Lerna
HAT-P-42
📋 A written introduction is coming — for now this page shows official values only.
Star
- Apparent magnitude
- 12 mag
- Distance from Earth
- 405.238 pc (≈ 1,321.7 light-years)
- Surface temperature
- 5,743 K
- Right ascension
- 135.3444°
- Declination
- 6.0972°
- Designation
- HAT-P-42
- IAU name adopted
- 2019-12-17
- Name language
- Greek
- Name origin (IAU)
- Lerna was the name of a lake in the eastern Peloponnese, where the Lernaean Hydra, an immortal mythical nine-headed beast lived. The star lies in the constellation of Hydra.
Source:IAU Working Group on Star Names · checked 2026-11-02 ↗NASA Exoplanet Archive (Caltech/IPAC) · checked 2026-11-03 ↗
Related
Constellation
Planets
In everyday life
- Light from this object takes about 1,322 years to reach Earth — the light you see tonight left around AD 704 (official distance ÷ speed of light).
- At magnitude 12 it is fainter than the naked-eye limit (about 6) — you need binoculars or a telescope.
- Declination 6.1° — it rises above the horizon in Seoul (37.6° N), so it is visible from Korea in the right season.
Worked out from this object's official values.