Registry · exoplanet

HAT-P-2 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: 16h 20m 36.34s
Declination: +41° 02′ 52.7″
Galactic l, b: 65.021, 45.23
Magnitude V: 8.72
Distance: 127.77 pc

Planet

NASA Exoplanet Archive, composite parameters

Host star	HAT-P-2 · F8
Discovery	Transit, 2007 · HATNet
Orbital period	5.63352 d
Semi-major axis	0.06814 au
Eccentricity	0.5172
Radius	10.66 R⊕ · 0.951 R♃
Mass	2,866.8 M⊕ · 9.02 M♃
Density	7.29 g/cm³
Equilibrium temperature	1,540 K
System distance	127.77 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 11 values

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
2,866.812	M_earth	± 31.78	Transit	NASA Exoplanet Archive	de Beurs et al. 2023	2023
2,739.695	M_earth	± 54.03	Transit	NASA Exoplanet Archive	Ment et al. 2018	2018
3,632.797	M_earth	± 616.6	Transit	NASA Exoplanet Archive	Stassun et al. 2017	2017
2,765.121	M_earth	± 60.39	Transit	NASA Exoplanet Archive	Bonomo et al. 2017	2017
2,828.6	M_earth		Transit	NASA Exoplanet Archive	Salz et al. 2015	2015
3,175.122	M_earth	± 73.1	Transit	NASA Exoplanet Archive	Knutson et al. 2014	2014
2,888.95	M_earth	± 76.28	Transit	NASA Exoplanet Archive	Pal et al. 2010	2010
2,777.834	M_earth	± 85.81	Transit	NASA Exoplanet Archive	Southworth 2010	2010
2,771.478	M_earth	± 124	Transit	NASA Exoplanet Archive	Torres et al. 2008	2008
2,739.695	M_earth	± 124	Transit	NASA Exoplanet Archive	Loeillet et al. 2008	2008
2,873.183	M_earth	± 158.9	Transit	NASA Exoplanet Archive	Bakos et al. 2007	2007

Radius 9 values

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
13.4508	R_earth	± 0.8967	Transit	NASA Exoplanet Archive	Stassun et al. 2017	2017
12.96881	R_earth	± 0.8183	Transit	NASA Exoplanet Archive	Bonomo et al. 2017	2017
12.3	R_earth		Transit	NASA Exoplanet Archive	Salz et al. 2015	2015
12.969	R_earth	± 0.818	Transit	NASA Exoplanet Archive	Pal et al. 2010	2010
13.33871	R_earth	± 1.345	Transit	NASA Exoplanet Archive	Southworth 2010	2010
11.24263	R_earth	± 0.9416	Transit	NASA Exoplanet Archive	Torres et al. 2008	2008
10.65976	R_earth	± 0.4372	Transit	NASA Exoplanet Archive	Loeillet et al. 2008	2008
13.2583	R_earth	± 0.5194	Transit	NASA Exoplanet Archive	ExoFOP	2007
11.00724	R_earth	± 0.4259	Transit	NASA Exoplanet Archive	Bakos et al. 2007	2007

Orbital period 16 values

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
5.63347	d	± 6.30e-07	Transit	NASA Exoplanet Archive	de Beurs et al. 2023	2023
5.633468	d	± 6.10e-07	Transit	NASA Exoplanet Archive	Kokori et al. 2023	2023
5.633515	d	± 3.40e-06	Transit	NASA Exoplanet Archive	Patel & Espinoza 2022	2022
5.63347	d	± 6.40e-07	Transit	NASA Exoplanet Archive	Ivshina & Winn 2022	2022
5.633516	d	± 3.60e-06	Transit	NASA Exoplanet Archive	Ment et al. 2018	2018
5.63347	d	± 6.00e-06	Transit	NASA Exoplanet Archive	Stassun et al. 2017	2017
5.633468	d	± 1.30e-06	Transit	NASA Exoplanet Archive	de Wit et al. 2017	2017
5.633475	d	± 2.60e-06	Transit	NASA Exoplanet Archive	Bonomo et al. 2017	2017
5.633472	d		Transit	NASA Exoplanet Archive	Garai et al. 2017	2017
5.6	d		Transit	NASA Exoplanet Archive	Salz et al. 2015	2015
5.633473	d	± 6.10e-06	Transit	NASA Exoplanet Archive	Pal et al. 2010	2010
5.633473	d	± 6.10e-06	Transit	NASA Exoplanet Archive	Southworth 2010	2010

