Leo Constellation
Leo (The Lion)
Leo is one of the most recognizable constellations in the night sky and one of the 13 ecliptic constellations. Representing a lion, Leo is prominent due to its distinctive shape and its association with several bright stars and fascinating celestial objects. It has been a symbol of strength and royalty throughout history.
Key Features
- Bright Stars: Leo contains several prominent stars that outline the shape of a lion:
- Regulus: The brightest star in Leo, a blue-white main-sequence star, often called the "Heart of the Lion." It is located about 79 light-years away.
- Denebola: The second brightest star, marking the lion's tail. It is a white main-sequence star located about 36 light-years away.
- Algieba: A binary star system that forms part of the lion's mane, consisting of two orange giants.
- Zosma: A white star located along the lion’s back.
- Deep-Sky Objects: Leo is rich in galaxies and clusters:
- Leo Triplet: A group of three spiral galaxies (M65, M66, and NGC 3628) visible in small telescopes.
- Messier 95 (M95): A barred spiral galaxy located near the center of Leo.
- Messier 96 (M96): Another spiral galaxy slightly brighter than M95.
- Messier 105 (M105): An elliptical galaxy accompanied by several smaller galaxies.
Mythological Background
In Greek mythology, Leo represents the Nemean Lion, a fearsome beast with an impenetrable hide. The lion was defeated by Heracles as the first of his Twelve Labors. After slaying the lion, Heracles used its skin as armor, and the lion was placed in the sky by Zeus to commemorate his triumph.
Leo has also been recognized in Babylonian and Egyptian cultures, where it symbolized power and was associated with the Sun during its highest point in the sky.
Cultural Significance
Leo’s bright stars and prominent position along the ecliptic have made it a key constellation for tracking celestial events. Its association with royalty and strength has been reflected in various cultures, and its shape has been easily identifiable since ancient times. During spring in the Northern Hemisphere, Leo dominates the evening sky, making it a favorite for observers.
Leo Rise and Set Timetable
| Time | Elevation | |
| Moon Rise, 51.4% illuminated | 12:50 | -18° |
| Leo Rise | 14:39 | |
| Sunset | 20:28 | 62° |
| Civil sunset | 20:59 | 64° |
| Leo Transit | 21:31 | 65° |
| Moon Set | 03:22 | 11° |
| Leo Set | 04:22 | |
| Astrosession end | 05:20 | -10° |
| Astrosession begin | 05:41 | -14° |
Track Leo Position Throughout the Night
← Mon, 5 May 2025 →
| Time | |
| Altitude | |
| Azimuth |
Annual motion of Leo
| Date | Tue, 6 May 2025 |
| Twighlight start | 22:12 |
| Twighlight end | 04:35 |
| Twighlight duration | 6h 23m |
| Rise | 14:35 |
| Set | 04:18 |
| Elevation at transit | 65° |
| Transit time | 21:27 |
| Equatorial coordinates | RA: 10h 51m 55s", Dec: 15° 09' 10s |
| Magnitude | - |
| Constellation |
The graph is structured with the vertical axis showing the hours of the day, ranging from 12 AM to 12 AM the next day, while the horizontal axis spans each day of the year.
The reddish shaded area indicates the periods when the Leo is above the horizon, visible to observers. The white line marks the times when the celestial object reaches its highest point in the sky each day, known as the transit.
Acknowledgements
We gratefully acknowledge the International Astronomical Union (IAU) for defining and standardizing the official constellation boundaries, which provide a consistent framework for celestial mapping.
Special thanks to Sky & Telescope Magazine and contributors Roger Sinnott and Rick Fienberg for their collaboration in producing the charts and tables. The constellation patterns, drawn by Alan MacRobert, were influenced by the work of H. A. Rey and thoughtfully adjusted to align with earlier traditions.