GEOL3045: Planetary Geology Lysa Chizmadia The Sun & Ulysses Lysa Chizmadia The Sun & Ulysses

Introduction  Mass = x kg  99.8% of solar system  Diameter = 1.39 x 10 6 km  Temperature  5800 (sfc) x 10 7 K (core)  Class G star (G2V)  Population I star  metallicity high  Galactic velocity  2.17 x 10 5 m/s  Galactic period  x 10 8 a  Mass = x kg  99.8% of solar system  Diameter = 1.39 x 10 6 km  Temperature  5800 (sfc) x 10 7 K (core)  Class G star (G2V)  Population I star  metallicity high  Galactic velocity  2.17 x 10 5 m/s  Galactic period  x 10 8 a Image from: asdictionary.blogspot.com Image from:

Spectroscopy  Pure white light yields continuous spectra, like a rainbow  Individual elements produce line spectra like fingerprints  Pure white light yields continuous spectra, like a rainbow  Individual elements produce line spectra like fingerprints

Stellar Spectroscopy  Hot objects yields continuous spectra  Like a rainbow  Atoms emit light of specific wavelengths  Line spectrum  Individual to each atom (fingerprint)  Atoms in front of hot object, absorb light at their fingerprint wavelengths  Absorption spectra  Hot objects yields continuous spectra  Like a rainbow  Atoms emit light of specific wavelengths  Line spectrum  Individual to each atom (fingerprint)  Atoms in front of hot object, absorb light at their fingerprint wavelengths  Absorption spectra Images from:

Sun’s Spectra  Sun is relatively cool (T=5,500K)  For comparison, Vega (T=10,000K)  Sun is relatively cool (T=5,500K)  For comparison, Vega (T=10,000K) Images from:

Sun Spots  Cooler parts of Sun’s surface  3800 K vs K  22 year cycles  Change in magnetic poles  Differential rotation  Equator = 25.4 days  Poles = 36 d  Layers:  Cooler parts of Sun’s surface  3800 K vs K  22 year cycles  Change in magnetic poles  Differential rotation  Equator = 25.4 days  Poles = 36 d  Layers: Image from: Image from: /nineplanets/sol.html Image from: nmp.nasa.gov/ st5/SCIENCE/sun.html

Aurora  Borealis = north  Australis = south  Interaction of solar wind with Earth’s magnetic field  Particles have E from keV  Collisions with oxygen  Green and red emissions  Collisions with nitrogen  Low level red and very high blue/violet  Borealis = north  Australis = south  Interaction of solar wind with Earth’s magnetic field  Particles have E from keV  Collisions with oxygen  Green and red emissions  Collisions with nitrogen  Low level red and very high blue/violet Images from: Image from:

Ulysses Mission  Launched by NASA in 1990  Gravity boosts by Jupiter in 1992  Sling-shotted out of ecliptic  Perihelion = 5.2 AU  Aphelion = 1.5 AU  Launched by NASA in 1990  Gravity boosts by Jupiter in 1992  Sling-shotted out of ecliptic  Perihelion = 5.2 AU  Aphelion = 1.5 AU Image from:

Ulysses (con’t)  New solar cycle starting  Will be able to study sun spot cycle  How does a change in magnetic field effect solar wind, galactic cosmic rays & us on Earth?  Mission highlights:  Observed 4 large coronal mass ejections merge into large interplanetary shock wave  Feb 2005  Discovered e- jets from Jupiter  Feb 2006  Near pass with comet C/2006 P1 McNaught  Feb 2007  New solar cycle starting  Will be able to study sun spot cycle  How does a change in magnetic field effect solar wind, galactic cosmic rays & us on Earth?  Mission highlights:  Observed 4 large coronal mass ejections merge into large interplanetary shock wave  Feb 2005  Discovered e- jets from Jupiter  Feb 2006  Near pass with comet C/2006 P1 McNaught  Feb 2007 Image from:

Summary  Sun is main sequence star  In mid-life  Population I star  High metallicity  Ulysses mission  Launched in 1990  Should reveal how changes in solar magnetic field effect solar wind, background radiation & current technology  Sun is main sequence star  In mid-life  Population I star  High metallicity  Ulysses mission  Launched in 1990  Should reveal how changes in solar magnetic field effect solar wind, background radiation & current technology