Key parameters at a glance

A radius of 16.14 Earth radii
A mass of 371.86 Earth masses
Surface gravity around 1.43 g
An orbital period of 4.127 days
Semi-major axis 0.0568 AU
Equilibrium temperature 2,061 K (1788 °C)
Distance from Earth 642.04 light-years
Earth Similarity Index 0.053
Travel time at Voyager 1 speed 11,322,456 years

HD 2685 b Planet Profile

Physical Specs

Radius

16.14 R⊕

Radius (Jupiter)

1.440 R♃

Mass

371.86 M⊕

Mass (Jupiter)

1.170 M♃

Density

0.49 g/cm³

Surface Gravity

1.43 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.053

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

#146of 1771

top 8.2%

This planet

16.14R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

2MASS J02192210-3925225 b 16.14 R⊕ HAT-P-30 b 16.14 R⊕ WASP-118 b 16.14 R⊕

Metric	Earth	HD 2685 b	Jupiter
Radius (R⊕)	1.00	16.14	11.21
Mass (M⊕)	1.00	371.86	317.83
Density (g/cm³)	5.51	0.49	1.33
Surface Gravity (g)	1.00	1.43	2.53
Insolation (S⊕)	1.00	1,436.49	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	371.861 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

HD 2685

TIC

TIC 267263253

Gaia DR2

Gaia DR2 4684205720883329920

Gaia DR3

Gaia DR3 4684205720883329920

System

HD 2685

Percentile among Gas Giant cohort

Radius 16.141 R⊕ · percentile 92 / cohort 1771

Mass 371.861 M⊕ · percentile 39 / cohort 1747

Orbital period 4.13 d · percentile 30 / cohort 1533

Distance 196.85 pc · percentile 50 / cohort 1759

ESI 0.053 · percentile 6 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

4.127 days

Semi-major axis

0.0568 AU

Eccentricity

0.091

Inclination

89.25 °

Year Length

A year here lasts approximately 4.13 Earth days (1.1% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0568 AU.

Transit Fingerprint

Depth

1.083 %

Duration

4.405 h

Impact parameter b

0.258

Rp / R★

0.094670

Transit midpoint (BJD)

2,458,325.7830

Photometric dip

Transit produces a flux drop of 10,831 ppm lasting ≈ 4.41 h.

Extended Orbital Architecture

Planet / star radius ratio

0.094670

Semi-major axis / stellar radius

7.697

Impact parameter (b)

0.258

RV semi-amplitude (K)

117.400 m/s

Transit mid-time (BJD)

2,458,325.7830

Long. of periastron (ω)

184.36°

Angular separation (arcsec)

0.28900

Eq. Temperature

2,061K

(1788 °C)

Insolation (S⊕)

1,436.49

Earth = 1.00

Earth Similarity (ESI)

0.053

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched.

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

Jones et al. 2019

Instrument

TESS CCD Array

Publication

2019-05

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: HD 2685

Spectral Class

F-type yellow-white

Effective Temperature

6,801 K — hotter than the Sun (5,778 K)

Estimated Age

1.31 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.560 R☉

Stellar Mass

1.430 M☉

Metallicity [Fe/H]

0.02

Extended Stellar Properties

Surface gravity (log g)

4.210 dex

Stellar density

0.515 g/cm³

Systemic radial velocity

3.64 km/s

Rotational v·sin i

15.40 km/s

Metallicity ratio

[Fe/H]

Distance

196.85 parsec

Light-years 642.04 ly

V-band magnitude

9.60 mag

Voyager-speed travel 11,322,456 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

5.051 mas

Total Proper Motion

7.568 mas/yr

PM Right Ascension

-2.97 mas/yr

PM Declination

6.96 mas/yr

Galactic Cartesian (pc)

x = 0.235 · y = 0.030 · z = -0.972

Equatorial (J2000)

RA 7.32892° · Dec -76.30403°

Galactic ℓ, b

304.658° · -40.750°

Ecliptic λ, β

303.204° · -64.610°

HTM-20 index

-82333533