Hertzspring Russel Diagram

  

Hertzspring Russel Diagram

Trey Riley

Missouri State University

Procedure: 

          All data was gathered from a provided excel data sheet of Orion Stars and Nearby Stars. Data was to be synthesized from the data sheet into a H-R diagram. Once this process was done, many questions concerning the data were posed, and then answered by data given either within the graph of Orion Stars and Nearby Stars, or by handouts given with the lab instructions.

Results and Discussion:

A)    Orion stars are very similar to the H-R Diagram provided. A majority of stars lie on the main sequence. Some differences include the presence of supergiants, giants, and white dwarfs. This H-R Diagram is very normal, showing the age of Orion to be a relatively new nebula, in millions of years since most extremely large and hot stars still lie on the main sequence.

           1 – The luminosities and surface temperatures of the Orion Stars are all extremely luminous and hot on average. A majority of the stars on this H-R Diagram are O, B, and A stars. These stars are all have hot surface temperatures, large radii, and are increasingly blue with temperature. These stars are multiple times more massive than our Sun.

            2 – The luminosities of these stars compared with that of the Sun are hundreds to thousands of times brighter. Therefore the temperatures of these stars are four to five times as hot as the surface of our Sun.

            3 -

Hottest Star #	Largest Star #	Most Luminous Star
8 (Theta 1A)	1 (Alpha)	2 (Beta)

            4 -

Surface Temperature #16 (Mu Ori)	Radius #28 (Phi 2 Ori)
9500K	1000R☉

5 – Orion’s stars are a distance away. I would imagine they are hundreds to thousands of light years away due to their magnitudes from the data table.

B)

            6 – The surface temperatures and luminosities of the nearest stars are on average very dim and consist of cooler stars than that of the Orion stars. Aside from the two stars off the main sequence, all stars lie from an A star to a M star. The majority of stars are G, K, and M stars, which are all yellow to red as absolute magnitude increases, smaller in radius as absolute magnitude increases, and become increasingly dim and cool as absolute magnitude increases.

            7 – The Sun’s surface temperature and luminosity fit in on the main sequence of this H-R Diagram. The Sun is almost in the middle of the stars on this H-R Diagram. The Sun is one of the most luminous and hottest out of this data set.

8 -

Lowest Surface Temperature #	Smallest Radius #	Smallest Luminosity #
6 (Wolf 359)	9 (Sirius B)	6 (Wolf 359)

9 – Some of these stars can easily be seen, and are the brightest in our night sky due to the close proximity of them. A majority of these stars are very dim and small, with little luminosity. With a telescope that has enough light gathering power, all of these stars could be seen.

10 – The nearest stars would be far more common than Orion’s stars. Almost all of Orion’s stars are new stars that are extremely hot and luminous. After time though, these stars die leaving behind smaller and less dim stars. Since our universe has been around for 13.6 billion years, smaller and less luminous stars should be far more common.

11 – The point of this lab was to see real data and apply to H-R diagrams that we made ourselves, and then be able to interpret the data we gathered from the lab.

12 – Orion is a young star system, our nearest stars are all relatively small and dim compared to our Sun, and our nearest stars are almost all still on the main sequence.

Conclusion:

            H-R Diagrams are useful when evaluating star clusters. They can tell Magnitude, temperature in Kelvin, luminosity, spectral class, and solar radius. When evaluating Orion stars, they were found to be new, mainly O, B, and A stars that are all luminous and hot with solar radius 1-10 times that of our Sun. The nearest stars were found to be mainly old, G, K, and M stars that are dim and cool with solar radius .01 to 1 times that of our Sun. Since the nearest stars are close, most can be easily seen. Orion stars are anywhere from 250 to 1250 light years away, resulting in only the brightest stars being able to be seen.