The Dynamic SunLecture 10

The Dynamic Sun

• Solar rotation with sunspots http://science.nasa.gov/ssl/pad/solar/sunturn.htm

• CME eruption http://science.nasa.gov/ssl/pad/solar/cmes.htm

• Rotating Sun in X-rays http://www.solarviews.com/cap/sun/sxt.htm

• Dynamics of coronal loops http://science.nasa.gov/ssl/pad/solar/loops.htm

Solar Events of Last October and November

“The Day the Sun Went Wild”: Largest Flares Since the Space Age

http://sohowww.nascom.nasa.gov/

The Flare of November 4, 2003

If directed at Earth, would have

damaged system of geosynchronous

satellites. Radiation would

have killed astronauts in interplanetary

space

The Stars“e quindi uscimmo a riveder le stelle”

Last words of Dante’s Inferno

The Stars are other Suns

Or…the Sun is the closest star

Basic Questions about Stars

• How far away are they?

• How hot are they?

• How massive are they

• What are they made of?

• Do they have planets too?

16 Cygni

Most Basic Method of Stellar Distance Determination

Trigonometric parallax: an ordinary surveying technique

Figure 16.1 of textbook

DEMO

Next time:

• How far away are the stars (compared to solar system distances)?

• What units do we use to describe their distances?