The constellation Leo

Characteristics

Other names / Symbolism
Lion
Hemisphere
Both Hemispheres
Visibility
October - May
Area
947 deg²
Brightest star
Regulus (HIP number 49669)
Specialties
Galaxies
The constellation Leo

The Leo, Latin for Lion, is mainly known from astrology as it is one of the 12 zodiac signs. It is also one of the 48 constellations described by the Greco-Roman astronomer in ancient times. In its area are several interesting deep-sky objects that can be observed.

Hemisphere, visibility, and area

The constellation Leo stretches across the celestial equator and is, therefore, visible in both hemispheres. It can be seen from 84° N to 58° S. In northern regions of Greenland and some island groups, it is invisible. In the southern hemisphere, it can be observed as far south as the southernmost point of Patagonia and a few nautical miles further south. It is only not visible from Antarctica and the surrounding islands.

The best time to observe Leo in the night sky is from October to May, with April and May offering a particularly good view of the constellation.

As Leo is located on the ecliptic, the sun passes through the constellation every year from August 11th to September 17th. At this time, the constellation cannot be seen as it rises and sets with the sun on the horizon.

Compared to the zodiac sign Leo, which is assigned to people born between July 23rd and August 23rd, the path of the sun is now shifted by about one month due to the precession of the earth.

Leo covers an area of about 947 square degrees and is therefore ranked 12th among all 88 constellations.

In the area of the constellation, there are some striking stars, with the brightest of them being Regulus (Latin: α Leonis, Alpha Leonis) with an apparent magnitude of roughly 1.36. It forms the well-known Spring Triangle with the stars Spica and Arcturus.

The Leo constellation is surrounded by nine neighbors. The Cancer and Virgo constellations border along the ecliptic. Other neighbors include the Leo Minor, the Hydra, and the Sextans. The Crater, Coma Berenices, and Ursa Major (well-known as Great Bear or Big Dipper) are also adjacent constellations. Additionally, Lynx is located next to Leo.

Specialties in the constellation

There are a number of galaxies in the area of the constellation Leo.

M65 (Messier 65) and M66 (Messier 66) are two of them. They were discovered by the French astronomer Charles Messier in March 1780. Together with another galaxy, they form the so-called Leo Triplet, the core of the M66 galaxy group. Their distance is estimated to be around 30 million light-years from earth.

Even in a large and bright binoculars, the individual galaxies can be perceived. The group is located southeast of the star Chertan.

Leo Triplet with M65, M66 and NGC 3628
Leo Triplet with M65, M66 and NGC 3628

Mythology and history

The first interpretation of the constellation dates back to ancient Egypt. At that time, when the sun passed through the constellation every year, the lions simultaneously migrated from the desert to the sandbanks of the Nile. Therefore, various ancient people saw a lion in the constellation.

In Greek mythology, the lion is mentioned in connection with the hero Hercules. The constellation is said to represent the Nemean Lion, which plagued humans and the environment near the city of Nemea in Corinth.

According to legend, Hercules was tasked with killing the lion as the first of his twelve impossible tasks. However, his attempt to shoot the animal with arrows failed miserably, as the lion was equipped with a unique fur that made him invulnerable.

But Hercules did not give up and eventually managed to strangle the lion. He then used the lion's own claw to slit its skin and wore it as a protective mantle from then on. At the request of Hera, Zeus set the lion as a constellation in the sky.

Constellation Visibility Tool

Los Angeles, USA

34.05°, -118.24°

Constellation Observing Guide

This guide shows when the constellation is visible above the horizon and provides the optimal viewing window when the sky is darkest. Times are displayed in the location's timezone (PDT).

🎯 Best Observing Window

Optimal time when the constellation is fully visible AND the sky is at its darkest. Perfect for telescopic observations, astrophotography, and viewing faint details.

Optimal start

21:13

Jun 3, 21:13

Optimal end

00:46

Jun 4, 00:46

Duration

3.55h

Prime observing time

✨ Perfect Observing Conditions

This is the overlap when the constellation is above horizon AND the sky is at its darkest. Ideal for telescopic observations and photography.

Constellation Visibility from Your Location

6

Visible Stars

0

Never Rise

0

Always Up

100%

Visible

Constellation Completeness6 of 6 stars

All stars of this constellation can be observed from your location

Constellation Visibility

When the constellation is above the horizon (includes daylight hours)

Rises

When the first star of the constellation rises

N/A

N/A

Fully Up

All stars of the constellation are visible

N/A

Starts Setting

When the first star of the constellation settles below the horizon

00:46

Jun 4

Fully Set

When all stars are below the horizon

02:33

Jun 4

Above Horizon Times

Includes daylight hours when stars aren't visible to naked eye.

Astronomical Night

When the sky is darkest (sun >18° below horizon)

Dark sky begins

21:13

Jun 3

Dark sky ends

04:43

Jun 4

Darkest Sky Period

Sun more than 18° below horizon. Best for faint objects.

Observing Tips

Use the optimal window for best results
Check weather conditions before observing
Allow 20+ minutes for dark adaptation
Find a location away from city lights
Times shown in America/Los_Angeles (PDT)
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