Aurora effect is known as the aurora borealis or the northern lights. The former term was coined by Galileo in 1619, from the Roman goddess of the dawn and the Greek name for the north wind. The southern counterpart, the aurora australis or the southern lights, has features almost identical to the aurora borealis and changes simultaneously with changes in the northern auroral zone. The Aurora Australis is visible from high southern latitudes in Antarctica, Chile, Argentina, New Zealand, and Australia. A geomagnetic storm causes the auroral ovals (north and south) to expand, and bring the aurora to lower latitudes. The
Corona Borealis respectively. Chinese astronomers deemed nine stars to make up the asterism, adding Pi and Rho Coronae Borealis. Within the constellation's borders, there are 37 stars brighter than or equal to apparent magnitude 6.5. Alpha Coronae Borealis (officially named Alphecca by the IAU, but sometimes also known as Gemma) appears as a blue-white star of magnitude 2.2. In fact, it is an Algol-type eclipsing binary that varies by 0.1 magnitude with a period of 17.4 days. The primary is a white main-sequence star of spectral type A0V that is 2.91 times the mass of the Sun () and 57 times as