Glossary term: Leo
Description: Leo, "the Lion", is a constellation in the Zodiac, i.e. the stars that make up this constellation are in the part of the sky that intersects with the ecliptic (the plane defined by the Earth's path around the Sun). Hence, from our point of view here on Earth, we can regularly find the Sun, and also the other planets in our Solar System, in this constellation – in the case of the Sun from August 11 to September 17. (Of course if the Sun is there, we cannot see the constellation's stars.) In the night sky, Leo is easiest to observe in spring. It is one of the 88 modern constellations defined by the International Astronomical Union, and also one of the 48 classical constellations named by 2nd century astronomer Claudius Ptolemy. The brightest of Leo's numerous bright stars is called Regulus.
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Term and definition status: This term and its definition have been approved by a research astronomer and a teacher
The OAE Multilingual Glossary is a project of the IAU Office of Astronomy for Education (OAE) in collaboration with the IAU Office of Astronomy Outreach (OAO). The terms and definitions were chosen, written and reviewed by a collective effort from the OAE, the OAE Centers and Nodes, the OAE National Astronomy Education Coordinators (NAECs) and other volunteers. You can find a full list of credits here. All glossary terms and their definitions are released under a Creative Commons CC BY-4.0 license and should be credited to "IAU OAE".
Related Diagrams
Cancer Constellation Map
Credit: Adapted by the IAU Office of Astronomy for Education from the original by IAU/Sky & Telescope
License: CC-BY-4.0 Creative Commons Attribution 4.0 International (CC BY 4.0) icons
Leo Constellation Map
Credit: Adapted by the IAU Office of Astronomy for Education from the original by IAU/Sky & Telescope
License: CC-BY-4.0 Creative Commons Attribution 4.0 International (CC BY 4.0) icons
Virgo Constellation Map
Credit: Adapted by the IAU Office of Astronomy for Education from the original by IAU/Sky & Telescope
License: CC-BY-4.0 Creative Commons Attribution 4.0 International (CC BY 4.0) icons