In skylore, the star Alphard (Alpha Hydrae) represents the orange Heart of the Water Snake in the constellation Hydra. For this reason, it is sometimes called Cor Hydrae or Hydra’s Heart.
Like so many skywatchers before you, you will grow to love seeing Alphard ascending in the southeast in the early evening in spring. Alphard is located in the front part of the Water Snake, and it’s up when darkness falls by the time of the March equinox. The rest of the Water Snake is a long thin constellation made up of dim stars, which can be seen rising throughout spring evenings. The entire Snake isn’t up completely until after midnight in March. So Alphard is like a herald to the rest of the Snake, which ascends in the southeastern sky like a snake charmer’s cobra from a basket. There is something about Alphard – some combination of its orange color and not-too-showy brightness – that looks friendly. And, after all, Alphard is the Heart of Hydra, the Water Snake.
Alphard is the only star of any noteworthy brightness in Hydra, but Hydra itself is distinctive for being the longest of all 88 astronomical constellations. As seen from the Northern Hemisphere, this great star pattern stretches across the entire southern sky on spring evenings.
Do you know the constellation Leo the Lion – and its famous backwards question mark asterism? If so, on a spring evening, look generally overhead for Leo – then southward for Alphard to Leo’s lower right. You will find Alphard not far from Regulus, Leo’s brightest star. Alphard is not as bright as Regulus, but it’s a distinctive orange color.
Alphard shines in the early evening sky, beginning in late February. Springtime evenings (March, April, and May) are the best time to see this star. Alphard isn’t the sky’s brightest star, but it is respectably bright – a second-magnitude star. It shines on a par with the stars of the Big Dipper.
Much like Fomalhaut in autumn, Alphard is said to be a lonely star. It beams as the sole bright light in a sea of dim stars in its part of the sky. The Arabic name Alphard translates as the Solitary One.
Look at Alphard with binoculars to discern its orange color. Alphard’s color shows that it is entering into the autumn of its years, like the color of the orange stars Pollux and Arcturus, and the ruddy star Aldebaran. Old stars’ colors are reminiscent of the orange color of autumn leaves. Like Pollux, Arcturus, and Aldebaran, Alphard will shed its outer layers someday soon (by astronomical standards) and shrink into a dead white dwarf star.
Pollux, Arcturus, and Aldebaran appear brighter in our sky than Alphard, but that’s because they are so much closer to us. Alphard is actually intrinsically brighter than any of these stars. Yet it appears fainter, because it Alphard lies some 180 light-years away, while Pollux, Arcturus, and Aldebaran reside at 34, 37, and 65 light-years, respectively.
Bottom line: In Northern Hemisphere spring (southern autumn), come to know the star Alphard, starry Heart of the Snake in the constellation Hydra.