L 98-59
Star
L 98-59 - a red dwarf 34.6 light-years away in Volans, host to a remarkable family of FIVE planets. The three innermost transit the star, so their sizes and densities are measured - among them one of the smallest exoplanets ever weighed, at about half Earth's mass - and the system is a leading target for the James Webb Space Telescope's search for atmospheres.
Open in 3D viewSee L 98-59 in the live, interactive 3D map
Key facts
Mass
5.81 × 10²⁹ kg
0.292 M☉
Radius
219,493 km
32% of the Sun's radius
Surface temperature
3,415 K (3,142 °C)
Luminosity
4.67 × 10²⁴ W
Spectral type
M3V (red dwarf)
Science
Physical
- Mass
- 5.81 × 10²⁹ kg · 0.292 M☉
- Radius
- 219,493 km · 32% of the Sun's radius
- Density
- 13,125 kg/m³ · 13× water
- Computed from mass and radius
- Spectral type
- M3V (red dwarf)
Motion through space
- Proper motion
- 0.353 arcseconds per year · its drift across our sky
- SIMBAD — 2020yCat.1350....0G, 2020AJ....160...83S
- Radial velocity
- -5.9 km/s · approaching the Sun
- SIMBAD — 2020yCat.1350....0G, 2020AJ....160...83S
- Speed across our line of sight
- 17.8 km/s
- Computed from proper motion and parallax
- Speed through space, relative to the Sun
- 18.7 km/s
- Computed from proper motion, parallax and radial velocity
Rotation
- Note
- A quiet red dwarf whose three inner planets transit, enabling precise sizes, masses and atmospheric study.
Composition
- By mass
- A hydrogen/helium red dwarf about 0.29 solar mass and ~1.2% of the Sun's light, 34.6 light-years away in Volans. Its three inner planets transit, making the system one of the best-characterised — and a leading target for the James Webb Space Telescope's search for atmospheres.
Temperature
- Surface
- 3,415 K (3,142 °C)
Radiation & temperature
- Luminosity
- 4.67 × 10²⁴ W · 0.0122 L☉
- Surface temperature
- 3,415 K (3,142 °C)
- Peak wavelength
- 849 nm · near-infrared (mostly invisible to the eye)
- Computed (Wien's law) from the surface temperature
Discovery & history
- Method
- Telescope
- Name
- A catalogue designation from Willem Luyten's proper-motion survey (L 98-59); also TOI-175 from the TESS survey.
NASA's TESS mission found three transiting planets here in 2019; ESO's ESPRESSO spectrograph measured their masses and revealed a fourth planet in 2021, with a fifth, habitable-zone candidate confirmed by 2025 - building one of the best-characterised nearby planetary systems.
Images
Images from open archives · credit shown per image