Facts about 51 Pegasi
- 09
Official names Helvetios and Dimidium were assigned to the star and its planet in December 2015 through the IAU's NameExoWorlds public contest.
- 08
Located approximately 50.9 light-years from Earth, 51 Pegasi is naked-eye visible in the northern constellation Pegasus as a magnitude 5.49 star.
- 07
Astronomers have observed atmospheric escape from 51 Pegasi b, with hydrogen and helium evaporating into space due to the exoplanet's intense stellar heating and relatively low gravitational escape velocity.
- 06
Doppler spectroscopy observations of 51 Pegasi revealed the exoplanet's presence through periodic shifts in starlight wavelengths of approximately 75 meters per second.
- 05
Around 51 Pegasi, the exoplanet's surface temperature reaches approximately 1,300 Kelvin due to extreme stellar irradiation from its parent star.
- 04
51 Pegasi b has a minimum mass of about 0.46 Jupiter masses, roughly half the mass of Jupiter despite its scorching orbit.
- 03
The host star 51 Pegasi has a mass of approximately 1.11 solar masses and belongs to the G2-type spectral class, similar to our own Sun.
- 02
51 Pegasi b orbits its star every 4.23 days at a distance of 0.0527 astronomical units, roughly nineteen times closer than Earth is to the Sun.
- 01
In 1995, Swiss astronomers Michel Mayor and Didier Queloz discovered the first exoplanet orbiting 51 Pegasi using the radial velocity method.