Equuleus

What is Equuleus?

Constellations· Autumn evenings (N) · 2nd-smallest constellation, just off Pegasus's nose. The second-smallest constellation: four 4th-magnitude stars form a tiny trapezium just ahead of Enif, the nose of Pegasus, beside Delphinus. A little horse shown only as a head, it is among the oldest constellations, credited to Hipparchus in the 2nd century BC. Zoom in west of Enif in the Sky view.

📍 Visible from where you are right now — computed in your browser

bearing · altitude · rise time · best time tonight

Equuleus
Image: NowSky rendering (an illustration, not a photograph)· Wikipedia
Equuleus star lines
Star lines — the stars used and how they connect (NowSky)

Where Equuleus is in your sky right now: https://nowsky.org/solar/sky?sel=con:Equuleus — location and time set automatically, no login.

Stars of the figure

StarMagnitude
Kitalpha3.9

The 1 brightest of the 2 stars used in the figure (1 lines). Lower magnitude means brighter.

Constellation basics

Seasonautumn evenings (N)
Brightest starKitalpha (α, 3.9)
How to findbetween Enif (Pegasus's nose) and Delphinus
Area rank88 (두 번째로 작음 / 2nd smallest)

Figures are representative approximations. Source: compiled from NASA and IAU public data.

Frequently asked

When can I see Equuleus?
autumn evenings (N).
How do I find Equuleus?
between Enif (Pegasus's nose) and Delphinus.
What is the brightest star in Equuleus?
Kitalpha, magnitude 3.9.
Where is Equuleus in the sky right now?
Open the sky view for your location and time and it shows the position in the sky right now.

Second smallest in the sky — the last box for constellation collectors

Equuleus covers 72 square degrees, the smallest constellation after Crux among the 88. That would hold 300 full moons, yet as constellations go it is the size of a hand, and with only four 4th-magnitude stars it cannot be seen from a city. Among observers who set out to see every constellation for themselves it is usually the last box left, to be found beside the nose of Pegasus on autumn evenings.

In classical myth this little horse is Celeris, Pegasus's brother, or a horse Hermes gave to Castor. One reading of why the figure shows only the head is that there was no more room in the sky. When the boundaries were fixed in 1930 the constellation was settled as a small rectangle left between its neighbours, and it became the quietest name on the list.

The constellation in depth

Equuleus appears in Ptolemy's 48 constellations but is said to have been created earlier by Hipparchus in the 2nd century BC. The Greeks called it "the fore part of the horse", and indeed only the head is drawn. It has been explained as Celeris, the horse Hermes gave to Castor, or as a sibling of Pegasus, but no firm myth survives.

Kitalpha, the alpha star, means "part of the horse" in Arabic and is a yellow giant of magnitude 3.9. Delta Equulei is an extremely close binary orbiting every 5.7 years, for decades the record holder for the shortest period of any pair resolvable in a telescope. Covering just 0.17% of the sky, it is second in smallness only to Crux, and it holds no notable nebulae or galaxies.

On September–November evenings, find Enif, the bright nose star of Pegasus, then shift about 10 degrees west to the little trapezium of four 4th-magnitude stars; the diamond of Delphinus follows further west. Binoculars help in town. Zoom in around Enif in the Sky view.

Related

Figures are representative approximations. Simulated positions use J2000 mean elements.