Key parameters at a glance

A radius of 9.34 Earth radii
A mass of 87.08 Earth masses
Surface gravity around 1.00 g
An orbital period of 282.525 days
Semi-major axis 0.8330 AU
Equilibrium temperature 295 K (22 °C)
Distance from Earth 1,121.53 light-years
Earth Similarity Index 0.441
Travel time at Voyager 1 speed 19,778,177 years

Context from the literature

PH2, also known as Kepler-86, or KIC 12735740, is an F-type main-sequence star 1,120 light-years distant within the constellation Cygnus. Roughly the size and temperature of the Sun, PH2 gained prominence when it was known to be the host of one of 42 planet candidates detected by the Planet Hunters citizen science project in its second data release. The candidate orbiting around PH2, known as PH2b, had been determined to have a spurious detection probability of only 0.08%, thus effectively confirming its existence as a planet.

Excerpted from Wikipedia · full article

PH2 b Planet Profile

Physical Specs

Radius

9.34 R⊕

Radius (Jupiter)

0.833 R♃

Mass

87.08 M⊕

Mass (Jupiter)

0.274 M♃

Density

0.58 g/cm³

Surface Gravity

1.00 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.441

HZ Position Habitable

Controversial No

Discovery

Year 2013

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#54of 574

top 9.2%

This planet

9.34R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

HD 24040 c 9.35 R⊕ HD 33142 d 9.32 R⊕ HD 137388 b 9.32 R⊕

Metric	Earth	PH2 b	Jupiter
Radius (R⊕)	1.00	9.34	11.21
Mass (M⊕)	1.00	87.08	317.83
Density (g/cm³)	5.51	0.58	1.33
Surface Gravity (g)	1.00	1.00	2.53
Insolation (S⊕)	1.00	1.20	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	87.085 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 416279912

Gaia DR2

Gaia DR2 2139300262131379584

Gaia DR3

Gaia DR3 2139300262131379584

System

PH2

Percentile among Neptune-like cohort

Radius 9.337 R⊕ · percentile 91 / cohort 574

Mass 87.085 M⊕ · percentile 89 / cohort 574

Orbital period 282.53 d · percentile 93 / cohort 524

Distance 343.86 pc · percentile 50 / cohort 572

ESI 0.441 · percentile 79 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period

282.525 days

Semi-major axis

0.8330 AU

Eccentricity

0.215

Inclination

89.90 °

Year Length

A year here lasts approximately 282.53 Earth days (77.4% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.8330 AU.

Transit Fingerprint

Depth

0.815 %

Duration

10.810 h

Impact parameter b

0.297

Rp / R★

0.090300

Transit midpoint (BJD)

2,455,196.0677

Photometric dip

Transit produces a flux drop of 8,154 ppm lasting ≈ 10.81 h.

Extended Orbital Architecture

Planet / star radius ratio

0.090300

Semi-major axis / stellar radius

188.900

Impact parameter (b)

0.297

RV semi-amplitude (K)

9.000 m/s

Transit mid-time (BJD)

2,455,196.0677

Long. of periastron (ω)

24.00°

Angular separation (arcsec)

2.42000

Eq. Temperature

295K

(22 °C)

Insolation (S⊕)

1.20

Earth = 1.00

Earth Similarity (ESI)

0.441

0 = alien, 1 = Earth-identical

Within the conservative habitable zone — 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.

Discovery Paper

Primary reference

Wang et al. 2013

Instrument

Kepler CCD Array

Publication

2013-10

Observation locale

Space

Discovery cohort

Planets confirmed in 2013 at Kepler (12 shown).

Kepler-69 c · Super-Earth Kepler-61 b · Sub-Neptune Kepler-62 e · Super-Earth KOI-351 f · Sub-Neptune Kepler-62 f · Super-Earth KOI-351 e · Sub-Neptune Kepler-1704 b · Gas Giant Kepler-37 d · Sub-Neptune Kepler-282 e · Sub-Neptune KOI-351 h · Gas Giant KOI-351 d · Sub-Neptune Kepler-114 c · Super-Earth

Host System: PH2

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,734 K — cooler than the Sun (5,778 K)

Estimated Age

4.10 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.949 R☉

Stellar Mass

0.966 M☉

Metallicity [Fe/H]

0.02

Extended Stellar Properties

Surface gravity (log g)

4.470 dex

Stellar density

1.600 g/cm³

Systemic radial velocity

-18.73 km/s

Rotational v·sin i

1.43 km/s

Rotation period

22.60 days

Activity index (log R'HK)

-4.848

Metallicity ratio

[Fe/H]

Distance

343.86 parsec

Light-years 1,121.53 ly

V-band magnitude

12.65 mag

Voyager-speed travel 19,778,177 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

2.880 mas

Total Proper Motion

16.376 mas/yr

PM Right Ascension

3.37 mas/yr

PM Declination

16.03 mas/yr

Galactic Cartesian (pc)

x = 0.208 · y = -0.580 · z = 0.788

Equatorial (J2000)

RA 289.76362° · Dec 51.96268°

Galactic ℓ, b

83.153° · 17.051°

Ecliptic λ, β

313.604° · 72.417°

HTM-20 index

14718245

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