It is an exoplanet and the first planet discovered around a Sun like star.
This planet is about half the size of Jupiter and orbits its star in about 4 days.
51 Pegasi b is 50 light years away from earth.
It is 47% less massive but 50% larger than the Jupiter.
It is 11% more massive and 23% larger than our sun.
Hot Jupiter’s were not thought to be possible 20 years ago. But this discovery challenged existing theories of planet formation. Astronomers now believe that large planets may form far from their stars and migrate closer to their stars over millions of years.