Confirmed Exoplanet Discovered 2019

TOI-216.02

A neptune-like orbiting the k-type orange TOI-216, located approximately 580.4 light-years from Earth.

Key parameters at a glance

  • A radius of 8.00 Earth radii
  • A mass of 18.75 Earth masses
  • Surface gravity around 0.29 g
  • An orbital period of 17.161 days
  • Semi-major axis 0.1293 AU
  • Equilibrium temperature 628 K (355 °C)
  • Distance from Earth 580.38 light-years
  • Earth Similarity Index 0.228
  • Travel time at Voyager 1 speed 10,234,971 years
  • Almost certainly tidally locked to its host star given the close orbit

1 sibling around TOI-216

TOI-216.02 shares its host star with 1 other confirmed planet. Side-by-side measurements below.

Planet Type Radius (R⊕) Mass (M⊕) Period (d) Eq. T (K) Year
TOI-216.02 this Neptune-like 8.00 18.75 17.161 628 2019
TOI-216.01 Gas Giant 10.10 177.98 34.526 497 2019

TOI-216.02 Planet Profile

Physical Specs

Radius
8.00 R⊕
Radius (Jupiter)
0.714 R♃
Mass
18.75 M⊕
Mass (Jupiter)
0.059 M♃
Density
0.34 g/cm³
Surface Gravity
0.29 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.228
HZ Position Inner
Controversial No

Discovery

Year 2019
Method Transit
Facility Transiting Exoplanet Survey Satellite (TESS)
Telescope 0.1 m TESS Telescope

Size rank in cohort

Rank by radius

#156of 574

top 27.0%

This planet

8.00R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

TOI-1836 b 8.00 R⊕ Kepler-1487 c 7.97 R⊕ TOI-1775 b 8.05 R⊕
Metric Earth TOI-216.02 Jupiter
Radius (R⊕)1.008.0011.21
Mass (M⊕)1.0018.75317.83
Density (g/cm³)5.510.341.33
Surface Gravity (g)1.000.292.53
Insolation (S⊕)1.0025.900.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 18.752 M⊕ Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 55652896

Gaia DR2

Gaia DR2 4664811297844004352

Gaia DR3

Gaia DR3 4664811297844004352

System

TOI-216

Percentile among Neptune-like cohort

Radius 8.000 R⊕ · percentile 73 / cohort 574
Mass 18.752 M⊕ · percentile 24 / cohort 574
Orbital period 17.16 d · percentile 49 / cohort 524
Distance 177.95 pc · percentile 37 / cohort 572
ESI 0.228 · percentile 34 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period
17.161 days
Semi-major axis
0.1293 AU
Eccentricity
0.160
Inclination
88.60 °

Year Length

A year here lasts approximately 17.16 Earth days (4.7% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.1293 AU.

Transit Fingerprint

Depth

0.475 %

Duration

2.062 h

Impact parameter b

0.980

Rp / R★

0.100000

Transit midpoint (BJD)

2,458,324.5911

Photometric dip

Transit produces a flux drop of 4,750 ppm lasting ≈ 2.06 h.

Extended Orbital Architecture

Planet / star radius ratio

0.100000

Semi-major axis / stellar radius

33.250

Impact parameter (b)

0.980

Transit mid-time (BJD)

2,458,324.5911

Long. of periastron (ω)

291.80°

Angular separation (arcsec)

0.72700

Eq. Temperature

628K

(355 °C)

Insolation (S⊕)

25.90

Earth = 1.00

Earth Similarity (ESI)

0.228

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water. Close-orbiting tidally-locked around a cool host.

Detection Signatures

Transit photometry

A transit dip has been observed from at least one telescope.

Transit timing variations

Gravitational interactions from neighbours have been detected.

Discovery Paper

Primary reference

Kipping et al. 2019

Instrument

TESS CCD Array

Publication

2019-07

Observation locale

Space

Discovery cohort

Planets confirmed in 2019 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).

LP 791-18 c · Sub-Neptune LTT 1445 A b · Super-Earth TOI-270 d · Sub-Neptune L 98-59 d · Super-Earth GJ 357 b · Rocky Terrestrial GJ 143 b · Sub-Neptune HD 23472 c · Super-Earth L 98-59 c · Super-Earth LP 791-18 b · Rocky Terrestrial TOI-270 c · Sub-Neptune HD 23472 b · Sub-Neptune TOI-270 b · Super-Earth

Host System: TOI-216

Spectral Class

K-type orange

Effective Temperature

5,026 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.748 R☉

Stellar Mass

0.770 M☉

Metallicity [Fe/H]

0.32

Extended Stellar Properties

Surface gravity (log g)

4.660 dex

Stellar density

2.380 g/cm³

Systemic radial velocity

36.30 km/s

Rotational v·sin i

0.84 km/s

Metallicity ratio

[M/H]

Distance
177.95 parsec
Light-years 580.38 ly
V-band magnitude
12.32 mag
Voyager-speed travel 10,234,971 yr

Multi-band Host Photometry — 11 bands

9.113.413.36B12.32V12.16Gaia11.57TESS10.76J10.33H10.22K10.17W110.24W210.12W39.08W4

Astrometric Data

Parallax

5.591 mas

Total Proper Motion

60.752 mas/yr

PM Right Ascension

-22.70 mas/yr

PM Declination

-56.35 mas/yr

Galactic Cartesian (pc)

x = 0.124 · y = 0.432 · z = -0.893

Equatorial (J2000)

RA 73.98001° · Dec -63.26033°

Galactic ℓ, b

273.409° · -36.914°

Ecliptic λ, β

18.493° · -82.476°

HTM-20 index

-812688575

Similar Worlds

HATS-72 b

Neptune-like · K-type orange

Radius 8.10 R⊕ · 416.1 ly

HD 177830 c

Neptune-like · K-type orange

Radius 7.87 R⊕ · 204.7 ly

K2-281 b

Neptune-like · K-type orange

Radius 8.18 R⊕ · 1,494.2 ly

HD 27894 c

Neptune-like · K-type orange

Radius 8.24 R⊕ · 142.9 ly

Kepler-489 b

Neptune-like · K-type orange

Radius 7.72 R⊕ · 1,205.6 ly

KMT-2021-BLG-1689L b

Neptune-like · K-type orange

Radius 7.71 R⊕ · 23,483.2 ly

Explore Related Categories

Neptune-like Planets Transit Discoveries Transiting Exoplanet Survey Satellite (TESS) Mission K-type orange Hosts