Temperature
5520 K
4975.9 to 5522
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Stellar HostProfile
KOI-1257
G5 V
Records
12
literature rows
Planets
1
system count
References
13
distinct source labels
TIC: TIC 159647910
Approximate color
from effective temperature
Canonical Summary
Adopted host values from one source row
Values come from the row with the most populated summary measurements. Missing values stay missing. Ranges and counts describe all source rows.
Stellar source: Santerne et al. 2014 • System source: TICv8
Mass
0.99 Msun
0.78 to 0.99
Radius
1.13 Rsun
0.84 to 1.19
Age
9.30 Gyr
7.41 to 13.90
Spectral Type
G5 V
Consistent across records
Planets
1
Stable across source rows
Scale Comparison
Radius against the Sun
Current adopted radius: 1.13 R☉ (circles scaled linearly by radius)
Sun
1.0 R☉ baseline
KOI-1257
1.13 R☉
System Layout
Known planets
1 planets linked to this host
KOI-1257 b
Transit
◌
Discovery
2014
Period
86.65 days
Radius
10.54 R⊕
Mass
460.8 M⊕
Eq. Temp
511 K
KOI-1257 b: A Jupiter-Like World Orbiting a Sun-Like Star
KOI-1257 is a G-type main-sequence star, a Sun-like dwarf somewhat older and larger than the Sun. It has an age of 9.3 billion years, a mass of 0.99 solar masses, a radius of 1.13 solar radii, and a temperature of 5520 K, which is cooler than the Sun's. One planet is known to orbit this host.
That planet, KOI-1257 b, is a Jupiter-like world, a class defined by a radius exceeding 4 times Earth's. It was discovered in 2014 by the transit method, in which a planet passes in front of its star from our viewpoint and causes a small dip in observed brightness. Its radius is 10.5 Earth radii, larger than Earth's, and its mass is 461 Earth masses, also larger than Earth's and roughly 1.45 times Jupiter's mass. Its mean density is 2.17 g/cm³, 0.394 times Earth's. KOI-1257 b completes an orbit every 86.6 days.
Provenance
Underlying measurements and references
Evidence Summary
Rows
12
Stellar refs
12
System refs
1
Temperaturedisputed
Massdisputed
Radiusdisputed
Agedisputed
Surface Gravitydisputed
Metallicitydisputed
Spectral Typestable
| ST TEFF | ST MASS | ST RAD | ST AGE | ST LUM | ST SPECTYPE | SY DIST | Stellar Ref | System Ref |
|---|---|---|---|---|---|---|---|---|
| 5520 | 0.99 | 1.13 | 9.30 | — | G5 V | — | Santerne et al. 2014 | TICv8 |
| 5142 | — | 1.19 | — | — | — | — | Latham et al. 2005 | TICv8 |
| 5142 | — | 0.84 | — | — | — | — | Q1-Q6 KOI Table | TICv8 |
| 5522 | 0.96 | 1.12 | — | — | — | — | Q1-Q17 DR25 KOI Table | TICv8 |
| 5321 | 0.78 | 0.86 | — | — | — | — | Q1-Q12 KOI Table | TICv8 |
| 5321 | 0.78 | 0.86 | — | — | — | — | Q1-Q16 KOI Table | TICv8 |
| 5321 | 0.78 | 0.86 | — | — | — | — | Q1-Q17 DR24 KOI Table | TICv8 |
| — | — | — | — | — | — | — | Q1-Q17 DR25 Supplemental KOI Table | TICv8 |
| 5421 | 0.89 | 0.89 | 7.41 | — | — | — | Morton et al. 2016 | TICv8 |
| 5311 | 0.80 | 0.85 | 13.90 | — | — | — | Q1-Q8 KOI Table | TICv8 |
| 5142 | — | 0.84 | — | — | — | — | Batalha et al. 2013 | TICv8 |
| 4975.9 | — | — | — | — | — | — | Gaia DR2 | TICv8 |