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K2-121 Overview

  • Star: K2-121
    • Stellar Radius: 0.68 Solar Radius
    • Stellar Effective Temperature: 4526.00 K
    • Planet: K2-121 b
      • Disposition Confirmed
      • Planet Radius 0.639 Jupiter Radius

K2-121 Architecture & Discovery Information

Name Orbital Separation Planet Size Method Year Reference Disposition
K2-121
K2-121 b 5.19 d 7.16 R⨁ Transit 2017 Dressing et al. 2017 Confirmed Planet
RA
08h27m44.80s
Dec
+17d34m45.58s
Distance
169.398+1.061-1.048
pc
Parallax
5.8746200±0.0364652 mas
Ecliptic Latitude
-1.48939 deg
Ecliptic Longitude
124.96014 deg
Galactic Latitude
28.93705 deg
Galactic Longitude
206.93309 deg
Total Proper Motion
20.2195641±0.0515579 mas/yr
Proper Motion (RA)
-13.8705000±0.0620806 mas/yr
Proper Motion (Dec)
-14.7119000±0.0399412 mas/yr
Photometry
mV 13.229±0.080
mTESS 12.2440±0.0069
mJ 11.309±0.022
mH 10.742±0.022
mKs 10.616±0.018
mKep 12.935
mW1 10.549±0.023
mW2 10.612±0.019
mW3 10.533±0.100
mW4 8.299
mGaia 12.924700±0.000557
mB 14.360±0.057
mg 14.4538000±0.0028277
mi 12.611800±0.001661
mr 12.9405000±0.0010553
mu 16.6768000±0.0108005
mz 13.8626000±0.0100862
Abundances
(Hypatia Catalog)
[Fe/H] -0.15±0.04 dex
[Mg/H] -0.08±0.07 dex
Mission
K2: Observed in Campaigns 5, 18
Tools
Planetary Systems
ExoFOP Target Overview Page
IRSA Finding Chart
TOI
K2 Names
K2 Planets and Candidates
K2 Targets
Stellar Hosts
K2 Time Series
Source Howard et al. 2025 Castro-González et al. 2022 TICv8 Livingston et al. 2018 Gaia DR2 Mayo et al. 2018 Dressing et al. 2017 Kruse et al. 2019 Petigura et al. 2018 ExoFOP Pope et al. 2016 Barros et al. 2016
Teff
(K)
4526.0±110.0
4690+43-41
4664.800+162.320-126.257
 4551±74
4680.445+192.490-130.422
 4695.0±50.0
4471.383789+111.559784-103.571655
 --- --- 4664.8±144.3 --- ---
Metallicity
(dex)
0.040±0.080 [Fe/H]
-0.16+0.05-0.06
[Fe/H] 		0.1107230±0.0130056 [M/H] -0.040±0.100 [Fe/H] --- -0.14±0.08 [Fe/H] --- --- --- --- --- ---
M✶
(M⦿)
0.71±0.03 0.69±0.03
0.7400000+0.0851151-0.0960964
 0.72±0.01 ---
0.727090 +0.024924-0.023943
0.711514±0.071151 --- --- --- --- ---
R✶
(R⦿)
0.675±0.033 0.67±0.01
0.6491270+0.0666206-0.0436407
 0.68±0.01
0.6370468+0.0370439-0.0493351
0.686484 +0.020318-0.021136
0.768000+0.042176-0.041929
0.637 +0.049-0.037
0.71 0.65±0.06 --- ---
S Index
0.728 --- --- --- --- --- --- --- --- --- --- ---
CAII LOG RHK
-4.534 --- --- --- --- --- --- --- --- --- --- ---
log g
(log10(cm/s2))
4.63±0.20 4.63±0.02
4.682640+0.113214-0.101010
 4.63±0.01 --- 4.68±0.1 --- --- --- 4.68±0.11 --- ---
L✶
(log10(L⦿))
--- ---
-0.7453137+0.0243100-0.0201599
 ---
-0.75581403+0.00481670-0.00487072
 --- --- --- --- --- --- ---
γ
(km/s)
--- --- --- --- 30.154180291337227±1.155569854560835 --- --- --- --- --- --- ---
ρ✶
(g/cm3)
--- ---
3.8142428+1.5888601-0.9003842
6.532+0.658-0.620
 --- --- --- --- --- --- --- ---
