Registry · exoplanet

XO-3 b

Exoplanet

harvesting The full record is being pulled from the archives right now — measurement tables, the Gaia row, catalogue photometry. This page will fill itself in.

Right ascension: 04h 21m 52.70s
Declination: +57° 49′ 02.0″
Galactic l, b: 148.1, 5.628
Magnitude V: 9.854
Distance: 213.05 pc

Planet

NASA Exoplanet Archive, composite parameters

Host star	XO-3 · F5V
Discovery	Transit, 2007 · XO
Orbital period	3.19152 d
Semi-major axis	0.04815 au
Eccentricity	0.2791
Radius	14.796 R⊕ · 1.32 R♃
Mass	4,217.6 M⊕ · 13.27 M♃
Density	7.16 g/cm³
Equilibrium temperature	1,890 K
System distance	213.05 pc

Published measurements

6 quantities measured more than once

One object can carry a dozen published estimates of the same quantity. The register keeps them side by side rather than picking a winner — the citation is part of the value.

Mass 7 values

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
4,217.583	M_earth	± 111.2	Transit	NASA Exoplanet Archive	Rusznak et al. 2025	2025
2,316.981	M_earth	± 378.2	Transit	NASA Exoplanet Archive	Stassun et al. 2017	2017
3,718.611	M_earth	± 133.5	Transit	NASA Exoplanet Archive	Bonomo et al. 2017	2017
3,861.635	M_earth	± 152.6	Transit	NASA Exoplanet Archive	Knutson et al. 2014	2014
3,759.929	M_earth	± 124	Transit	NASA Exoplanet Archive	Southworth 2010	2010
4,211.226	M_earth	± 203.4	Transit	NASA Exoplanet Archive	Johns-Krull et al. 2008	2008
3,747.06	M_earth	± 187.5	Transit	NASA Exoplanet Archive	Winn et al. 2008	2008

Radius 7 values

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
14.79585	R_earth	± 0.2802	Transit	NASA Exoplanet Archive	Rusznak et al. 2025	2025
15.80469	R_earth	± 1.345	Transit	NASA Exoplanet Archive	Stassun et al. 2017	2017
13.64135	R_earth	± 0.8183	Transit	NASA Exoplanet Archive	Bonomo et al. 2017	2017
13.98883	R_earth	± 0.5492	Transit	NASA Exoplanet Archive	Southworth 2010	2010
21.85751	R_earth	± 1.793	Transit	NASA Exoplanet Archive	Johns-Krull et al. 2008	2008
13.641	R_earth	± 0.818	Transit	NASA Exoplanet Archive	Winn et al. 2008	2008
16.4091	R_earth	± 1.636	Transit	NASA Exoplanet Archive	ExoFOP	2007

Orbital period 14 values

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
3.191523	d	± 1.36e-07	Transit	NASA Exoplanet Archive	Sodickson & Grunblatt 2025	2025
3.191523	d	± 1.40e-07	Transit	NASA Exoplanet Archive	Rusznak et al. 2025	2025
3.191524	d	± 2.00e-07	Transit	NASA Exoplanet Archive	Kokori et al. 2023	2023
3.191525	d	± 3.00e-07	Transit	NASA Exoplanet Archive	Kokori et al. 2022	2022
3.191561	d	± 7.80e-05	Transit	NASA Exoplanet Archive	Patel & Espinoza 2022	2022
3.191524	d	± 1.00e-06	Transit	NASA Exoplanet Archive	Ivshina & Winn 2022	2022
3.19154	d	± 0.00014	Transit	NASA Exoplanet Archive	Stassun et al. 2017	2017
3.191533	d	± 5.80e-07	Transit	NASA Exoplanet Archive	Bonomo et al. 2017	2017
3.191523	d		Transit	NASA Exoplanet Archive	Garai et al. 2017	2017
3.191532	d	± 5.50e-07	Transit	NASA Exoplanet Archive	Wong et al. 2014	2014
3.191529	d	± 3.20e-06	Transit	NASA Exoplanet Archive	Southworth 2010	2010
3.191543	d	± 0.00014	Transit	NASA Exoplanet Archive	Johns-Krull et al. 2008	2008

Show the remaining 2

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
3.191524	d	± 6.80e-06	Transit	NASA Exoplanet Archive	Winn et al. 2008	2008
3.191526	d	± 2.40e-06	Transit	NASA Exoplanet Archive	ExoFOP	2007

Semi-major axis 5 values

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
0.04815	au	± 0.00061	Transit	NASA Exoplanet Archive	Rusznak et al. 2025	2025
0.04539	au	± 0.00081	Transit	NASA Exoplanet Archive	Bonomo et al. 2017	2017
0.04529	au	± 0.00073	Transit	NASA Exoplanet Archive	Southworth 2010	2010
0.0476	au	± 0.0005	Transit	NASA Exoplanet Archive	Johns-Krull et al. 2008	2008
0.0454	au	± 0.00082	Transit	NASA Exoplanet Archive	Winn et al. 2008	2008

Eccentricity 9 values

Value	Uncertainty	Band / method	Source	Reference	Year
0.2791	± 0.0024	Transit	NASA Exoplanet Archive	Rusznak et al. 2025	2025
0.2769	± 0.0017	Transit	NASA Exoplanet Archive	Kokori et al. 2023	2023
0.29	± 0	Transit	NASA Exoplanet Archive	Stassun et al. 2017	2017
0.27587	± 0.00071	Transit	NASA Exoplanet Archive	Bonomo et al. 2017	2017
0.285	± 0.003	Transit	NASA Exoplanet Archive	Garai et al. 2017	2017
0.2833	± 0.0034	Transit	NASA Exoplanet Archive	Knutson et al. 2014	2014
0.2769	± 0.0017	Transit	NASA Exoplanet Archive	Wong et al. 2014	2014
0.26	± 0.017	Transit	NASA Exoplanet Archive	Johns-Krull et al. 2008	2008
0.26	± 0.017	Transit	NASA Exoplanet Archive	Winn et al. 2008	2008

Equilibrium temperature 3 values

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
1,890	K	± 32	Transit	NASA Exoplanet Archive	Rusznak et al. 2025	2025
1,729	K	± 34	Transit	NASA Exoplanet Archive	Southworth 2010	2010
1,626	K		Transit	NASA Exoplanet Archive	ExoFOP	2007

In the same field

within 9 arcmin · wider search

Object	Type	Separation	V
XO-3	Star	0.004347″	—
BD+57 793b	Planet	0.07751″	—
BD+57 793	Star	0.07751″	9.85
HD 237249	PulsV*	303.2″	8.79
HD 237246	Star	424.4″	9.21

Provenance

where this card came from

Archive	Read at (UTC)	Record
Seeded from the bulk archive load; no per-object fetch yet.

Machine-readable: /api/v1/object/xo-3-b · Registry entry updated 2026-08-14.