Astronomy Star Type Calculator is an iPhone application designed to calculate the precise spectral type of a main sequence star based on its surface temperature. This educational app allows users to explore the different classes of stars, ranging from M through O, including newer star types like Y, K, and L.

With this app, users can enter a surface temperature ranging from 250K to 60,000K, and the results will update in real time as the temperature is edited. The app also provides pictures of example stars from each spectral class, allowing users to visually understand the differences between the classes.

In addition, Astronomy Star Type Calculator offers information about the MK System, which defines each star class. Users can learn about the characteristics and properties of each class, enhancing their knowledge of stellar classification.

For a comprehensive overview, the app includes a graph that shows the distribution of star classes versus luminosity. This visual representation helps users understand the relationship between spectral types and the luminosity of stars.

Astronomy Star Type Calculator is a valuable tool for astronomers, students, and enthusiasts who want to deepen their understanding of stellar classification. With its user-friendly interface and real-time calculations, this app provides an accessible way to explore the vast variety of main sequence stars.