Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Volans |
Right ascension | 08h 18m 07.62144s [1] |
Declination | −68° 18′ 46.8054″ [1] |
Apparent magnitude (V) | 11.69±0.05 [2] |
Characteristics | |
Evolutionary stage | Red dwarf (main sequence) |
Spectral type | M3V [3] |
B−V colour index | +1.53 [2] |
R−I colour index | +1.28 [2] |
Variable type | None |
Astrometry | |
Radial velocity (Rv) | −6.10±0.19 [1] km/s |
Proper motion (μ) | RA: 94.794(18) mas/yr [1] Dec.: −340.084(20) mas/yr [1] |
Parallax (π) | 94.2664±0.0155 mas [1] |
Distance | 34.599 ± 0.006 ly (10.608 ± 0.002 pc) |
Details [4] | |
Mass | 0.2923±0.0067 M☉ |
Radius | 0.3155±0.0062 R☉ |
Luminosity (bolometric) | 0.0122±0.0010 L☉ |
Habitable zone inner limit | 0.090 au |
Habitable zone outer limit | 0.237 au |
Surface gravity (log g) | 4.91±0.02 cgs |
Temperature | 3415±60 [3] K |
Metallicity [Fe/H] | −0.46±0.26 [3] dex |
Rotation | 77.5±1.6 days |
Age | >800 [3] Myr |
Other designations | |
L 98-59, NLTT 19357, TOI-175, TIC 307210830, TYC 9193-2365-1, 2MASS J08180763-6818468 [5] | |
Database references | |
SIMBAD | data |
Exoplanet Archive | data |
L 98-59 (TOI-175, TIC 307210830) is a bright M dwarf star, located in the constellation of Volans, at a distance of 10.608 parsecs (34.60 light-years ), as measured by the Gaia spacecraft. [6]
Broadband photometry shows that it is an M3 dwarf star with three confirmed terrestrial-sized planets in transit, which were announced in March 2019 by TESS, [7] as well as two additional non-transiting planets, for a total of five known planets. The outermost planet is in the habitable zone. [8]
The planets b, c, and d of L 98-59 were discovered in 2019 by TESS. [7] The potential super-Venus planet L 98-59 e was discovered in 2021, along with potentially habitable super-Earth L 98-59 f. [3] [9] In September 2021, suggested tests of the abilities of the Hubble Space Telescope and the James Webb Space Telescope to detect and describe the atmospheric features of the three inner planets were reported. [10] Planet f was confirmed in 2025, along with the detection of an additional planet candidate. [8]
The two innermost confirmed planets, L 98-59 b and c, as well as L 98-59 e are possibly hot rocky worlds. L 98-59 d has a low density, indicating large amounts of water, potentially making up as much as 30% of its entire mass. It may therefore be covered in a deep global ocean. [11] Hubble observations of the three transiting planets in 2022 have found no clear evidence of atmospheres, with high mean molecular weight atmospheres, cloudy or hazy atmospheres, or no atmospheres all being consistent with the observed flat spectra. [12] [13] [14] One study found some evidence of an atmosphere on L 98-59 c, which has yet to be confirmed as of 2023. [15] Transmission spectroscopy by the JWST suggest that L 98-59 d might have a atmosphere rich in sulfur-compounds. [16]
Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
.06 [8] (unconfirmed) | ≥0.58±0.12 M🜨 | 0.0188±0.0004 | 1.7361+0.0007 −0.0008 | 0.027+0.040 −0.020 | — | — |
b | 0.46±0.11 M🜨 | 0.0223±0.0007 | 2.2531140(4) | 0.031+0.017 −0.016 | 88.08+0.23 −0.20 ° | 0.837±0.019 R🜨 |
c | 2.00±0.13 M🜨 | 0.0309±0.0010 | 3.6906764(4) | 0.002+0.002 −0.001 | 88.88+0.21 −0.17 ° | 1.329±0.029 R🜨 |
d | 1.64±0.07 M🜨 | 0.0494±0.0016 | 7.450729(2) | 0.006+0.007 −0.004 | 88.44±0.05 ° | 1.627±0.041 R🜨 |
e | ≥2.82±0.19 M🜨 | 0.0712±0.0022 | 12.8278±0.0018 | 0.012+0.009 −0.008 | 80–88.82° | — |
f | ≥2.8±0.3 M🜨 | 0.1052±0.0033 | 23.064±0.055 | 0.044+0.027 −0.028 | 74–89.20° | — |