ASTR Fall Semester Joel E. Tohline, Alumni Professor Office: 247 Nicholson Hall [Slides from Lecture11]

Plot “L vs. T” for 27 Nearest Stars Data drawn from Appendix 4 of the textbook.

L and T appear to be Correlated Nearest Stars

L and T appear to be Correlated A few of the brightest stars in the night sky

Hertzsprung-Russell (H-R) Diagram

Chapter 19: Stellar Evolution: On & after the Main Sequence

Apply the “Age” Concept to Other Stars How long can other stars live? –t age = fMc 2 /L –(t age /10 10 years) = (M/M sun )/(L/L sun )

Apply the “Age” Concept to Other Stars

How does a Star’s Structure Change as it Ages (Evolves)?

Open Cluster: NGC 290

Hertzsprung-Russell (H-R) Diagram

Pleiades Star Cluster (age approximately 50 million years) Figure 18-19

Figure 19-9 Post-main-sequence Evolutionary Tracks:

H-R Diagram for Open Clusters Figure 19-14

Figure 19-11

Globular Cluster M10 Figure 19-12

Globular Cluster M55

Globular Cluster M10 Figure 19-12

Chapter 18: The Birth of Stars

Dust in Spiral Galaxies Figure 18-8

A Dark Nebula in Our Galaxy Figure 18-4

Figure Pre-main-sequence Evolutionary Tracks:

Figure NGC 2264: A Very Young Cluster

Figure 19-10