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Hi. It is a pleasure to help. If you mean the distance from the earth to the stars, astronomers use a technique called parallax which is a way to infer the distance to a star based on triangulation. Astronomers use a unit called the light-year, which is the distance travelled by the light in one year. Since light travels at a speed of 300,000 km/s, in one year light leaves behind a distance of 9.4605284 × 1015 meters. Some stars are only a few light- years away. Others are very far away, in the limits of the observable universe. If the astronomer wants to measure the distance to a very far away star, then parallax is no longer useful. Other techniques and properties are employed such as the Cepheids, which are a very particular class of stars in which the period of variation in their brightness is related to their distances. So by measuring the period, astronomers are able to infer the distance.
Measuring distances to stars and to distant galaxies is one of the central problems in Astronomy. It is VERY important. Several research efforts are devoted to measuring distances. In fact, in the 1920's E. Hubble first measured the distance to other galaxies using cepheids. The Hubble Sapce Telescope still measures distances to distant galaxies using a variety of observational techniques.
If you mean the measurement of the radius of a star, astronomers do that by knowing the details of the cameras used to photograph the star and the known distance to it. Sometimes studying the properties of the light emitted by stars it is possible to infer its radius based on the theory of stellar evolution.
Prof. João Rodrigo Leão
Rio Grande Federal University - Brazil
What else can I help you with?
How do you you use astrolabe in a sentence?
The scientist used an astrolabe to find the altitude of the sun and stars.
How do astronomers measure the distance to nearby stars?
Astronomers use a method called parallax to measure the distance to nearby stars. By observing how a star's position changes when viewed from different points in Earth's orbit around the Sun, astronomers can calculate the star's distance based on the angle of this apparent shift.
What unit of measurement do astronomers use to measure the size of stars?
I have usually seen them quoted in kilometers.
What is one way scientist use to calculate the age of the universe?
One way scientists use to calculate the age of the universe is by measuring the rate of expansion of the universe since the Big Bang. By studying the cosmic microwave background radiation, astronomers can determine the age of the universe to be about 13.8 billion years.
How do astronomers study the motion of stars, particularly when observing a line of stars moving in a straight line?
Astronomers study the motion of stars by observing their positions over time. When observing a line of stars moving in a straight line, astronomers track the stars' positions and measure their velocities to understand their motion.
The instruments scientist use to record the measurements?
beaker to measure the amount of water the weighing scale a ruler thermometer etc.
What would scientist most likely use to measure the length of a nail or another small object?
A scientist would most likely use a ruler or caliper to measure the length of a nail or other small object. These tools provide accurate measurements in centimeters or inches.
What has replaced the use of stars in geodetic measurements?
The use of stars in geodetic measurements has been replaced by GPS satellites.
Why must scientist use standard units of measure in their experiments?
They have to use standard units of measurements in their expirements, so they can commpare data
What system do scientist use to take measurements?
rulers you idiete
What process do scientist use to measure the distance of stars?
They use a complicated kind of trigonometry, looking at the apparent distance, light, and other different factors to calculate it.
How do you find an exoplanet?
Scientist use extremely powerful telescopes and machines to measure the brightness of stars. If a planet were to pass in front of the star than the stars brightness may dip by 1/1000th of a percent. The telescopes are so powerful that they are able to measure this dip and thus allow scientist to detect exoplanets.
What do scientist use rulers for?
to measure
What are 2 units that scientist use to measure temperature?
To measure temperature, scientists use:KelvinCelsiusFahrenheit.
Why do scientist all over the world use the same type of tools?
Scientist use the same tools because, so their measurements will be the same.
What do scientist use to learn about the properties of stars?
spectroscope
What do a scientist use to study the properties of stars?
Telescope
