Key parameters at a glance

A radius of 17.04 Earth radii
A mass of 152.56 Earth masses
Surface gravity around 0.53 g
An orbital period of 4.457 days
Semi-major axis 0.0608 AU
Equilibrium temperature 1,770 K (1497 °C)
Distance from Earth 1,514.89 light-years
Earth Similarity Index 0.050
Travel time at Voyager 1 speed 26,715,146 years

HAT-P-40 b Planet Profile

Physical Specs

Radius

17.04 R⊕

Radius (Jupiter)

1.520 R♃

Mass

152.56 M⊕

Mass (Jupiter)

0.480 M♃

Density

0.15 g/cm³

Surface Gravity

0.53 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.050

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

#108of 1771

top 6.0%

This planet

17.04R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

TOI-1181 b 17.03 R⊕ KELT-17 b 17.09 R⊕ MASCARA-4 b 16.98 R⊕

Metric	Earth	HAT-P-40 b	Jupiter
Radius (R⊕)	1.00	17.04	11.21
Mass (M⊕)	1.00	152.56	317.83
Density (g/cm³)	5.51	0.15	1.33
Surface Gravity (g)	1.00	0.53	2.53
Insolation (S⊕)	1.00	1,747.42	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	152.558 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 199671901

Gaia DR2

Gaia DR2 1962153854973972096

Gaia DR3

Gaia DR3 1962153854973972096

System

HAT-P-40

Percentile among Gas Giant cohort

Radius 17.038 R⊕ · percentile 94 / cohort 1771

Mass 152.558 M⊕ · percentile 12 / cohort 1747

Orbital period 4.46 d · percentile 33 / cohort 1533

Distance 464.47 pc · percentile 73 / cohort 1759

ESI 0.050 · percentile 4 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

4.457 days

Semi-major axis

0.0608 AU

Eccentricity

0.000

Inclination

88.30 °

Year Length

A year here lasts approximately 4.46 Earth days (1.2% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0608 AU.

Transit Fingerprint

Depth

0.650 %

Duration

6.137 h

Impact parameter b

0.174

Rp / R★

0.080700

Transit midpoint (BJD)

2,456,651.1337

Photometric dip

Transit produces a flux drop of 6,500 ppm lasting ≈ 6.14 h.

Extended Orbital Architecture

Planet / star radius ratio

0.080700

Semi-major axis / stellar radius

5.940

Impact parameter (b)

0.174

RV semi-amplitude (K)

58.100 m/s

Transit mid-time (BJD)

2,456,651.1337

Angular separation (arcsec)

0.13100

Eq. Temperature

1,770K

(1497 °C)

Insolation (S⊕)

1,747.42

Earth = 1.00

Earth Similarity (ESI)

0.050

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-39 b · Gas Giant HAT-P-41 b · Gas Giant

Host System: HAT-P-40

Spectral Class

F-type yellow-white

Effective Temperature

6,080 K — hotter than the Sun (5,778 K)

Estimated Age

2.70 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.940 R☉

Stellar Mass

1.030 M☉

Metallicity [Fe/H]

0.22

Extended Stellar Properties

Surface gravity (log g)

3.930 dex

Stellar density

0.200 g/cm³

Systemic radial velocity

-25.00 km/s

Rotational v·sin i

6.90 km/s

Metallicity ratio

[Fe/H]

Distance

464.47 parsec

Light-years 1,514.89 ly

V-band magnitude

11.34 mag

Voyager-speed travel 26,715,146 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

2.125 mas

Total Proper Motion

10.468 mas/yr

PM Right Ascension

8.96 mas/yr

PM Declination

-5.41 mas/yr

Galactic Cartesian (pc)

x = 0.638 · y = -0.291 · z = 0.713

Equatorial (J2000)

RA 335.51292° · Dec 45.45734°

Galactic ℓ, b

97.344° · -9.863°

Ecliptic λ, β

1.500° · 50.315°

HTM-20 index

1689889373