Bessel

Definition

Friedrich Wilhelm Bessel was a German astronomer and mathematician who made significant contributions to the measurement of stellar distances. He is best known for his work on parallax, which helped determine the distance to stars beyond our solar system.

5 Must Know Facts For Your Next Test

1. Bessel was the first to measure the parallax of a star, specifically 61 Cygni in 1838.
2. His measurements confirmed that stars are incredibly distant from Earth.
3. Bessel's work provided a foundation for modern astrometry by establishing methods to calculate stellar distances.
4. The unit of distance 'parsec' is derived based on principles similar to those used by Bessel in his parallax measurements.
5. Bessel also contributed to the field of mathematics with Bessel functions, which are important in many areas of physics and engineering.

Review Questions

• What was Friedrich Wilhelm Bessel's most notable contribution to astronomy?
• Which star's parallax did Bessel successfully measure in 1838?
• How did Bessel’s work impact the understanding of stellar distances?

Related terms

Parallax: The apparent shift in position of an object when viewed from different perspectives; used in measuring stellar distances.

Parsec: A unit of distance used in astronomy, equivalent to approximately 3.26 light-years.

Astrometry: The branch of astronomy that deals with measuring the positions and movements of celestial bodies.