It is a variable star, unstable in size, that fluctuates erradically in brightness during a period of about 6.4 years. It is interesting to contrast the reddish color of Betelgeuse with Rigel, another supergiant star in Orion. Rigel, about 900 light years away, is located below and to the right of Orion's Belt. It is a blue supergiant, on the other side of the color spectrum of stars from Betelgeuse. The color difference is dramatic when seen with binoculars.
Bluish stars are the hottest.
Reddish stars are the coolest. Between January and June 1996, the planet Venus presents a spectacular sight in the southwestern sky during the first 1 to 2 hours after sunset. Other than the Sun and Moon, Venus is the brightest object in the sky. Because Venus, our next door neighbor in space, is closer to the Sun than Earth is, we see it going through phases that are similar to the Moon's phases. So Venus gets brighter as it comes closer to Earth, even though the part that we see lit up is shrinking.