Key parameters at a glance

A radius of 17.61 Earth radii
A mass of 190.37 Earth masses
Surface gravity around 0.61 g
An orbital period of 3.544 days
Semi-major axis 0.0509 AU
Equilibrium temperature 1,752 K (1479 °C)
Distance from Earth 2,273.32 light-years
Earth Similarity Index 0.053
Travel time at Voyager 1 speed 40,090,002 years

HAT-P-39 b Planet Profile

Physical Specs

Radius

17.61 R⊕

Radius (Jupiter)

1.571 R♃

Mass

190.37 M⊕

Mass (Jupiter)

0.599 M♃

Density

0.19 g/cm³

Surface Gravity

0.61 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.053

HZ Position Inner

Controversial No

Discovery

Year 2012

Method Transit

Facility HATNet

Telescope Canon 200mm f/1.8L

Size rank in cohort

Rank by radius

#90of 1771

top 5.0%

This planet

17.61R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

HATS-39 b 17.60 R⊕ KELT-18 b 17.60 R⊕ WASP-172 b 17.60 R⊕

Metric	Earth	HAT-P-39 b	Jupiter
Radius (R⊕)	1.00	17.61	11.21
Mass (M⊕)	1.00	190.37	317.83
Density (g/cm³)	5.51	0.19	1.33
Surface Gravity (g)	1.00	0.61	2.53
Insolation (S⊕)	1.00	1,915.69	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	190.372 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 14770122

Gaia DR2

Gaia DR2 3169391577586325120

Gaia DR3

Gaia DR3 3169391577586325120

System

HAT-P-39

Percentile among Gas Giant cohort

Radius 17.609 R⊕ · percentile 95 / cohort 1771

Mass 190.372 M⊕ · percentile 18 / cohort 1747

Orbital period 3.54 d · percentile 23 / cohort 1533

Distance 697.00 pc · percentile 81 / cohort 1759

ESI 0.053 · percentile 6 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

3.544 days

Semi-major axis

0.0509 AU

Eccentricity

0.000

Inclination

87.00 °

Year Length

A year here lasts approximately 3.54 Earth days (1.0% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0509 AU.

Transit Fingerprint

Depth

0.999 %

Duration

4.188 h

Impact parameter b

0.349

Rp / R★

0.099300

Transit midpoint (BJD)

2,455,208.7505

Photometric dip

Transit produces a flux drop of 9,990 ppm lasting ≈ 4.19 h.

Extended Orbital Architecture

Planet / star radius ratio

0.099300

Semi-major axis / stellar radius

6.740

Impact parameter (b)

0.349

RV semi-amplitude (K)

63.600 m/s

Transit mid-time (BJD)

2,455,208.7505

Angular separation (arcsec)

0.07300

Eq. Temperature

1,752K

(1479 °C)

Insolation (S⊕)

1,915.69

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

Hartman et al. 2012

Instrument

2K CCD Sensor

Publication

2012-11

Observation locale

Ground

Discovery cohort

Planets confirmed in 2012 at HATNet (5 shown).

HAT-P-38 b · Neptune-like HAT-P-42 b · Gas Giant HAT-P-43 b · Gas Giant HAT-P-40 b · Gas Giant HAT-P-41 b · Gas Giant

Host System: HAT-P-39

Spectral Class

F-type yellow-white

Effective Temperature

6,430 K — hotter than the Sun (5,778 K)

Estimated Age

2.00 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.625 R☉

Stellar Mass

1.404 M☉

Metallicity [Fe/H]

0.19

Extended Stellar Properties

Surface gravity (log g)

4.160 dex

Stellar density

0.349 g/cm³

Systemic radial velocity

28.42 km/s

Rotational v·sin i

12.70 km/s

Metallicity ratio

[Fe/H]

Distance

697.00 parsec

Light-years 2,273.32 ly

V-band magnitude

12.28 mag

Voyager-speed travel 40,090,002 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

1.406 mas

Total Proper Motion

8.665 mas/yr

PM Right Ascension

1.12 mas/yr

PM Declination

-8.59 mas/yr

Galactic Cartesian (pc)

x = -0.384 · y = 0.871 · z = 0.306

Equatorial (J2000)

RA 113.75825° · Dec 17.83003°

Galactic ℓ, b

201.417° · 17.446°

Ecliptic λ, β

112.600° · -3.764°

HTM-20 index

1488535565