Gliese 48 b
 Artist's impression of Gliese 48b orbiting its star | |
| Discovery[1][2] | |
|---|---|
| Discovered by |
|
| Discovery date | May 2026 |
| Radial velocity | |
| Designations | |
| |
| Orbital characteristics[1] | |
| 0.1752±0.0011 AU | |
| Eccentricity | 0 (fixed) |
| 39.6299±0.29 d | |
| Inclination | < 89.3° |
| Semi-amplitude | 2.38±0.24 m/s |
| Star | Ross 318 |
| Physical characteristics | |
| 1.69±0.08 R🜨 | |
| Mass | ≥8.11±1.63 M🜨 |
| Temperature | Teq: 271 K (−2 °C) |
Gliese 48 b (also known as Ross 318 b) is an exoplanet orbiting within the habitable zone of the red dwarf star Gliese 48 (TIC 379084450). Located approximately 26.852 light-years (8.233 parsecs) from Earth, this temperate world is classified as a Super-Earth.[2] Following peer review, the discovery was officially published in the Open European Journal on Variable Stars (OEJV).[1]
Gliese 48 b orbits its parent star at a distance of about 0.1752 AU (26,210,000 km; 16,290,000 mi) with an orbital period of approximately 39.63 Earth days.[1] While it has not been observed to transit its star, its minimum mass is 8.11 M🜨, with a measured radius of about 1.69 R⊕.[1] Receiving a substantial fraction of the stellar flux, it is located within the conservative habitable zone and is a candidate for future atmospheric characterization.[1][2]
Discovery
[edit]The discovery of Ross 318 b was announced in May 2026 and subsequently peer-reviewed and published in the OEJV.[1] The detection utilized a systematic re-analysis of radial velocity (RV) measurements from the CARMENES and HIRES spectrographs spanning over 15 years. The signal's validity was evaluated by its temporal coherence and achromatic nature across visible and near-infrared wavelengths.[1]
Photometric data from the TESS was used to search for transits. Although no transit events were detected, these observations allowed researchers to constrain the orbital inclination to under 89.3° and rule out larger transiting companions.[1] Data and updates for the system are also tracked by the NASA Exoplanet Archive and ExoFOP-TESS.[3]
Physical properties
[edit]Ross 318 b orbits a relatively active M-dwarf star. The planet's orbit is modeled as circular ($e=0$).[1] With a minimum mass of 8.11±1.63 M🜨 and a radius of 1.69±0.08 R🜨, it sits comfortably within the super-Earth regime.[1]
The planet is located within the conservative habitable zone of Ross 318. Its equilibrium temperature is estimated at 271 K (−2 °C; 28 °F).[1] Because of its close proximity to the M-dwarf host, the planet is likely tidally locked, though a dense atmosphere could potentially redistribute heat between hemispheres.[1]
Host star
[edit]Ross 318 (Gliese 48, TIC 379084450) is an M3.5V red dwarf with a mass of approximately 0.462 M☉.[1] The star exhibits significant magnetic activity, requiring careful separation of stellar activity signals from the planetary radial velocity variations during analysis.[1]
See also
[edit]References
[edit]- 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Conzo, G.; Moriconi, M.; Corrêa, S. A. (2026). "Detection and Characterization of the Temperate Super-Earth Ross 318 b" (PDF). Open European Journal on Variable Stars. 0273. Retrieved 1 July 2026.
- 1 2 3 "Planet Ross 318 b". The Extrasolar Planets Encyclopaedia. Retrieved 1 July 2026.
- ↑ "Gliese 48 Overview". NASA Exoplanet Archive. Retrieved 1 July 2026.