HAT-P-3 is 439 light-years from the Sun. The NASA Exoplanet Archive lists 1 planet around this K1 star; the first was found in 2007 by transit (HATNet).
Fly there in 3DHAT-P-3 b goes round its star every 2.90 days, 30 times as often as Mercury goes round the Sun.
HAT-P-3 is one of 2 stars in its system: the other is drawn where the Washington Double Star Catalog measures it on the sky.
| Spectral type | K1 |
| Surface temperature | 5,185 K |
| Mass | 1.06 solar masses |
| Radius | 0.87 solar radii |
| Luminosity | 0.4365 times the Sun |
| Apparent magnitude | 11.856 |
| Age | about 1.6 billion years |
| Distance from the Sun | 438.9 light-years (134.6 parsecs) |
| Position (J2000) | RA 206.0940°, Dec 48.0286° |
| Constellation | Ursa Major |
HAT-P-3 B has no spectral type listed of magnitude 18.5, moving through space with it. In 2015 it was 9.8″ from HAT-P-3, at position angle 170° (Washington Double Star Catalog, 13444+4802 FMR 245): 1,319 AU on the sky at this distance. The true distance can only be larger. Its colour is estimated from its brightness.
| Planet | Year | Orbit | Radius | Mass | Found |
|---|---|---|---|---|---|
| HAT-P-3 b | 2.90 days | 0.0387 AU | 10.536 R⊕ | 206.59 M⊕ | Transit, 2007 |
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.