1. Astronomy 1020 Stellar Astronomy Spring_2016 Day-15

2. Solar Flare

3. Lab This Week Lenses & Telescopes What you need to know: You get to visualize the spectra from various sources. Reading ahead in Chapter 6 will help.

4. Telescopes Telescopes have three functions: 1. Gather light LGP ∝ Area = πR 2 2. Resolve objects Θ = 2.06 X 10 5 ( λ/D) 3. Magnify EXTENDED objects

5.  Focal length: distance between lens and the image (longer = larger image).  Aperture sets the light-collecting power.  Focal length determines the image size.

6. Course Announcements 1 st “Hot Topics in Science”: Coming Soon Topics this semester are: Human Cloning, Environmental Toxicology, & Fracking … includes pizza. Dark Night Observing: Mon. 2/29 & Wed. 3/2 – 7:30pm at the APSU Observatory Exam-2 – Fri. 3/4 Chapters 5 & 6 Smartworks Chapters 5 & 6: Due Fri. 3/4 Spring Break Mar. 5-13 (Sat.-Sun.) APSU Research and Creativity Forum April 15, 2016 Abstracts are due: 4:00pm Fri., March 18 Feb. 29 – Last day to drop with an automatic “W” Apr. 1 – Last day to drop a class with W, F, FA

7.  The wavelengths at which atoms emit and absorb radiation form unique spectral fingerprints for each atom.  They help determine a star’s composition, temperature, and more.

8.  The motion of a light source toward or away from us changes our perception of the wavelength of the waves reaching us.  Doppler effect.

9.  If you know the wavelength of light you are observing as well as the wavelength of light the object would be emitting if it were at rest, you can find the speed of the object using the Doppler effect. MATH TOOLS 5.2

11.  Light from approaching objects is blueshifted; the waves crowd together.  Light from receding objects is redshifted; the waves are spaced farther apart.

12.  The motion of a light source toward or away from us changes our perception of the wavelength of the waves reaching us.  Doppler effect.

13. Lecture Tutorial Doppler Shift: (pg. 75) Work with a partner! Read the instructions and questions carefully. Discuss the concepts and your answers with one another. Take time to understand it now!!!! Come to a consensus answer you both agree on. If you get stuck or are not sure of your answer, ask another group.