Brightest Stars

Lonely Alphard is the brightest star in Hydra

A long string of stars rising over a horizon, linked by lines, with a bright, orange star in the middle.
On March evenings, you’ll find Hydra the Water Snake ascending in the east. It is the longest constellation in the sky and isn’t fully up until late evenings in April. Alphard – sometimes called Cor Hydrae or Hydra’s Heart – is the brightest star in Hydra. Photo copyright by Till Credner at via Wikimedia Commons (CC BY-SA 3.0).

Alphard (Alpha Hydrae) is the brightest star in the largest constellation in the sky, Hydra the Water Snake. Despite its long length, Hydra’s stars are mostly dim except for Alphard. You will need a very dark sky to see them. Meanwhile, Alphard shines at 2nd-magnitude. So it’s about as bright as the stars of the Big Dipper.

Known as the Heart of the Snake, Alphard is a precursor of spring for us in the Northern Hemisphere.

EarthSky lunar calendars are back in stock! And we’re guaranteed to sell out, so get one while you can. Your support means the world to us and allows us to keep going. Purchase here.

Alphard brings spring

Alphard’s warm orange color and location in the constellation’s core makes it a good representative for the Snake’s Heart. There is something about Alphard – some combination of its orange color and not-too-showy brightness – that looks friendly.

Like so many skywatchers before you, you’ll love seeing Alphard ascend in the early evening in late February and March as it ushers in a new season. Alphard is located in the upper part of the Water Snake. It has risen when darkness falls by the time of the March equinox.

The constellation is so long that the entire snake doesn’t rise until after midnight in March. Alphard heralds the rest of the snake, which ascends in the sky like a cobra from a snake charmer’s basket. On March, April and May evenings, this great star pattern stretches across a huge portion of the sky, from southeast to southwest above the Milky Way.

White chart with black dots for stars and long crooked line for constellation Hydra
Hydra the Water Snake is the longest of the 88 constellations. It extends all the way from Cancer the Crab, below Leo the Lion, to the end of Virgo the Maiden. Image via IAU/ Wikimedia Commons (CC BY 3.0).

How to find Hydra and Alphard

Do you know the constellation Leo the Lion and its famous asterism – the Sickle – shaped like a backward question mark? If so – on an evening in March, April, or May – look for the distinctive backward question mark shape of its head and the triangle body. Then, from Northern Hemisphere locations, look southward to Leo’s lower right to find Alphard.

You’ll find Alphard not far from Regulus, Leo’s brightest star. Alphard is not as bright as Regulus, but it’s a distinctive orange color. Both Alphard and Regulus are known as the “heart” of their respective animal constellations.

Dots and lines outlining lion-shaped constellation with star Alphard lower right.
If you’re in the Northern Hemisphere – and you stand facing southward on a spring evening – Leo the Lion will be over your head. Alphard will be to the lower right of Regulus, Leo’s brightest star.

The solitary one

Much like Fomalhaut six months from now, 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 intrinsically brighter than any of these stars. Yet it appears fainter, because it lies some 177 light-years away, while Pollux, Arcturus and Aldebaran reside at 34, 37, and 65 light-years away, respectively.

Bottom line: Alphard is the “heart” and brightest star in the constellation Hydra, and it represents a welcome sign of spring for the Northern Hemisphere.

Enjoying EarthSky so far? Sign up for our free daily newsletter today!

March 4, 2024
Brightest Stars

Like what you read?
Subscribe and receive daily news delivered to your inbox.

Your email address will only be used for EarthSky content. Privacy Policy
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.

More from 

Bruce McClure

View All