Photo Credit: NASA, HST, W. Freedman (CIW), R. Kennicutt (U. Arizona), J. Mould (ANU) |
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Code Number: 8B30.40
Demo Title: Variable Stars - Cepheid Variable Stars
Condition: Good
Area of Study: Stellar Astronomy
Equipment:
Power Supply, Tap Switch, 6 to 8 Volt Light Bulb, 90,000 mf Capacitors, Vernier Interface and Light Sensor, Computer.
Procedure:
Connect the power supply, light bulb, and tap switch in series, and set the power supply to 4 volts DC. Place the capacitors in parallel with the light bulb. When you press the tap switch, the luminosity will increase quickly but when you then release the tap switch the luminosity will decrease much more slowly. This is a fair representation of actual Cepheid Variable light curves.
References:
- Jay M. Pasachoff and Jason W. Mativi, "Demonstrating the Cosmic Distance Ladder with Cepheids", TPT, Vol. 58, #1, Jan. 2020, p. 6.
- George S. Mumford, "Scatter", TPT, Vol. 32, #3, Mar. 1994, p. 133.
- John R. Percy, "Variable Stars", TPT, Vol. 31, #9, Dec. 1993, p. 541.
- David L. DuPuy, "Using a Classroom Variable Star in Introductory Astronomy Courses", AJP, Vol. 54, #11, Nov. 1986, p. 976.
- J. B. Rafert and R. C. Nicklin, "Observing Variable Stars Indoors with a Microcomputer and Phototransistor", AJP, Vol. 51, #7, July 1983, p. 668.
- Terry R. Flesch, "Observing Simulated Cepheid Variable Stars in an Introductory Astronomy Lab", AJP, Vol. 47, #3, March 1979, p. 232.
- W. E. Hughes, "Variable Star Simulator", AJP, Vol. 44, #12, Dec. 1976, p. 1227.
- Steven K. Blau, "A Standard Candle Slowly Burns Down", Physics Today, Vol. 64, #3, Mar. 2011, p. 22.
- Dorota M. Skowron, Jan Skowron, Przemek Mróz, Andrzej Udalski, Paweł Pietrukowicz, Igor Soszyński, Michał K. Szymański, Radosław Poleski, Szymon Kozłowski, Krzysztof Ulaczyk, Krzysztof Rybicki, and Patryk Iwanek, "A Three-Dimensional Map of the Milky Way using Classical Cepheid Variable Stars", Science, Vol. 365, #6452, Aug. 2019, p. 478.