Key parameters at a glance

A radius of 3.34 Earth radii
A mass of 11.10 Earth masses
Surface gravity around 1.00 g
An orbital period of 5.743 days
Semi-major axis 0.0625 AU
Equilibrium temperature 982 K (709 °C)
Distance from Earth 5,757.40 light-years
Earth Similarity Index 0.227
Travel time at Voyager 1 speed 101,531,806 years

Kepler-728 b Planet Profile

Physical Specs

Radius

3.34 R⊕

Radius (Jupiter)

0.298 R♃

Mass

11.10 M⊕

Mass (Jupiter)

0.035 M♃

Density

1.64 g/cm³

Surface Gravity

1.00 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.227

HZ Position Inner

Controversial No

Discovery

Year 2016

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#256of 1978

top 12.9%

This planet

3.34R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

K2-111 c 3.34 R⊕ Kepler-940 b 3.34 R⊕ TOI-1472 c 3.33 R⊕

Metric	Earth	Kepler-728 b	Jupiter
Radius (R⊕)	1.00	3.34	11.21
Mass (M⊕)	1.00	11.10	317.83
Density (g/cm³)	5.51	1.64	1.33
Surface Gravity (g)	1.00	1.00	2.53
Insolation (S⊕)	1.00	484.51	0.037

Star Catalogue Identifiers

TIC

TIC 159580427

Gaia DR2

Gaia DR2 2126639557538793088

Gaia DR3

Gaia DR3 2126639557538793088

System

Kepler-728

Percentile among Sub-Neptune cohort

Radius 3.340 R⊕ · percentile 87 / cohort 1978

Mass 11.100 M⊕ · percentile 80 / cohort 1978

Orbital period 5.74 d · percentile 16 / cohort 1946

Distance 1,765.23 pc · percentile 96 / cohort 1975

ESI 0.227 · percentile 11 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

5.743 days

Semi-major axis

0.0625 AU

Eccentricity

0.000

Inclination

90.00 °

Year Length

A year here lasts approximately 5.74 Earth days (1.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0625 AU.

Transit Fingerprint

Depth

0.124 %

Duration

3.453 h

Impact parameter b

0.640

Rp / R★

0.033212

Transit midpoint (BJD)

2,455,007.8983

Photometric dip

Transit produces a flux drop of 1,240 ppm lasting ≈ 3.45 h.

Extended Orbital Architecture

Planet / star radius ratio

0.033212

Semi-major axis / stellar radius

13.144

Impact parameter (b)

0.640

Transit mid-time (BJD)

2,455,007.8983

Angular separation (arcsec)

0.03540

Eq. Temperature

982K

(709 °C)

Insolation (S⊕)

484.51

Earth = 1.00

Earth Similarity (ESI)

0.227

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water.

Discovery Paper

Primary reference

Morton et al. 2016

Instrument

Kepler CCD Array

Publication

2016-05

Observation locale

Space

Discovery cohort

Planets confirmed in 2016 at Kepler (12 shown).

Kepler-1512 b · Rocky Terrestrial Kepler-1410 b · Super-Earth Kepler-560 b · Super-Earth Kepler-1389 b · Super-Earth Kepler-1450 b · Super-Earth Kepler-1544 b · Super-Earth Kepler-1459 b · Super-Earth Kepler-1638 b · Super-Earth Kepler-737 b · Super-Earth Kepler-1185 b · Super-Earth Kepler-1178 b · Rocky Terrestrial Kepler-1040 b · Sub-Neptune

Host System: Kepler-728

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,660 K — cooler than the Sun (5,778 K)

Estimated Age

4.07 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.930 R☉

Stellar Mass

0.950 M☉

Metallicity [Fe/H]

-0.03

Extended Stellar Properties

Surface gravity (log g)

4.490 dex

Stellar density

1.311 g/cm³

Metallicity ratio

[Fe/H]

Distance

1,765.23 parsec

Light-years 5,757.40 ly

V-band magnitude

15.59 mag

Voyager-speed travel 101,531,806 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

0.538 mas

Total Proper Motion

7.610 mas/yr

PM Right Ascension

2.46 mas/yr

PM Declination

-7.20 mas/yr

Galactic Cartesian (pc)

x = 0.254 · y = -0.658 · z = 0.709

Equatorial (J2000)

RA 291.09236° · Dec 45.11551°

Galactic ℓ, b

77.026° · 13.482°

Ecliptic λ, β

308.238° · 65.778°

HTM-20 index

1567969265