Emersion

Emersion

Emersion is a term used in astronomy and astrophysics to describe the reappearance of a celestial body from behind another object, such as a planet, moon, or star. This phenomenon is the opposite of immersion, where the celestial body disappears behind another object. Emersion is commonly observed during events such as occultations, eclipses, and transits.

Occultations

An occultation occurs when one celestial body passes in front of another, temporarily obscuring it from view. During an occultation, the emersion phase is when the obscured body reappears from behind the occulting body. For example, during a lunar occultation of a star, the star will reappear from behind the Moon during the emersion phase.

Eclipses

In the context of eclipses, emersion refers to the moment when the eclipsed body, such as the Sun or Moon, begins to reappear from the shadow of another body. During a solar eclipse, emersion occurs when the Moon moves away from the Sun, allowing the Sun to become visible again. Similarly, during a lunar eclipse, emersion happens when the Earth's shadow moves away from the Moon, making the Moon visible once more.

Transits

A transit occurs when a smaller celestial body passes in front of a larger one, such as when a planet transits across the face of a star. Emersion in this context refers to the moment when the transiting body moves off the disk of the larger body, allowing the larger body to be fully visible again. For example, during a transit of Mercury across the Sun, emersion is the point at which Mercury moves off the Sun's disk.

Related Pages

• Occultation
• Eclipse
• Transit
• Astronomy
• Astrophysics
• Moon
• Sun
• Planet