Sunspots are dark because they are much cooler than the surrounding portions of the sun, according to Cool Cosmos, a joint project by the National Aeronautic and Space Administration’s Jet Propulsion Laboratory and California Institute of Technology’s Infrared Processing and Analyses Center. These sunspots usually have temperatures of approximately 6,300 degrees Fahrenheit, while the surrounding portions of the sun are approximately 10,000 degrees Fahrenheit.Know More
As explained on SpaceWeather.com, scientists count and catalog these planet-sized cool spots. According to the Marshall Space Flight Center, the abundance of sunspots varies in time. During the late 17th century and early 18th century, sunspot activity was very low. Concurrently, with this reduction in solar spot frequency, the Earth’s temperature dropped significantly. This period is often referred to as the “little ice age,” as many rivers and snowfields remained frozen longer than normal. There is some evidence that similar cool periods occurred in the more distant past as well.
According to Windows to the Universe from the National Earth Science Teachers Association, the sun’s magnetic field causes the sunspots. Once formed, the sunspots may last as briefly as a few hours or as long as a few months. Sunspots typically fluctuate through an 11-year cycle. Even though sunspots appear dark against the surface of the sun, the areas are still almost as bright as the full moon, and if moved away from the sun, they would be luminous.Learn more about Stellar Astronomy
The largest identified star in the known universe is VY Canis Majoris, a hypergiant of the constellation Canis Major, calculated to be more than 1,540 times larger than the sun. YV Canis Majoris is situated 5,000 light years away from earth and is probably far from the largest star in the galaxy.Full Answer >
Scientists believe the sun has enough hydrogen to burn for another 5 billion years, according to Space.com. It is approximately 4.6 billion years old, so the sun has used up about half of its hydrogen since it was formed.Full Answer >
Ceres is about 258 million miles from the sun, as stated by NASA. Its orbit around the sun crosses between Mars and Jupiter.Full Answer >
The two types of stars that end with supernovae are white dwarfs and massive stars that are at least eight times the mass of the sun. Each of these types of stars undergoes a thermonuclear reaction at the end of its life.Full Answer >