Star · K2
HAT-P-18
HAT-P-18 is a main-sequence star of spectral type K2 in the constellation Hercules, 526.4 light-years from the Sun. It is orbited by 1 confirmed exoplanet(s).
| Constellation | Hercules |
|---|---|
| Distance | 526.4 light-years (161.4 pc) |
| Apparent magnitude | magnitude 12.60 |
| Absolute magnitude | magnitude 6.56 |
| Spectral type | K2 |
| Surface temperature | 4,870 K |
| Luminosity | 0.26 L☉ |
| Radius | 0.717 R☉ |
| Mass | 0.77 M☉ |
| Age | 12.4 billion years |
| Metallicity [Fe/H] | 0.10 |
| Right ascension (J2000) | 17h 05m 23.1s |
| Declination (J2000) | +33° 00′ 44″ |
| Space velocity (relative to the Sun) | 30.1 km/s |
In the sky
A telescope is needed to see it: its apparent magnitude is 12.60. Visible from the whole Northern Hemisphere and south to latitude 57° S. North of latitude 57° N it never sets. It stands highest at midnight in June, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around the year 1500. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 9.3 million years.
The Sun seen from there
From a planet around HAT-P-18, the Sun would look like a star of magnitude 10.87, in the direction where our sky has the constellation Columba. It would be invisible to the naked eye.
Planets
- HAT-P-18 b 5.51-day orbit · 10.7 R⊕
Stellar parameters from the NASA Exoplanet Archive; position and brightness from the HYG / AT-HYG catalogue.