Hipparcos

Definition

Hipparcos was a pioneering space astrometry satellite launched by the European Space Agency (ESA) in 1989. It was designed to conduct a highly accurate survey of the positions and motions of stars in our galaxy, providing unprecedented data on stellar parallax and proper motion.

5 Must Know Facts For Your Next Test

1. The Hipparcos satellite operated for nearly 4 years, from 1989 to 1993, and produced the most accurate and comprehensive catalog of stellar positions and motions at the time.
2. Hipparcos measured the parallax of over 100,000 stars, allowing for the calculation of their distances from Earth, which was a significant improvement over previous methods.
3. The Hipparcos catalog provided accurate data on the proper motion of stars, enabling the study of the kinematics and dynamics of our galaxy.
4. The Hipparcos mission revolutionized our understanding of the structure and evolution of the Milky Way by providing high-precision data on the positions, distances, and motions of nearby stars.
5. The Hipparcos data has been widely used in various fields of astronomy, including the study of stellar evolution, the calibration of the cosmic distance scale, and the investigation of the dynamics of our solar system.

Review Questions

• Explain the significance of the Hipparcos mission in the context of surveying the stars.
  • The Hipparcos mission was a groundbreaking effort in the field of astrometry, as it provided the most accurate and comprehensive catalog of stellar positions and motions at the time. By measuring the parallax of over 100,000 stars, Hipparcos enabled the calculation of their distances from Earth, which was a significant improvement over previous methods. This data, along with the precise measurements of stellar proper motion, revolutionized our understanding of the structure and evolution of the Milky Way galaxy, allowing astronomers to study the kinematics and dynamics of nearby stars in unprecedented detail.
• Describe how the Hipparcos mission contributed to the calibration of the cosmic distance scale.
  • The Hipparcos mission played a crucial role in the calibration of the cosmic distance scale, which is essential for understanding the structure and evolution of the universe. By providing highly accurate parallax measurements for a large number of stars, Hipparcos enabled the precise determination of their distances from Earth. This data was then used to calibrate the relationships between various distance indicators, such as the period-luminosity relation of Cepheid variable stars, which are commonly used to measure extragalactic distances. The improved cosmic distance scale derived from the Hipparcos data has had far-reaching implications for our understanding of the size, age, and expansion rate of the universe.
• Analyze how the Hipparcos data has been utilized in the study of stellar evolution and the dynamics of our solar system.
  • The high-precision data from the Hipparcos mission has been extensively used in the study of stellar evolution and the dynamics of our solar system. By providing accurate information on the positions, distances, and motions of nearby stars, the Hipparcos catalog has allowed astronomers to better understand the kinematics and evolution of individual stars, as well as the overall structure and evolution of the Milky Way. This data has been crucial for calibrating theoretical models of stellar evolution, enabling more accurate predictions of the properties and life cycles of different types of stars. Furthermore, the Hipparcos data has been invaluable for investigating the dynamics of our solar system, as the precise measurements of stellar proper motion have helped to refine our understanding of the Sun's motion through the galaxy and the gravitational influences of nearby stars on the orbits of the planets.

Related terms

Parallax: The apparent shift in the position of a nearby object relative to more distant objects, caused by a change in the observer's position. Parallax is used to measure the distances to nearby stars.

Proper Motion: The apparent motion of a star across the celestial sphere, caused by the star's actual motion through space relative to the Sun and other nearby stars.

Astrometry: The branch of astronomy concerned with the precise measurement of the positions and motions of celestial objects, including stars, planets, and other bodies.