Microlensing

Definition

Microlensing is a gravitational lensing effect where a massive object, such as a star or planet, passes between an observer and a distant light source, temporarily magnifying the light from the source. This phenomenon is used to detect objects that emit little or no light, such as dark matter and exoplanets.

5 Must Know Facts For Your Next Test

1. Microlensing occurs due to the gravitational field of an intervening object bending light from a background source.
2. This effect can be used to detect dark matter by observing its influence on visible stars.
3. Microlensing events are rare and typically last from days to weeks.
4. The amount of light magnification during microlensing provides information about the mass of the intervening object.
5. Microlensing does not depend on the background source emitting its own light, making it useful for detecting non-luminous objects.

Review Questions

• What causes microlensing and what kind of objects can it help detect?
• How does microlensing contribute to our understanding of dark matter?
• What is the typical duration of a microlensing event?

Related terms

Gravitational Lensing:

A phenomenon where the gravitational field of a massive object bends and magnifies the light from another object behind it.

Dark Matter:

A type of matter that does not emit light or energy, detectable only through its gravitational effects.

Exoplanet: A planet located outside our solar system, often detected through various methods including microlensing.