- Historical event:
- 6 October 1995
- The large planet Bellerophon orbits around the star 51 Pegasi, which is quite similar to our Sun.
On this day in 1995, the first planet outside our solar system that orbits a star similar to our Sun was discovered.
The star in question is 51 Pegasi, which is located some 50.9 light years away from us. The Pegasus constellation is located in the northern sky, in the vicinity of the Andromeda constellation and the zodiac constellations of Aquarius and Pisces.
The mentioned star 51 Pegasi is similar to the Sun being of spectral class G5V (the Sun is G2V), being a yellow star somewhat larger than the Sun. Its surface temperature is around 5,571 K (the Sun being around 5,778 K), and it is between 6.1 and 8.1 billion years old (the Sun is younger, being 4.57 billion years old).
The newly-discovered planet was unofficially named Bellerophon, after the Ancient Greek hero who rode the winged horse named Pegasus. The planet’s official name is 51 Pegasi b. The planet has a mass 150 times greater than Earth, which is around half the mass of Jupiter. The planet’s surface temperature is probably around 1000°C, making it a “hot Jupiter” type planet.
The discovery was published in the Nature magazine, while the planet was discovered by Swiss scientists Michel Mayor and Didier Queloz, who were working at the French OHP observatory (Observatoire de Haute Provence).