I) the Sun A) Properties of the Sun
The Sun is the largest object in our solar system, in both diameter and mass, it’d take about 109 Earth’s or 10 Jupiter’s to fill the Sun, and it is about 330,000 times as massive as Earth or 1048 the mass of Jupiter, the Sun makes up 99% of the mass of our Solar System.
a) Table 29.1 shows us the relative properties of the sun compared to Earth and Jupiter. B) The Sun’s Atmosphere
The outer regions of the Sun are organized into layers, like that of a planetary atmosphere separated into different levels. 1) Photosphere
The Photosphere is approximately 400 km thick and has an average temperature of 5800 K.
a) the Photosphere is the visible surface of the Sun, it is also the inner most layer of its atmosphere it is the visible layer because the outer levels are much dimmer than the photosphere.
b) Figure 29.1 shows us the photosphere, or the visible surface of the sun. 2) Chromosphere
Outside of the photosphere is the chromosphere, it’s about 2500 km thick and is nearly 30,000K. a) the Chromosphere is located outside the photosphere and is usually red due to its strongest emission being in a single band in the red wavelength, it is only visible when the sun is eclipsed or when a special lens is equipped on a telescope.
b) Figure 29.1 shows us the chromosphere and just how red it is, and how it looks through a telescope with the special lens equipped. 3) Corona
The corona is the outer most layer of the sun and can only be seen in special circumstances.
a) The Corona extends several million kilometers from the outside edge of the chromosphere and has temps ranging from 1 million to 2 million K, it has very low gas density which explains why it is so dim, it can only be seen when special instruments block the photosphere or the moon during an eclipse.
b) Figure 29.2 shows us that the hottest and outermost layer, the corona can only be seen when the disk of the sun is blocked like in a solar eclipse. 4) Solar Wind
The corona of the Sun has gas that flows outward from it at high speeds and forms the Solar Wind.
a) Solar Wind is a wind of charged particles, called ions, and flows outward to all planets, showering all the planets in charged particles.
b) Figure 29.3 shows us the Aurora, a long strip of light caused by the ions and gases in our atmosphere mixing together they are generally seen in the polar regions. C) Solar Activity
There is a process in which features of the Sun changes, it is called Solar Activity, examples include fountains and gas loops, and this structure is driven by magnetic fields. 1) The Sun’s Magnetic Field and Sunspots
The Sun’s magnetic field causes disturbances in its atmosphere causing new features to appear, the most obvious feature are sunspots.
a) Sunspots are dark spots on the Sun’s surface and they are bright but appear darker than their surrounding areas because they are much cooler. b) Figure 29.4 shows us sunspots on the surface if the photosphere. 2) Solar Activity Cycle
Having observed that the number of sunspots changes over time on a regular basis, astronomers have concluded that it reaches a maximum every 11.2 years and when this happens, the Sun’s magnetic poles reverse starting the 11.2 year process again and reverses one more time completing the solar activity cycle.
3) Other Solar Features
Other solar features include coronal holes, solar flares, and prominences. a) Figure 29.5 shows us what coronal holes, solar flares, and solar prominences look like. b) Solar Flares are violent eruptions of particles and radiation from the surface of the Sun. c) Prominences are arcs of gas ejected from the chromosphere or are gases that condense in the inner corona and rain back down to the surface.
D) The Solar Interior
Within the solar interior two things occur: Fusion and Fission. a) Fusion is the combination of lightweight, atomic nuclei into heavier nuclei, for example