The Milky Way Galaxy is estimated to contain between 100 billion and 400 billion stars. However, the exact number is difficult to determine due to the vastness and complexity of the galaxy.

One way astronomers estimate the number of stars in the Milky Way is by using statistical methods. They observe a small region of the galaxy and count the number of stars within that region. Then, they extrapolate this data to estimate the total number of stars in the entire galaxy. This method is similar to estimating the population of a city by counting the number of people in a small sample area and then multiplying it by the total area of the city.

Another way to estimate the number of stars in the Milky Way is by studying the galaxy's mass and luminosity. By measuring the total mass of the galaxy and the average mass of individual stars, scientists can estimate the number of stars. Similarly, by measuring the total luminosity (brightness) of the galaxy and the average luminosity of individual stars, they can also estimate the number of stars.

However, it is important to note that these estimates are subject to uncertainties and can vary depending on the assumptions and methods used. Additionally, the Milky Way is a dynamic and evolving galaxy, with stars being born and dying over time, which further complicates the estimation process.

Overall, the estimated range of 100 billion to 400 billion stars in the Milky Way is based on various observational and theoretical studies. It is worth mentioning that these estimates may change as our understanding of the galaxy improves and new techniques are developed.

References:

• NASA: How Many Stars Are in the Milky Way? (https://www.nasa.gov/mission_pages/hubble/science/milky-way-stars.html)
• National Geographic: How Many Stars Are in the Milky Way? (https://www.nationalgeographic.com/news/2015/1/150111-astronomy-astrophysics-milky-way-space-ngbooktalk/)