# Alphard (Alpha Hydrae)

Alphard (Alpha Hydrae) is a star in the constellation Hydra, magnitude 2.0.

**The Solitary One — a lone orange giant at the heart of Hydra, the sea serpent.**

Some stars are known by the company they keep. Alphard is known for having none. Arab astronomers called it al-fard, “the individual”, because no other bright star lies near it; a later catalogue named it Soheil al Fard, rendered in Latin as “the bright solitary one”. Tycho Brahe preferred Cor Hydræ, the heart of Hydra.

Alphard has left the prime of life. About three times the Sun’s mass and some 420 million years old, it has run out of hydrogen in its core and swollen into a giant almost 58 times the Sun’s width. Its surface is cooler than the Sun’s, which gives it its orange colour.

Its light holds a puzzle: a mild excess of barium, which in other stars usually points to a white dwarf companion that once spilled material onto them. Its surface also quivers in rhythms of hours to days, much like the Sun’s, which lets astronomers probe its interior.

Alphard (Alpha Hydrae) is 180 light-years away: the light we see from it set off around 1845, around the time Neptune was discovered.

## Did you know?

- **On a flag and on the road.** Alphard is on the flag of Brazil, standing for Mato Grosso do Sul — and it lent its name to the Toyota Alphard minivan.
- **Part of the Red Bird.** In ancient China it belonged to the great “red bird” of the southern sky, and it is the first star of Xīng Xiù, the Star mansion.

An orange 2nd-magnitude star alone in a stretch of faint ones, south-west of Regulus — the brightest light in sprawling Hydra. With no bright neighbours to confuse it, it is easy to pick out; binoculars deepen its orange.

## When and where to see it

It is best placed in the evening sky around March, when it crosses the meridian at about 10 pm local time (around midnight in February). It can be seen from everywhere south of 81°N and never sets south of 81°S.

At its highest it stands 31° up from 50°N, 46° up from 35°N, 81° up from the equator, 64° up from 35°S.

## Facts

- Type: Star
- Constellation: Hydra
- Designations: Alpha Hydrae, α Hya, 30 Hya, HR 3748, HD 81797, HIP 46390
- Magnitude: 2.0
- Position: RA 9h 27.6m, Dec −8° 40′ (J2000)
- Spectral type: K3IIIa
- Colour: orange-red (B−V 1.45)
- Distance: 180 light-years
- Discovered: Known since antiquity

Open AstroPilot to see when Alphard (Alpha Hydrae) is highest tonight from your location, how easy it is with your telescope or binoculars, and an eyepiece view. https://astropilot.space/object/alphard