Print
Status
Confirmed Planet
Detected By
Radial Velocity, Transit
Tools
Planetary Systems
Transit Prediction Service
TOI
K2 Names
K2 Planets and Candidates
Transit
Source Howard et al. 2025 Kokori et al. 2023 Castro-González et al. 2022 Livingston et al. 2018 Mayo et al. 2018 Dressing et al. 2017 Kruse et al. 2019 Petigura et al. 2018 ExoFOP Barros et al. 2016 Pope et al. 2016
a/R✶
---
14.46+0.16-0.12
20.19+1.04-1.35
21.02+0.42-1.12
20.133408 +0.898387-1.261031
14.71+0.83-0.82
17.69 +0.82-1.05
--- --- --- ---
S
(S⨁)
62.5+9.6-8.5
 --- --- --- ---
89.50+12.50-11.20
 --- --- 126.877 --- ---
ω
(deg)
---
73.00+64.90-104.50
 --- --- ---
72.9700000+64.8569140-104.5056780
 --- --- --- --- ---
e
---
0.22+0.19-0.18
 --- --- ---
0.220000+0.194341-0.183890
 --- --- --- --- ---
i
(deg)
---
87.2+0.9-0.5
 --- ---
89.026588 +0.567715-0.537573
87.25+0.91-0.45
 --- --- --- --- ---
P
(days)
5.185738±0.000014 5.18575320±0.00000083
5.1857539+0.0000006-0.0000005
5.185761+0.000029-0.000030
 5.185759±0.000014
5.185754+0.000195-0.000201
 5.185758±0.000010
5.185743 +0.000027-0.000028
5.1857680±0.0000164 5.18597200 5.186
Rp
(R⨁)
7.16+0.12-0.06
 ---
7.52+0.22-0.18
 7.50±0.14
7.64369371272 +0.373225947414-0.291368307029
9.12+0.66-0.68
7.44 +0.62-0.50
7.7±1.1 7.503990±0.660588 --- ---
Rp
(RJup)
0.639+0.011-0.005
 ---
0.671+0.020-0.016
 0.669±0.012
0.6819246777 +0.0332969888-0.0259941393
0.814+0.059-0.061
0.664 +0.055-0.04
 0.69±0.10 0.6694623±0.0589338 --- ---
Rp/R✶
--- 0.109±0.005
0.1028+0.0027-0.0019
0.1009+0.0020-0.0009
0.102080 +0.003964-0.002294
0.108881+0.005142-0.005455
0.1070 +0.0032-0.0036
0.1005 +0.0013-0.0005
--- --- 0.103821
a
(au)
--- ---
0.0629+0.0033-0.0043
 0.0525±0.0003 --- 0.052±0.002 --- --- --- --- ---
TC
(days)
2457143.5607±0.0001
(BJD)
2458092.553641±0.000087
(BJD-TDB)
2457143.5605812+0.0000785-0.0000763
(BJD)
2457143.56042+0.00022-0.00021
(BJD)
2457143.56048 +0.000096-0.000101
2457143.561±0.001
(BJD)
2457143.56048 +0.000077-0.000078
(BJD)
2457143.56054 +0.000203-0.000205
(BJD)
2460255.0170050±0.0081182
(BJD)
2457143.560971
(BJD)
2457143.561
(BJD)
Teq
(K)
716.0±26.0 ---
738+7-19
 723±13 --- --- --- --- 935 --- ---
b
--- ---
0.34+0.15-0.22
0.21+0.17-0.15
 --- --- ---
0.14 +0.14-0.10
--- --- 0.133
δ
(%)
--- --- --- --- --- ---
1.3112 +0.0047-0.0045
--- 1.300200±0.051158 1.263±0.009 1.0779
T14
(hours)
--- --- --- --- --- ---
2.12640+0.02400-0.02160
2.03040+0.00960-0.00960
 2.356±0.166
2.14800+0.02700-0.02700
 1.77792
Mp
(M⨁)
51.0±11.0 --- --- --- --- --- --- --- --- --- ---
Mp
(MJup)
0.160±0.035 --- --- --- --- --- --- --- --- --- ---
ρ
(g/cm3)
0.7±0.2 --- --- --- --- --- --- --- --- --- ---
Print
Known Objects
1 Confirmed Planets
2 K2 Targets
2 2MASS Point Source Catalog
Data Files
1 KELT Praesepe Time Series
1 K2 Time Series
1 Associated Literature Data
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