PH1600: Introductory AstronomyLecture 14: Stars: Single and Binary

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PH1600: Introductory AstronomyLecture 14: Star: Single and BinaryStudy: Chapter 11 in The Cosmos book Next Lecture: Star Clusters

School: Michigan Technological UniversityProfessor: Robert Nemiroff

Book: The Cosmos by Pasachoff & FilippenkoOnline Course WebCT pages:

http://courses.mtu.edu/

This class can be taken online ONLY, class attendance is not required!

You are responsible for…

Reading the book One chapter per “quiz period” Anything from that chapter can appear on

quizzes or tests, even if I never mention them during my lecture(s)

This quiz period covers Chapter 11 APODs posted during the semester

APOD review every week during lecture Completing the Quizzes

Chapter 1, 2, 4, 6, 7, 8, &10 quizzes already due

Chapter 11 quiz due next See WebCT at http://courses.mtu.edu/ for

details

Stars: Distant Suns

Henrietta Leavitt Calibrates the StarsCredit: AAVSO

APOD: 2000 September 3

Stellar Spectral Types: OBAFGKMCredit & Copyright: KPNO 0.9-m Telescope, AURA, NOAO, NSF APOD: 2004 April 18

http://upload.wikimedia.org/wikipedia/en/4/44/HRDiagram.gif

http://abyss.uoregon.edu/~js/ast122/lectures/lec11.html

http://abyss.uoregon.edu/~js/ast122/lectures/lec11.html

http://abyss.uoregon.edu/~js/ast122/lectures/lec11.html

Orion Star ColorsCredit and Copyright: David Malin

APOD: 1998 August 29

Famous Stars

Sun Polaris

North star Sirius Betelgeuse Alpha Centauri

Proxima Centauri

Polaris: The North StarCredit & Copyright: Wally Pacholka APOD: 1999 October 6

Sirius: The Brightest Star in the NightCredit & Copyright: Juan Carlos Casado APOD: 2000 June 11

X-Rays From Sirius BCredit: NASA/ CXC/ SAO APOD: 2000 October 6

Resolving MiraCredit: M. Karovska (Harvard-Smithsonian CfA) et al., FOC, ESA, NASA APOD: 2001 January 21

A Giant Starspot on HD 12545Credit & Copyright: K. Strassmeier (U. Wien), Coude Feed Telescope, AURA, NOAO, NSF APOD: 2003 November 2

Betelgeuse, Betelgeuse, BetelgeuseCredit: A. Dupree (CfA), R. Gilliland (STScI), NASA

APOD: 1999 June 5

Simulated Supergiant StarCredit: B. Freytag, (U. Uppsala)

APOD: 2000 December 22

Why Stars TwinkleCredit: Applied Optics Group (Imperial College), Herschel 4.2-m Telescope APOD: 2000 July 25

Inverse Square Law of Brightness

http://en.wikipedia.org/wiki/Image:InverseSquareLaw.png

Example

Stars A and B are identical. Star B is at twice the distance of star A. How much brighter does star A appear than star B?

Use inverse square law: lA =k/rA2

Also, lB=k/rB2. Therefore lA/lB=(rB/rA)2 =

22 = 4.

Proxima Centauri: The Closest StarCredit & Copyright: David Malin, UK Schmidt Telescope, DSS, AAO APOD: 2002 July 15

Alpha Centauri: The Closest Star SystemCredit: 1-Meter Schmidt Telescope, ESO APOD: 2003 March 23

Binary Stars

Visual Binaries Can see two or more

Spectroscopic binaries Doppler color changes

Eclipsing Binaries Dark times

Astrometric Binaries Wobble

Albireo: A Bright and Beautiful DoubleCredit & Copyright: Richard Yandrick (Cosmicimage.com)APOD: 2005 August 30

http://en.wikipedia.org/wiki/Image:Orbit5.gif

The Big Dipper ClusterCredit & Copyright: Noel Carboni APOD: 2006 March 17

Mizar Binary StarCredit: J. Benson et al., NPOI Group, USNO, NRL

APOD: 1997 February 19

http://csep10.phys.utk.edu/astr162/lect/binaries/spectroscopic.html

http://en.wikipedia.org/wiki/Eclipsing_binary

Mira: The Wonderful StarIllustration Credit: M.Weiss(CXC)APOD: 2005 May 5

NGC 3132: The Eight Burst NebulaCredit: Hubble Heritage Team (AURA/STScI /NASA)APOD: 2003 September 13

An Intermediate Polar Binary SystemIllustration Credit & Copyright: Mark Garlick (Space-art)APOD: 2003 November 10