The cool and hot spots within the photosphere of the sun are called:

Correct option is D

1. Sunspots:
· Sunspots are areas on the photosphere of the Sun that appear darker because they are cooler than the surrounding regions.
· These are caused by the Sun's magnetic field inhibiting convection, resulting in reduced surface temperature in these spots.
· Sunspots are typically surrounded by brighter, hotter regions known as faculae.
· They serve as indicators of solar activity, including solar flares and coronal mass ejections.
2. Albedo (Option 1):
· Albedo refers to the reflectivity of a surface, not specific to the Sun or photosphere.
3. Corona (Option 2):
· The corona is the outermost layer of the Sun's atmosphere, not the photosphere. It is visible during solar eclipses and is much hotter than the photosphere.
4. Faculae (Option 3):
· Faculae are the brighter, hotter regions around sunspots, but they are not the "cool spots" themselves.
Thus, the correct answer is (4) Sunspots.
Information Booster: 1. Photosphere Characteristics:
· The photosphere is the visible surface of the Sun.
· Temperature ranges from 4,500 to 6,000 K.
· Features include granules, sunspots, and faculae.
2. Sunspot Cycle:
· Sunspots follow an 11-year solar cycle, with periods of high and low activity.
· Increased sunspot activity is associated with higher solar radiation and geomagnetic storms on Earth.
3. Faculae vs Sunspots:
· Sunspots are cooler and darker.
· Faculae are brighter and hotter, enhancing solar radiation.
4. Albedo Relevance:
· Albedo is critical in understanding Earth's energy balance but is unrelated to sunspots
Additional Knowledge: · Corona (Option 2):
· It is primarily studied during solar eclipses or with coronagraphs.
· Temperatures in the corona exceed 1 million K.
· Faculae (Option 3):
· Best observed near the Sun’s limb.
· They contribute to the Sun’s luminosity, even during periods of low sunspot activity.
· Impact of Sunspots on Earth:
· Solar flares and coronal mass ejections associated with sunspots can disrupt satellite communications, GPS systems, and power grids on Earth.