TOI-2267
Binary star in the constellation Cepheus
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TOI-2267 is a binary star located 73.5 light-years (22.5 parsecs) away from the Sun. The system has a visual apparent magnitude of 15.4, too faint to be seen with the naked eye.[5] It consists of two red dwarfs that are separated by only 8 AU.[4]
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Cepheus[1] |
| Right ascension | 04h 20m 12.64355s[2] |
| Declination | +84° 54′ 06.2765″[2] |
| Apparent magnitude (V) | 15.41[3] |
| Characteristics | |
| Evolutionary stage | main sequence + main sequence[4] |
| Spectral type | M5V+M6V[4] |
| Astrometry | |
| Radial velocity (Rv) | −19.0±0.3[4] km/s |
| Proper motion (μ) | RA: +182.388 mas/yr[2] Dec.: −213.503 mas/yr[2] |
| Parallax (π) | 44.3496±0.3556 mas[2] |
| Distance | 73.5 ± 0.6 ly (22.5 ± 0.2 pc) |
| Position (relative to A)[4] | |
| Component | B |
| Epoch of observation | 9 December 2021 |
| Angular distance | 0.384″ |
| Position angle | 279.7° |
| Projected separation | 8 AU |
| Details[4] | |
| A | |
| Mass | 0.1710±0.0079 M☉ |
| Radius | 0.2075±0.0225 R☉ |
| Luminosity | 0.0033±0.0003 L☉ |
| Surface gravity (log g) | 4.99±0.05 cgs |
| Temperature | 3030±100 K |
| Metallicity [Fe/H] | 0.164±0.11 dex |
| Rotation | 0.6958 days |
| Age | ≳1 Gyr |
| B | |
| Mass | 0.0989±0.0130 M☉ |
| Radius | 0.130±0.030 R☉ |
| Luminosity | 0.0011±0.0003 L☉ |
| Surface gravity (log g) | 5.28±0.18 cgs |
| Temperature | 2930±160 K |
| Metallicity [Fe/H] | 0.164±0.11 dex |
| Rotation | 0.4936 days |
| Age | ≳1 Gyr |
| Other designations | |
| G 222-3, LP 4-80, LSPM J0420+8454, NLTT 12645, TOI-2267, TIC 459837008[3] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
Planetary system
The star system hosts three confirmed Earth-sized planets, but it is not known which star each planet orbits. Two of the planets have similar orbital periods, so it is unlikely that all three planets orbit the same star, which would make TOI-2267 the second system known to host transiting planets around both stars.[4][6][a] This configuration of planets might give more insights into studying the formation and evolution of planets in compact binary star systems.[4] Alternatively, the planets may all orbit the same star in a very compact resonant configuration, which would make TOI-2267 the most compact exoplanetary system known.[8]
The discovery of the planets was announced in 2025, using data from TESS as well as ground-based telescopes. Initially only two planets could be confirmed, and the third remained a candidate.[4] A follow-up study a few months later confirmed the third planet.[8]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination (°) |
Radius |
|---|---|---|---|---|---|---|
| d[8] | — | 0.0174±0.0003 | 2.0344678(23) | — | 87.4±0.6 | 0.98±0.09 R🜨 |
| b | — | 0.0205±0.0025 | 2.2890900(12) | — | 90.35+0.85 −1.2 |
1.00±0.11 R🜨 |
| c | — | 0.0263+0.0040 −0.0036 |
3.4950412(22) | — | 89.66+1.6 −0.89 |
1.14±0.13 R🜨 |
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination (°) |
Radius |
|---|---|---|---|---|---|---|
| d[8] | — | 0.0145+0.0006 −0.0007 |
2.0344671(23) | — | 89.0+0.6 −0.7 |
1.77±0.43 R🜨 |
| b | — | 0.0127±0.0032 | 2.2890896(17) | — | 90.0±1.0 | 1.22±0.29 R🜨 |
| c | — | 0.0145+0.0045 −0.0037 |
3.4950404(28) | — | 89.2+2.4 −1.1 |
1.36±0.33 R🜨 |
Notes
- The previously known Kepler-132 system is a similar case; it is unknown which star each planet orbits, but they cannot all orbit the same star since two of them have almost the same period.[7]
- The parameters of the planets if they orbit the primary star.
- The parameters of the planets if they orbit the secondary star.