HAT-P-2 is 417 light-years from the Sun. The NASA Exoplanet Archive lists 2 planets around this F8 star; the first was found in 2007 by transit (HATNet).
Fly there in 3DHAT-P-2 b goes round its star every 5.63 days, 16 times as often as Mercury goes round the Sun.
Where the archive gives only a period or only an orbit size, the other is worked out from Kepler’s third law with the star’s mass.
| Spectral type | F8 |
| Surface temperature | 6,380 K |
| Mass | 1.33 solar masses |
| Radius | 1.39 solar radii |
| Luminosity | 3.388 times the Sun |
| Apparent magnitude | 8.72 |
| Age | about 1.44 billion years |
| Distance from the Sun | 416.7 light-years (127.8 parsecs) |
| Position (J2000) | RA 245.1514°, Dec 41.0480° |
| Constellation | Hercules |
| Planet | Year | Orbit | Radius | Mass | Found |
|---|---|---|---|---|---|
| HAT-P-2 b | 5.63 days | 0.0681 AU | 10.66 R⊕ | 2866.8 M⊕ | Transit, 2007 |
| HAT-P-2 c | 23.3 years | 8.964 AU from Kepler’s law | 12.4 R⊕ estimated | 3400.8 M⊕ | Radial Velocity, 2023 |
Values are the NASA Exoplanet Archive’s composite parameters. A radius marked estimated comes from a mass–radius relation; a mass marked minimum is M sin i. Planet sizes and colours in the 3D view are renderings: none of these worlds has been photographed as more than a point of light.
For a star of 6,380 K, 3.4 times as bright as the Sun, the habitable zone, where starlight could keep water liquid on a rocky surface, runs from about 1.69 to 2.94 AU. None of its known planets orbits inside it. The zone says how much starlight arrives, not whether a planet has water or air. The edges follow Kopparapu et al. (2014), as the 3D view draws them.
The light you see left 417 years ago, around 1610.