Astronomy - Chapter 15

Flashcards covering vocabulary related to the Sun, its features, and solar activity.

Solar Flare

A sudden flash of increased brightness on the Sun, usually observed near sunspots and associated with other active phenomena.

Coronal Mass Ejection (CME)

A significant release of plasma and magnetic field from the solar corona.

Photosphere

The visible surface of the Sun.

Sunspots

Temporary phenomena on the Sun's photosphere that appear as dark spots compared to surrounding regions.

Granulation

The grainy appearance of the Sun's photosphere, caused by convection currents.

Chromosphere

A layer of the solar atmosphere above the photosphere and below the corona.

Corona

The outermost layer of the Sun's atmosphere.

Solar Atmosphere

The outer layers of the Sun, including the photosphere, chromosphere, and corona.

Transition Region

A thin layer in the solar atmosphere between the chromosphere and the corona, where the temperature increases rapidly.

Spicules

Jets of gas that shoot up from the Sun's surface.

Coronagraph

An instrument that blocks the direct light from a star so that nearby objects can be seen.

Coronal Hole

Regions in the Sun's corona that are cooler and less dense than surrounding areas, and from which solar wind emanates.

Solar Wind

A stream of charged particles released from the upper atmosphere of the Sun.

Aurora

A natural light display in the sky, predominantly seen in the high-latitude regions (around the Arctic and Antarctic).

Zeeman Effect

The splitting of spectral lines in the presence of a magnetic field.

Magnetogram

An image showing the magnetic polarity of sunspots.

Solar Cycle

The approximately 11-year cycle of solar activity.

Plages

Bright cloud-like regions in the chromosphere of the Sun, typically found near sunspots.

Prominences

Large, bright, gaseous feature extending outward from the Sun's surface.

Active Regions

Areas on the Sun with strong magnetic fields, often the site of sunspots, flares, and prominences.

Little Maunder Minimum

A period of low sunspot activity during the 17th century.

Solar Dynamics Observatory (SDO)

A NASA mission to study the Sun's influence on Earth and near-Earth space.

Solar and Heliospheric Observatory (SOHO)

A joint ESA/NASA mission to study the Sun, from its deep core to the outer corona and the solar wind.

Space Weather

Conditions on the Sun, in the solar wind, magnetosphere, ionosphere and thermosphere that can influence the performance and reliability of spaceborne and ground-based technological systems and can endanger human life or health.

Eruptive Prominence

A prominence that rapidly changes its structure, often associated with coronal mass ejections.