Key parameters at a glance

A radius of 12.44 Earth radii
A mass of 8,654.15 Earth masses
Surface gravity around 55.90 g
An orbital period of 1.218 days
Semi-major axis 0.0247 AU
Equilibrium temperature 2,361 K (2088 °C)
Distance from Earth 875.50 light-years
Earth Similarity Index 0.044
Travel time at Voyager 1 speed 15,439,451 years

KELT-1 b Planet Profile

Physical Specs

Radius

12.44 R⊕

Radius (Jupiter)

1.110 R♃

Mass

8,654.15 M⊕

Mass (Jupiter)

27.230 M♃

Density

24.70 g/cm³

Surface Gravity

55.90 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.044

HZ Position Inner

Controversial No

Discovery

Year 2012

Method Transit

Facility KELT

Telescope Mamiya 645 80mm f/1.9

Size rank in cohort

Rank by radius

#1285of 1771

top 72.5%

This planet

12.44R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

KOI-217 b 12.44 R⊕ HR 2562 b 12.44 R⊕ WASP-11 b 12.44 R⊕

Metric	Earth	KELT-1 b	Jupiter
Radius (R⊕)	1.00	12.44	11.21
Mass (M⊕)	1.00	8,654.15	317.83
Density (g/cm³)	5.51	24.70	1.33
Surface Gravity (g)	1.00	55.90	2.53
Insolation (S⊕)	1.00	5,165.92	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	8,654.150 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 432549364

Gaia DR2

Gaia DR2 2881784280929695360

Gaia DR3

Gaia DR3 2881784280929695360

System

KELT-1

Percentile among Gas Giant cohort

Radius 12.442 R⊕ · percentile 27 / cohort 1771

Mass 8,654.150 M⊕ · percentile 99 / cohort 1747

Orbital period 1.22 d · percentile 1 / cohort 1533

Distance 268.43 pc · percentile 57 / cohort 1759

ESI 0.044 · percentile 2 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

1.218 days

Semi-major axis

0.0247 AU

Eccentricity

0.010

Inclination

87.80 °

Year Length

A year here lasts approximately 1.22 Earth days (0.3% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0247 AU.

Transit Fingerprint

Depth

0.609 %

Duration

2.765 h

Impact parameter b

0.232

Rp / R★

0.077100

Transit midpoint (BJD)

2,455,914.1628

Photometric dip

Transit produces a flux drop of 6,086 ppm lasting ≈ 2.76 h.

Extended Orbital Architecture

Planet / star radius ratio

0.077100

Semi-major axis / stellar radius

3.690

Impact parameter (b)

0.232

Occultation depth

0.142 ppm

Transit mid-time (BJD)

2,455,914.1628

Long. of periastron (ω)

61.00°

Sky-projected obliquity (λ)

2.00°

Angular separation (arcsec)

0.09190

Eq. Temperature

2,361K

(2088 °C)

Insolation (S⊕)

5,165.92

Earth = 1.00

Earth Similarity (ESI)

0.044

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

Siverd et al. 2012

Instrument

Apogee 4K CCD Sensor

Publication

2012-12

Observation locale

Ground

Host System: KELT-1

Spectral Class

F-type yellow-white

Effective Temperature

6,516 K — hotter than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

1.471 R☉

Stellar Mass

1.335 M☉

Metallicity [Fe/H]

0.05

Extended Stellar Properties

Surface gravity (log g)

4.228 dex

Stellar density

0.621 g/cm³

Systemic radial velocity

-14.20 km/s

Rotational v·sin i

56.00 km/s

Metallicity ratio

[Fe/H]

Distance

268.43 parsec

Light-years 875.50 ly

V-band magnitude

10.63 mag

Voyager-speed travel 15,439,451 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

3.697 mas

Total Proper Motion

12.428 mas/yr

PM Right Ascension

-9.77 mas/yr

PM Declination

-7.68 mas/yr

Galactic Cartesian (pc)

x = 0.773 · y = 0.005 · z = 0.635

Equatorial (J2000)

RA 0.36210° · Dec 39.38380°

Galactic ℓ, b

112.504° · -22.474°

Ecliptic λ, β

18.381° · 35.465°

HTM-20 index

-2137713505