Key parameters at a glance
- A radius of 1.42 Earth radii
- A mass of 3.07 Earth masses
- Surface gravity around 1.52 g
- An orbital period of 0.669 days
- Semi-major axis 0.0116 AU
- Equilibrium temperature 1,000 K (727 °C)
- Distance from Earth 122.68 light-years
- Earth Similarity Index 0.304
- Travel time at Voyager 1 speed 2,163,542 years
- Almost certainly tidally locked to its host star given the close orbit
TOI-1685 b Planet Profile
Physical Specs
Classification
Planet Type
Super-Earth
Discovery
Size rank in cohort
Rank by radius
#882of 1176
top 74.9%
This planet
1.42R⊕
Super-Earth median
1.60R⊕
Nearest-size peers
| Metric | Earth | TOI-1685 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 1.42 | 11.21 |
| Mass (M⊕) | 1.00 | 3.07 | 317.83 |
| Density (g/cm³) | 5.51 | 5.30 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.52 | 2.53 |
| Insolation (S⊕) | 1.00 | 213.00 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 3.070 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 28900646
Gaia DR2
Gaia DR2 252366608956186240
Gaia DR3
Gaia DR3 252366608956186240
System
TOI-1685
Percentile among Super-Earth cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts roughly 16.1 hours long on a nearly circular orbit at a mean orbital distance of 0.0116 AU.
Transit Fingerprint
Depth
0.125 %
Duration
0.904 h
Impact parameter b
0.310
Rp / R★
0.028180
Transit midpoint (BJD)
2,458,816.2257
Photometric dip
Transit produces a flux drop of 1,254 ppm lasting ≈ 0.90 h.
Extended Orbital Architecture
Planet / star radius ratio
0.028180
Semi-major axis / stellar radius
5.410
Impact parameter (b)
0.310
RV semi-amplitude (K)
3.760 m/s
Occultation depth
0.012 ppm
Transit mid-time (BJD)
2,458,816.2257
Long. of periastron (ω)
90.00°
Angular separation (arcsec)
0.30900
Eq. Temperature
1,000K
(727 °C)
Insolation (S⊕)
213.00
Earth = 1.00
Earth Similarity (ESI)
0.304
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched. Close-orbiting tidally-locked around a cool host.
Detection Signatures
Transit photometry
A transit dip has been observed from at least one telescope.
Radial velocity
Stellar wobble has been measured spectroscopically.
Discovery Paper
Primary reference
Bluhm et al. 2021Instrument
TESS CCD Array
Publication
2021-06
Observation locale
Space
Discovery cohort
Planets confirmed in 2021 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).
Host System: TOI-1685
Spectral Class
M-type red dwarf
Effective Temperature
3,470 K — cooler than the Sun (5,778 K)
Estimated Age
1.40 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.462 R☉
Stellar Mass
0.466 M☉
Metallicity [Fe/H]
0.01
Extended Stellar Properties
Surface gravity (log g)
4.680 dex
Stellar density
5.797 g/cm³
Systemic radial velocity
-43.76 km/s
Rotational v·sin i
2.00 km/s
Rotation period
18.66 days
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
26.556 mas
Total Proper Motion
94.783 mas/yr
PM Right Ascension
37.82 mas/yr
PM Declination
-86.91 mas/yr
Galactic Cartesian (pc)
x = 0.267 · y = 0.680 · z = 0.682
Equatorial (J2000)
RA 68.59395° · Dec 43.03704°
Galactic ℓ, b
160.159° · -3.156°
Ecliptic λ, β
73.413° · 20.822°
HTM-20 index
337127432
Observation Record
Transmission spectra
9
Emission spectra
1
Archive notes
1
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