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Astronomy 1020
Stellar Astronomy
Spring_2016
Day-12
Course Announcements
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1st Quarter observing night: TONIGHT @ 7:30pm
READ through the “Format for the Report” BEFORE
you come.
N
32
Mean
68.5
Std. Dev.
13.57
Median
70.4
Mode
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Min.
45.6
Max.
100
Curve
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Course Announcements
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Colloquium on Friday, Feb. 19. @2:30pm B310
Dr. David James, Cerro-Tololo InterAmerican Obs.
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Open Clusters, Stellar Evolution and Calibrating the Ages
of Stars: Blanco 1
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Galactic open clusters are laboratories, provided by nature, for
us to study stellar evolution. Using 1m-, 4m- and 8m-class
telescopes, I will show how spectroscopic and photometric
observations of solar-type stars in open clusters allow us to
establish a stellar chronometer, and create an age-ranking
system for an ensemble of nearby, well-studied clusters. With
the aid of new observations of Blanco 1, an high-Galactic
latitude, Pleiades-age cluster, I will show how deriving stellar
age must be based upon very high quality observational data
and a diverse range of stellar models.
Course Announcements
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1st “Hot Topics in Science”: Tues. 2/23 6-8pm E106B
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Topics this semester are: Human Cloning, Environmental
Toxicology, & Fracking … includes pizza.
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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.)
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APSU Research and Creativity Forum April 15, 2016
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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
The Origin and Nature of Light
Lab This Week
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The Spectrometer
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What you need to know:
You get to visualize the spectra from various
sources.
Reading ahead in Chapter 5 will help.
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Lab This Week
 The Spectrometer
 Almost all
knowledge of the
universe beyond
Earth comes from
light.
 Light can tell us
about objects in
space: temperature,
composition,
speeds, and more.
What Light Can Tell Us.
 Photometry – Study of Brightness:
 Luminosity, Est. of Distance, Rough Temp. of Star
 Spectroscopy – Study of the EM Spectrum:
 Composition, Radial Velocity, Temp., Surface-gravity
 Mass for compact objects
 Astrometry – Study of Positions:
 Tangential Motion, Distance
 Polarimetry – Study of Polarization of Light:
 Magnetic Field
Spectrum of the Sun
But, what is light?
 Newton, Remember Newton? He did more than just
calculus and mechanics.
 In the 17th Century, Isaac Newton argued that light was
composed of little particles while Christian Huygens
suggested that light travels in the form of waves.
 In the 19th and 20th Century Maxwell, Young, Einstein and
others were able to show that Light behaves both like a
particle and a wave depending on how you observe it.
Particle Nature
Thomas Young’s interference experiment
Wave Nature