A kingly star

An old starwatcher's saying goes, 'Poke a hole in the bottom of the dipper's cup and the milk will spill on the lion's back.' Indeed, if you follow an imaginary stream of milk southward from the bottom of the bowl of the Big Dipper, you'll dribble right onto the back of Leo the Lion.

You can't miss Leo this week, especially with his distinctive mane that resembles a sickle (others describe it as a 'backwards question mark'). At the end of the sickle's handle shines a lone jewel, Regulus, a star whose name is a Latin derivative meaning 'the prince,' or as others interpret it, 'the little king.'

Though it is the eighteenth-brightest star in the sky Regulus looks a bit lost, surrounded as it is by darkness and stars far fainter than itself. It ranks in brightness a notch below white Deneb in Cygnus, seen in summer skies, but is brighter than orange-hued Pollux in Gemini, which, even though it is Regulus's nearest bright neighbor in the sky, lies over 30° to the northwest. On a dark night with the star highest in the sky, Regulus looks predominantly white in color, but is tinged with just a hint of blue. Near the horizon, it may appear reddish, because its light bends through a greater thickness of Earth's atmosphere at that altitude.

If you note the comings and goings of Regulus, you'll find that this spring star doesn't belong to any one season. It belongs to them all. Regulus first appears in the sky New Year's evening, winking at us through bare trees around 10 o'clock. By late February, it's in the sky all night, rising when the Sun sets and setting when the Sun rises. Regulus remains visible until mid July, when it sets soon after the Sun. Thereafter, it vanishes in the Sun's glare in the west, but reappears in time for fall's arrival in late September, when it peeks over the eastern horizon just before dawn.

When you get right down to it, there are a number of these 'season-less' stars and even seasonless constellations. For example, another spring star, Arcturus - fourth-brightest star in the sky - appears in the east the first of March at sunset and doesn't vanish from the evening skies until late November. And the summer constellations Cygnus, Lyra, and Aquila hang around in the western sky until well after the first day of winter.

Traditionally, however, bright stars and constellations are associated with the seasons in which they are highest in the sky. Until Arcturus takes the prince's place, followed by the bright stars of summer, Regulus remains the crowning star of spring.

April 19-25

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