Show the remaining 4

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
5.63332	d		Transit	NASA Exoplanet Archive	Torres et al. 2008	2008
5.63341	d		Transit	NASA Exoplanet Archive	Loeillet et al. 2008	2008
5.633477	d	± 1.00e-06	Transit	NASA Exoplanet Archive	ExoFOP	2007
5.63341	d	± 0.00013	Transit	NASA Exoplanet Archive	Bakos et al. 2007	2007

Semi-major axis 8 values

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
0.06814	au	± 0.00051	Transit	NASA Exoplanet Archive	Ment et al. 2018	2018
0.0688	au	± 0.00065	Transit	NASA Exoplanet Archive	Bonomo et al. 2017	2017
0.068	au		Transit	NASA Exoplanet Archive	Salz et al. 2015	2015
0.06878	au	± 0.00068	Transit	NASA Exoplanet Archive	Pal et al. 2010	2010
0.0674	au	± 0.00081	Transit	NASA Exoplanet Archive	Southworth 2010	2010
0.0679	au	± 0.0015	Transit	NASA Exoplanet Archive	Torres et al. 2008	2008
0.0677	au	± 0.0011	Transit	NASA Exoplanet Archive	Loeillet et al. 2008	2008
0.0677	au	± 0.0014	Transit	NASA Exoplanet Archive	Bakos et al. 2007	2007

Eccentricity 12 values

Value	Uncertainty	Band / method	Source	Reference	Year
0.502	± 0.011	Transit	NASA Exoplanet Archive	de Beurs et al. 2023	2023
0.5171	± 0.0033	Transit	NASA Exoplanet Archive	Kokori et al. 2023	2023
0.5172	± 0.0019	Transit	NASA Exoplanet Archive	Ment et al. 2018	2018
0.52	± 0	Transit	NASA Exoplanet Archive	Stassun et al. 2017	2017
0.51023	± 0.00042	Transit	NASA Exoplanet Archive	de Wit et al. 2017	2017
0.50833	± 0.00082	Transit	NASA Exoplanet Archive	Bonomo et al. 2017	2017
0.51	± 0.016	Transit	NASA Exoplanet Archive	Garai et al. 2017	2017
0.5		Transit	NASA Exoplanet Archive	Salz et al. 2015	2015
0.5079	± 0.00093	Transit	NASA Exoplanet Archive	Knutson et al. 2014	2014
0.5171	± 0.0033	Transit	NASA Exoplanet Archive	Pal et al. 2010	2010
0.5163	± 0.0025	Transit	NASA Exoplanet Archive	Loeillet et al. 2008	2008
0.52	± 0.01	Transit	NASA Exoplanet Archive	Bakos et al. 2007	2007

Equilibrium temperature 5 values

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
1,700	K		Transit	NASA Exoplanet Archive	Salz et al. 2015	2015
1,540	K	± 30	Transit	NASA Exoplanet Archive	Pal et al. 2010	2010
1,516	K	± 66	Transit	NASA Exoplanet Archive	Southworth 2010	2010
1,398	K	± 61	Transit	NASA Exoplanet Archive	Torres et al. 2008	2008
1,372	K		Transit	NASA Exoplanet Archive	ExoFOP	2007

In the same field

within 9 arcmin · wider search

Object	Type	Separation	V
HAT-P-2 c	Exoplanet	0″	8.72
HAT-P-2	Star	0″	—
HD 147506	Star	0.4768″	8.69
HD 147506c	Planet	0.4768″	—
HD 147506b	Planet	0.4768″	—
2MASX J16203923+4058536	GtowardsCl	241.7″	—
SDSS J162043.25+410658.8	QSO	258.3″	—
BD+41 2695	HighPM*	362.5″	9
HD 147586	Star	367.5″	8.19
SDSS J162003.35+410245.3	QSO	373.3″	—
SDSS J162037.29+405505.2	QSO	467.5″	—

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/hat-p-2-b · Registry entry updated 2026-08-14.