Temperature
4504 K
4504 to 4750
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Stellar HostProfile
iot Dra
K2 III • 31.33 pc
Records
12
literature rows
Planets
2
system count
References
13
distinct source labels
HD: HD 137759HIP: HIP 75458TIC: TIC 165722603
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: Hill et al. 2021 • System source: TICv8
Mass
1.54 Msun
1.05 to 1.54
Radius
11.79 Rsun
11.79 to 12.88
Age
2.65 Gyr
single adopted value
Luminosity
1.72 log(Lsun)
1.72 to 1.82
Distance
31.33 pc
single adopted value
Spectral Type
K2 III
Multiple classifications reported
Planets
2
Stable across source rows
Scale Comparison
Radius against the Sun
Current adopted radius: 11.79 R☉ (circles scaled linearly by radius)
Sun
1.0 R☉ baseline
iot Dra
11.79 R☉
System Layout
Known planets
2 planets linked to this host
iot Dra and Its Two Known Worlds
iot Dra is a K2 III star 102 light-years from Earth. Its reported mass estimate is 1.54 solar masses, and its reported radius estimate is 11.8 solar radii. Both the mass and radius estimates are larger than the Sun's. The star's reported temperature of 4500 K is cooler than the Sun's, and its age is 2.65 billion years.
Two planets are known to orbit iot Dra. Both iot Dra b and iot Dra c were found by the radial velocity method, which measures the wobble a planet's gravity induces in its star's motion; repeated wobbles reveal the planet and its orbital period.
iot Dra b was discovered in 2002. Its minimum mass - a lower bound on a planet's true mass - is 3760 Earth masses, and its orbital period is 511 days. That minimum mass is larger than Earth's and roughly 11.8 times Jupiter's mass. Among the listed planets, iot Dra b has the shortest year by reported estimates.
iot Dra c was discovered in 2021. Its minimum mass is 4960 Earth masses, and its orbital period is 25000 days. That minimum mass is larger than Earth's and roughly 15.6 times Jupiter's mass. Among the listed planets, iot Dra c has the longest year by reported estimates.
Among the listed planets, iot Dra b has the smallest minimum mass, at 3760 Earth masses, while iot Dra c has the largest minimum mass, at 4960 Earth masses.
Provenance
Underlying measurements and references
Evidence Summary
Rows
12
Stellar refs
12
System refs
1
Distancestable
Parallaxstable
Temperaturedisputed
Massdisputed
Radiusdisputed
Agestable
Luminositydisputed
Surface Gravitydisputed
Metallicitydisputed
Spectral Typedisputed
| ST TEFF | ST MASS | ST RAD | ST AGE | ST LUM | ST SPECTYPE | SY DIST | Stellar Ref | System Ref |
|---|---|---|---|---|---|---|---|---|
| 4534.1 | — | — | — | — | — | 31.33 | TICv8 | TICv8 |
| — | — | — | — | — | K0 | 31.33 | Cannon & Pickering 1918 | TICv8 |
| 4530 | 1.05 | — | — | — | — | 31.33 | Frink et al. 2002 | TICv8 |
| — | — | — | — | — | K2 III | 31.33 | Gray et al. 2003 | TICv8 |
| 4750 | — | — | — | — | — | 31.33 | Santos et al. 2003 | TICv8 |
| 4628 | — | — | — | — | — | 31.33 | Maldonado et al. 2015 | TICv8 |
| — | 1.05 | 12.88 | — | — | — | 31.33 | Kane et al. 2010 | TICv8 |
| 4548 | 1.05 | — | — | — | — | 31.33 | Butler et al. 2006 | TICv8 |
| 4528 | 1.14 | — | — | — | — | 31.33 | Mortier et al. 2013 | TICv8 |
| — | — | — | — | — | K2 III | 31.33 | Garrison & Beattie 1998 | TICv8 |
| 4504 | 1.54 | 11.79 | 2.65 | 1.72 | K2 III | 31.33 | Hill et al. 2021 | TICv8 |
| 4642 | — | 12.57 | — | 1.82 | — | 31.33 | Gaia DR2 | TICv8 |