Key parameters at a glance

A radius of 6.81 Earth radii
A mass of 37.30 Earth masses
Surface gravity around 0.80 g
An orbital period of 1.993 days
Semi-major axis 0.0238 AU
Equilibrium temperature 675 K (402 °C)
Earth Similarity Index 0.242
Almost certainly tidally locked to its host star given the close orbit

Kepler-1984 b Planet Profile

Physical Specs

Radius

6.81 R⊕

Radius (Jupiter)

0.608 R♃

Mass

37.30 M⊕

Mass (Jupiter)

0.117 M♃

Density

0.65 g/cm³

Surface Gravity

0.80 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.242

HZ Position Inner

Controversial No

Discovery

Year 2023

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#217of 574

top 37.6%

This planet

6.81R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

TOI-2374 b 6.81 R⊕ TOI-1248 b 6.81 R⊕ Kepler-857 b 6.80 R⊕

Metric	Earth	Kepler-1984 b	Jupiter
Radius (R⊕)	1.00	6.81	11.21
Mass (M⊕)	1.00	37.30	317.83
Density (g/cm³)	5.51	0.65	1.33
Surface Gravity (g)	1.00	0.80	2.53
Insolation (S⊕)	1.00	48.82	0.037

Star Catalogue Identifiers

TIC

TIC 137089954

Gaia DR2

Gaia DR2 2101508501301083520

Gaia DR3

Gaia DR3 2101508501301083520

System

Kepler-1984

Percentile among Neptune-like cohort

Radius 6.810 R⊕ · percentile 62 / cohort 574

Mass 37.300 M⊕ · percentile 60 / cohort 574

Orbital period 1.99 d · percentile 2 / cohort 524

ESI 0.242 · percentile 39 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period

1.993 days

Semi-major axis

0.0238 AU

Eccentricity

0.000

Inclination

55.11 °

Year Length

A year here lasts approximately 1.99 Earth days (0.5% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0238 AU.

Transit Fingerprint

Depth

0.031 %

Duration

2.066 h

Impact parameter b

1.127

Rp / R★

0.148573

Transit midpoint (BJD)

2,454,964.7057

Photometric dip

Transit produces a flux drop of 315 ppm lasting ≈ 2.07 h.

Extended Orbital Architecture

Planet / star radius ratio

0.148573

Semi-major axis / stellar radius

1.971

Impact parameter (b)

1.127

Transit mid-time (BJD)

2,454,964.7057

Eq. Temperature

675K

(402 °C)

Insolation (S⊕)

48.82

Earth = 1.00

Earth Similarity (ESI)

0.242

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.

Discovery Paper

Primary reference

Valizadegan et al. 2023

Instrument

Kepler CCD Array

Publication

2023-05

Observation locale

Space

Discovery cohort

Planets confirmed in 2023 at Kepler (12 shown).

Kepler-1126 c · Super-Earth Kepler-2000 c · Super-Earth Kepler-1052 c · Sub-Neptune Kepler-311 d · Sub-Neptune Kepler-1996 c · Sub-Neptune Kepler-1162 c · Super-Earth Kepler-1996 b · Sub-Neptune Kepler-1610 c · Sub-Neptune Kepler-1801 c · Sub-Neptune Kepler-1995 b · Neptune-like Kepler-1992 b · Rocky Terrestrial Kepler-1986 b · Super-Earth

Host System: Kepler-1984

Spectral Class

M-type red dwarf

Effective Temperature

3,638 K — cooler than the Sun (5,778 K)

Estimated Age

13.80 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.420 R☉

Stellar Mass

0.450 M☉

Metallicity [Fe/H]

-0.14

Extended Stellar Properties

Surface gravity (log g)

4.844 dex

Stellar density

0.036 g/cm³

Metallicity ratio

[Fe/H]

Multi-band Host Photometry — 16 bands

Astrometric Data

Total Proper Motion

11.737 mas/yr

PM Right Ascension

11.39 mas/yr

PM Declination

-2.84 mas/yr

Galactic Cartesian (pc)

x = 0.275 · y = -0.706 · z = 0.652

Equatorial (J2000)

RA 291.28504° · Dec 40.73002°

Galactic ℓ, b

73.037° · 11.461°

Ecliptic λ, β

305.312° · 61.585°

HTM-20 index

1615870373