Transiten

Transiten is a plural form used in several languages, corresponding to the English term transit. It denotes events or processes in which an object moves through a region, across a disk, or along a line of sight. The precise meaning depends on the field, but the common thread is passage and alignment.

In astronomy, a transit is the apparent passage of one celestial body across the disk of another as seen from a given observer. Planetary transits, such as Mercury or Venus crossing the Sun, are well known examples. Transits are distinct from occultations, where the foreground body disappears behind another object. Transit observations often rely on precise timing and long-term monitoring to measure the size and orbital period of the body.

One major application is the transit method for discovering exoplanets. When a planet crosses its host star, it causes a small, periodic dip in brightness that flags a planet's presence. The depth of the dip yields the planet's radius, while periodicity gives the orbital period. Combined with radial-velocity measurements, transits can also constrain planetary density.

Public transit encompasses shared transportation services such as buses, subways, trams, and ferries that move many people along fixed routes. Transit systems require schedules, fare systems, and infrastructure like stations and tracks. Effective transit improves mobility, reduces road congestion, and lowers emissions, making it a central concern in urban planning.

In physiology, gastrointestinal transit describes the movement of contents through the digestive tract. Gastrointestinal transit time is a key measure of gut motility and can be assessed with markers, imaging, or wireless devices. Abnormal transit is associated with disorders such as constipation, diarrhea, and dysmotility.

In astrology, planetary transits refer to the ongoing positions of planets relative to a birth chart and are used to interpret potential life themes. This application is non-scientific and considered a belief system.