Distance of the Stars
Characters:
Theme: Kinematics
Competencies
Mathematical competence in science, technology and engineering
Subjects and year by Educational System
Spain > Physics and chemistry > 3rd ESO > Basic science skills
Spain > Physics and chemistry > 3rd ESO > Interaction
Enunciation
A Cepheid variable is a star that pulsates radially, changing both in temperature and diameter to produce very regular brightness variations with stable periods and amplitudes. These stars were extensively studied by the American astronomer Henrietta Swan Leavitt (1868–1921). We know that Cepheid variables belong to the Large Magellanic Cloud, which is located 158,200 light-years away, and the speed of light in a vacuum is 300,000 km/s. Calculate:
a) The speed of light in m/s.
b) The distance from the Large Magellanic Cloud to Earth in kilometres and meters.
c) The astronomical unit (AU) is a unit of length defined as 149,597,870,700 meters, approximately equal to the average distance between the Earth and the Sun. This definition has been in effect since the General Assembly of the International Astronomical Union (IAU) on August 31, 2012. How many astronomical units (AU) away are the Cepheid variables?
Observations and context
Henrietta Swan Leavitt is part of the group known as the Harvard Computers, a team of women who made significant advances in the classification of astronomical data at the Harvard Observatory from 1877 to 1919 under the direction of Charles Pickering (1846–1919). Among these women were Williamina Fleming, Annie Jump Cannon, and Antonia Maury. From this group emerged one of the most groundbreaking theses in astronomy, written by Cecilia Payne, who demonstrated, contrary to the beliefs of her mentors, that stars were composed primarily of hydrogen. The scientific community at the time dismissively referred to them as "Pickering's Harem." Despite their crucial contributions, their salaries were comparable to those of unskilled workers. Their work was largely overshadowed, with credit often going to their male superiors, particularly Edward Pickering and Edwin Hubble.
Description
This activity's objective is to understand the order of magnitude of the distances between different celestial bodies. It can also be incorporated into Block 1: Scientific Activity, as it provides an opportunity to practice unit conversions.