How do emission and reflection nebulae differ?(1 point)
Responses
hard line edges
hard line edges
interactions with light
interactions with light
contain remnants of stars
contain remnants of stars
the presence of young stars
The presence of young stars.
Emission and reflection nebulae differ in several ways:
1. Interactions with light: Emission nebulae emit light of their own, usually in the form of specific wavelengths or colors. They are often composed of ionized gas that emits light due to the energy given off by nearby stars or other energetic processes. On the other hand, reflection nebulae do not emit their own light but simply reflect the light of nearby stars. They are made up of dust particles that scatter and reflect the starlight.
2. Hard line edges: Emission nebulae typically have softer and diffuse boundaries without distinct edges. They often appear as glowing and cloudy regions of space. In contrast, reflection nebulae may have sharper and more defined edges due to the scattering of light by dust particles.
3. Contain remnants of stars: Both emission and reflection nebulae can contain remnants of stars, such as stellar remnants, star clusters, or even protostars. These objects can be found within both types of nebulae.
4. The presence of young stars: Emission nebulae are often associated with regions of active star formation. They can contain young, hot stars that emit intense radiation, ionizing the surrounding gas and creating the visible emission. On the other hand, reflection nebulae may also indicate regions of star formation, but their presence may not be as closely tied to the formation of new stars as emission nebulae.
Emission and reflection nebulae differ in terms of their interactions with light and the presence of young stars.
1. Interactions with light:
Emission nebulae emit their own light. They are composed of ionized gas, usually hydrogen, that is energized by nearby hot stars. These stars emit ultraviolet radiation which causes the gas to glow, creating a colorful nebula. The light emitted by an emission nebula is often in the form of specific wavelengths, such as the red light emitted by hydrogen gas.
On the other hand, reflection nebulae do not emit their own light. Instead, they reflect the light of nearby stars. Dust particles within the nebula scatter and reflect the starlight, making the nebula appear blue due to the scattering of shorter-wavelength light. Unlike emission nebulae, reflection nebulae do not produce specific emission lines as they do not have ionized gas.
2. The presence of young stars:
Emission nebulae are often associated with regions of active star formation. The intense UV radiation emitted by young, hot stars within the nebula ionizes the surrounding gas, causing it to emit light. These young stars are typically formed within the same molecular cloud that gives rise to the emission nebula.
In contrast, reflection nebulae do not necessarily indicate regions of active star formation. They can exist in any area where there is enough dust and nearby stars to illuminate the nebula. The presence of young stars within a reflection nebula may vary, as it depends on the proximity of such stars to the nebula.
To determine whether a nebula is an emission or reflection nebula, one can look at the spectrum of the emitted light. Emission nebulae will exhibit characteristic emission lines, while reflection nebulae will not. Additionally, studying the region around the nebula for the presence of young stars can provide further clues.