Detection and characterization of the temperate super-earth Gliese 48 b
Abstract
Gliese 48 is an M3.5V red dwarf exhibiting significant magnetic activity and a stellar rotation period of 51.5 d. In this work, we present a systematic re-analysis of radial velocities (RV) from CARMENES and decade-long HIRES observations, integrated with TESS space-based photometry. We identify a planet of undetermined composition, Gliese 48 b, with an orbital period P = 39.6299 ± 0.29 d and a minimum mass M sin i = 8.11 ± 1.63 M⊕. The planetary nature of the signal is confirmed by its temporal coherence over a 15-year baseline and its achromaticity between visible and near-infrared channels. TESS photometry from Sectors 18, 19, 24, and 25 (218.6 d total baseline, 66,983 cadences) reveals no transit at P = 39.63 d (FAP > 10%, BLS). An injection-and-recovery test demonstrates that a 1287 ppm transit signal corresponding to a minimum-radius 1.69 R⊕ planet would have been detected with Signal-to-Pink-Noise Ratio SPNR > 7, ruling out a transiting geometry with high confidence. The orbital inclination is constrained to i < 89.3∘. With an incident stellar flux Seff ≈ 0.889 S⊕ and bolometric luminosity L* = 0.0273 ± 0.0023 L⊙, Gliese 48 b lies near the inner edge of the Conservative Habitable Zone and within the Optimistic HZ, making it one of the most astrobiologically compelling temperate Super-Earths orbiting an M-dwarf.
Versions
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BibTeX
@misc{conzo2026detection,
title = {{Detection and characterization of the temperate super-earth Gliese 48 b}},
author = {G. Conzo and M. Moriconi and S. A. Corrêa Jr},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2605.11123},
eprint = {2605.11123},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2605.11123},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Detection and characterization of the temperate super-earth Gliese 48 b
AU - G. Conzo
AU - M. Moriconi
AU - S. A. Corrêa Jr
PY - 2026
DA - 2026/10/29
PB - arXiv
DO - 10.48550/arxiv.2605.11123
UR - https://arxiv.org/abs/2605.11123
AB - Gliese 48 is an M3.5V red dwarf exhibiting significant magnetic activity and a stellar rotation period of 51.5 d. In this work, we present a systematic re-analysis of radial velocities (RV) from CARMENES and decade-long HIRES observations, integrated with TESS space-based photometry. We identify a planet of undetermined composition, Gliese 48 b, with an orbital period P = 39.6299 ± 0.29 d and a minimum mass M sin i = 8.11 ± 1.63 M_⊕. The planetary nature of the signal is confirmed by its temporal coherence over a 15-year baseline and its achromaticity between visible and near-infrared channels. TESS photometry from Sectors 18, 19, 24, and 25 (218.6 d total baseline, 66,983 cadences) reveals no transit at P = 39.63 d (FAP > 10%, BLS). An injection-and-recovery test demonstrates that a 1287 ppm transit signal corresponding to a minimum-radius 1.69 R_⊕ planet would have been detected with Signal-to-Pink-Noise Ratio SPNR > 7, ruling out a transiting geometry with high confidence. The orbital inclination is constrained to i < 89.3^∘. With an incident stellar flux S_eff ≈ 0.889 S_⊕ and bolometric luminosity L_* = 0.0273 ± 0.0023 L_⊙, Gliese 48 b lies near the inner edge of the Conservative Habitable Zone and within the Optimistic HZ, making it one of the most astrobiologically compelling temperate Super-Earths orbiting an M-dwarf.
ER -