The Lion
| Abbreviation: | Leo |
| Genitive: | Leonis |
| Origin: | [antiquity] |
| Fully Visible: | 57°S – 83°N |
Leo is a member of the zodiac. This is one of the most ancient of constellations, with the Mesopotamians having a similar constellation 4000 years ago. The Greeks identified it as the Nemean Lion which was killed by Heracles as one of his Twelve Labours.
The asterism of the 'Sickle', looking like a backwards question mark, is comprised of the stars ε Leo, μ Leo, ζ Leo, γ Leo, and η Leo and α Leo.
Notable Features
| Visible Named Stars | ||
|---|---|---|
| α Leo | Regulus | This is the faintest of the first magnitude stars. It sometimes appears as Kalb (from the Arabic al‑kalb al‑asad meaning 'the heart of the lion') in older star atlases and catalogues. In Hindu astronomy, it is known as Magha, from the Sanskrit māgha meaning 'the magnificent'. |
| β Leo | Denebola | This star appears as Al Serpha (from the Arabic al‑ṣarfa meaning 'the weather changer') in Mohammad Al Achsasi Al Mouakket's calendarium. In Hindu astronomy, it is known as Uttara Phalguni, from the Sanskrit uttara phālgunī meaning 'the second reddish one'. It is near CT1133, one of the first pulsars discovered in 1968. |
| γ Leo | Algieba | This star appears as Menkib al Asad (from the Arabic al‑mankib al‑asad meaning 'the shoulder of the lion') in Mohammad Al Achsasi Al Mouakket's calendarium. A telescope will reveal its binary nature. |
| δ Leo | Zosma | This star sometimes appears as Duhr (from the Arabic ẓahr al‑asad meaning 'the back of the lion') in older star atlases and catalogues. In Chinese astronomy, this star is known as Xicixiang, from Xī Cì Xiàng meaning 'the second western minister'. In Hindu astronomy, δ Leo and θ Leo together are known as Purva Phalguni, from the Sanskrit pūrva phālgunī meaning 'the first reddish one'. |
| ζ Leo | Adhafera | Adhafera becomes three unrelated stars when viewed through binoculars. |
| θ Leo | Chertan | This star sometimes appears as Chort or Coxa (from the Latin coxa meaning 'the hip') in older star atlases and catalogues. In Chinese astronomy, this star is known as Xishangxiang, from Xī Shàng Xiàng meaning 'the first western minister'. |
| λ Leo | Alterf | This fourth-magnitude star is a K-type giant. |
| μ Leo | Rasalas | This star sometimes appears as Rasalasad Borealis in older star atlases and catalogues. |
| ο Leo | Subra | This spectroscopic binary has a period of nearly 120 years! |
| HD 100655 | Formosa | Located between Zosma (δ Leo) and 93 Leo, this sixth-magnitude star is known to have at least one exoplanet. |
| Other Interesting Stars | ||
| HD 96063 | Dingolay | This eighth-magnitude star is known to have at least one exoplanet. It is located not far from the border with Sextans. |
| HD 99109 | Shama | This ninth-magnitude star is known to have at least one exoplanet and is found midway between υ Leo and φ Leo. |
| HD 100777 | Sagarmatha | This eighth-magnitude star, the farthest south of all of the named Leonine stars, is known to have at least one exoplanet. |
| Wolf 359 | This star, located near χ Leo, is just under 8 light years away from the Sun, making it one of the the closest stars to the solar system. Despite its proximity, it cannot be seen with the naked eye. | |
| Deep Sky Objects | ||
| M65 | This spiral galaxy appears elliptical through a small telescope. | |
| M66 | Dark dust lanes and bright star clusters along its spiral arms mark out this spiral galaxy. The three spiral galaxies, M65, M66 and nearby NGC 3628 (the 'Hamburger Galaxy'), are known collectively as the 'Leo Triplet'. | |
| M95 | This is a barred spiral galaxy. | |
| M96 | Leo is full of spiral galaxies! | |
| M105 | A massive black hole lurks at the heart of this elliptical galaxy. | |
| C40 | This galaxy (also known as NGC 3632) is located between the stars Chertan (θ Leo) and Zosma (δ Leo). | |
| Meteor Shower Radiants | ||
| 013 LEO | Leonids | This November meteor shower is the fastest of all such events because the meteors are colliding with Earth practically head-on. They can be very bright and most leave trains. Associated with comet 55P/Tempel-Tuttle which reached perihelion in January 1998, this shower was particularly exciting for the next few years. Indeed, this meteor shower is notorious for its intense, periodic storms which occur at 33-year intervals (the period of its associated comet). In 1966, observers in the western United States were treated to the sight of 40 meteors per second! The radiant is in the asterism of the 'Sickle'. |
| 212 KLE | κ Leonids | This daytime radio shower is active in late September. |
Copyright © 1995–2023 by L.M. Stockman and David Harper