Key parameters at a glance

A radius of 14.02 Earth radii
A mass of 292.72 Earth masses
Surface gravity around 1.49 g
An orbital period of 4.204 days
Semi-major axis 0.0541 AU
Equilibrium temperature 1,367 K (1094 °C)
Distance from Earth 1,989.02 light-years
Earth Similarity Index 0.093
Travel time at Voyager 1 speed 35,076,423 years

HATS-55 b Planet Profile

Physical Specs

Radius

14.02 R⊕

Radius (Jupiter)

1.251 R♃

Mass

292.72 M⊕

Mass (Jupiter)

0.921 M♃

Density

0.59 g/cm³

Surface Gravity

1.49 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.093

HZ Position Inner

Controversial No

Discovery

Year 2019

Method Transit

Facility HATSouth

Telescope 0.18 m Takahashi Epsilon Astrograph

Size rank in cohort

Rank by radius

#406of 1771

top 22.9%

This planet

14.02R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

HATS-29 b 14.02 R⊕ Ross 458 c 14.01 R⊕ WASP-185 b 14.01 R⊕

Metric	Earth	HATS-55 b	Jupiter
Radius (R⊕)	1.00	14.02	11.21
Mass (M⊕)	1.00	292.72	317.83
Density (g/cm³)	5.51	0.59	1.33
Surface Gravity (g)	1.00	1.49	2.53
Insolation (S⊕)	1.00	355.91	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	292.721 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 114299824

Gaia DR2

Gaia DR2 5592019557950033536

Gaia DR3

Gaia DR3 5592019557950033536

System

HATS-55

Percentile among Gas Giant cohort

Radius 14.022 R⊕ · percentile 77 / cohort 1771

Mass 292.721 M⊕ · percentile 32 / cohort 1747

Orbital period 4.20 d · percentile 31 / cohort 1533

Distance 609.84 pc · percentile 79 / cohort 1759

ESI 0.093 · percentile 24 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

4.204 days

Semi-major axis

0.0541 AU

Eccentricity

0.092

Inclination

86.32 °

Year Length

A year here lasts approximately 4.20 Earth days (1.2% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0541 AU.

Transit Fingerprint

Depth

1.208 %

Duration

2.784 h

Impact parameter b

0.662

Rp / R★

0.114100

Transit midpoint (BJD)

2,457,413.1304

Photometric dip

Transit produces a flux drop of 12,080 ppm lasting ≈ 2.78 h.

Extended Orbital Architecture

Planet / star radius ratio

0.114100

Semi-major axis / stellar radius

10.330

Impact parameter (b)

0.662

RV semi-amplitude (K)

102.800 m/s

Transit mid-time (BJD)

2,457,413.1304

Angular separation (arcsec)

0.08870

Eq. Temperature

1,367K

(1094 °C)

Insolation (S⊕)

355.91

Earth = 1.00

Earth Similarity (ESI)

0.093

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

Espinoza et al. 2019

Instrument

Apogee 4K CCD Sensor

Publication

2019-08

Observation locale

Ground

Discovery cohort

Planets confirmed in 2019 at HATSouth (5 shown).

HATS-57 b · Gas Giant HATS-54 b · Gas Giant HATS-58 A b · Gas Giant HATS-70 b · Gas Giant HATS-56 b · Gas Giant

Host System: HATS-55

Spectral Class

F-type yellow-white

Effective Temperature

6,214 K — hotter than the Sun (5,778 K)

Estimated Age

0.40 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.126 R☉

Stellar Mass

1.196 M☉

Metallicity [Fe/H]

0.11

Extended Stellar Properties

Surface gravity (log g)

4.412 dex

Stellar density

1.179 g/cm³

Systemic radial velocity

-2.92 km/s

Rotational v·sin i

5.01 km/s

Metallicity ratio

[Fe/H]

Distance

609.84 parsec

Light-years 1,989.02 ly

V-band magnitude

13.53 mag

Voyager-speed travel 35,076,423 yr

Multi-band Host Photometry — 14 bands

Astrometric Data

Parallax

1.611 mas

Total Proper Motion

6.305 mas/yr

PM Right Ascension

-6.28 mas/yr

PM Declination

0.53 mas/yr

Galactic Cartesian (pc)

x = -0.346 · y = 0.767 · z = -0.541

Equatorial (J2000)

RA 114.28338° · Dec -32.75542°

Galactic ℓ, b

247.002° · -5.651°

Ecliptic λ, β

125.316° · -53.258°

HTM-20 index

-127933180