Star profile

Kappa Hydrae

Hot blue star

3D likeness based on its real data · class B · ~15,000 K

What is Kappa Hydrae

Kappa Hydrae is a bluish B-type star some 436 light-years away —hot, young, and far more luminous than the Sun despite its modest apparent brightness. It rests upon the back of the sky's longest serpent, in a stretch of the constellation crossing the frontier between the spring constellations. Its cool light is the echo of nuclear processes far more energetic than those of the star that lights our days.

Where it is and when to see it

Kappa Hydrae lies in the southern celestial hemisphere. It is visible to the naked eye under a dark sky. Its best month of the year is February, when it culminates around midnight.

From London it culminates about 24° above the horizon.
From New York it culminates about 35° above the horizon.
From Sydney it culminates about 70° above the horizon.

It can be seen from anywhere south of 76° N.

It ranks no. 46 in brightness among the 121 stars of Hydra in our catalogue. To find it, start from Alphard, the brightest: it lies about 6° away (a fist at arm's length covers about 10°).

The light you see today left it about 440 years ago.

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Astronomical data for Kappa Hydrae

Constellation: Hydra
Apparent magnitude: 5.07
Distance: 436.1 light years
Coordinates (J2000): RA 145.077° · Dec -14.332°
Catalogue: HIP 47452 · HD 83754

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Other stars in Hydra

Hydra has 121 stars in Stelvia's catalogue. Here are a few of them.

See all 121 stars in Hydra