Jupiter is easily visible to the naked eye in the southeast at sunset. You can observe the planet every night this month, so turn your telescope its way. A gibbous Moon joins Jupiter on the evening of May 7.

The bright planet is named after the Roman god of heaven and earth and the king of all the gods. The Babylonians used Jupiter to map out the zodiac, the belt of the heavens along the ecliptic that is divided into 12 constellations. Jupiter takes 12 years to go around the Sun, and seen from Earth, it also takes 12 years to travel along the zodiac (at a rate of one constellation a year on average).

For night owls, Saturn becomes visible above the southeastern horizon in the second half of the night. Located in the constellation Sagittarius, the ringed planet is joined by a gibbous Moon on the night between May 13 and 14.

For early birds, Venus shines brightly in the dawn sky to the east. A crescent Moon accompanies the planet as it rises on the morning of May 22.