Key parameters at a glance
- A radius of 11.32 Earth radii
- A mass of 875.62 Earth masses
- Surface gravity around 6.83 g
- An orbital period of 260.790 days
- Semi-major axis 0.8280 AU
- Equilibrium temperature 348 K (75 °C)
- Distance from Earth 380.58 light-years
- Earth Similarity Index 0.472
- Travel time at Voyager 1 speed 6,711,442 years
Context from the literature
TOI-2180 b is a giant exoplanet orbiting the G-type star TOI-2180, also known as HD 238894. It was discovered with the help of the Transiting Exoplanet Survey Satellite and is currently the exoplanet with the longest orbital period TESS was able to uncover. TOI-2180 b orbits its host star every 260.16 days.
Excerpted from Wikipedia · full article
TOI-2180 b Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#1611of 1771
top 90.9%
This planet
11.32R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | TOI-2180 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 11.32 | 11.21 |
| Mass (M⊕) | 1.00 | 875.62 | 317.83 |
| Density (g/cm³) | 5.51 | 3.32 | 1.33 |
| Surface Gravity (g) | 1.00 | 6.83 | 2.53 |
| Insolation (S⊕) | 1.00 | 2.71 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 875.617 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 298663873
Gaia DR2
Gaia DR2 2151078741786155008
Gaia DR3
Gaia DR3 2151078741786155008
System
TOI-2180
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 260.79 Earth days (71.4% of a terrestrial year) on a highly eccentric trajectory at a mean orbital distance of 0.8280 AU.
Transit Fingerprint
Depth
0.475 %
Duration
24.096 h
Impact parameter b
0.100
Transit midpoint (BJD)
2,458,830.7652
Photometric dip
Transit produces a flux drop of 4,748 ppm lasting ≈ 24.10 h.
Extended Orbital Architecture
Impact parameter (b)
0.100
RV semi-amplitude (K)
87.750 m/s
Transit mid-time (BJD)
2,458,830.7652
Long. of periastron (ω)
-43.80°
Angular separation (arcsec)
7.10000
Eq. Temperature
348K
(75 °C)
Insolation (S⊕)
2.71
Earth = 1.00
Earth Similarity (ESI)
0.472
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — liquid water is physically possible with adequate atmospheric pressure.
Detection Signatures
Transit photometry
A transit dip has been observed from at least one telescope.
Radial velocity
Stellar wobble has been measured spectroscopically.
Transit timing variations
Gravitational interactions from neighbours have been detected.
Discovery Paper
Primary reference
Dalba et al. 2022Instrument
TESS CCD Array
Publication
2022-02
Observation locale
Space
Discovery cohort
Planets confirmed in 2022 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).
Host System: TOI-2180
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,695 K — cooler than the Sun (5,778 K)
Estimated Age
8.10 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
1.636 R☉
Stellar Mass
1.111 M☉
Metallicity [Fe/H]
0.25
Extended Stellar Properties
Surface gravity (log g)
4.057 dex
Stellar density
0.359 g/cm³
Rotational v·sin i
2.20 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
8.541 mas
Total Proper Motion
41.562 mas/yr
PM Right Ascension
-10.54 mas/yr
PM Declination
-40.20 mas/yr
Galactic Cartesian (pc)
x = 0.076 · y = -0.544 · z = 0.835
Equatorial (J2000)
RA 277.94363° · Dec 56.65068°
Galactic ℓ, b
85.746° · 25.013°
Ecliptic λ, β
294.425° · 79.414°
HTM-20 index
-191609370
Similar Worlds
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TOI-5542 b
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TOI-2184 b
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TOI-199 c
Gas Giant · G-type yellow (Sun-like)
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