Registry · exoplanet

HR 8799 e

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: 23h 07m 28.84s
Declination: +21° 08′ 02.5″
Galactic l, b: 92.765, -35.58
Magnitude V: 5.98
Distance: 41.244 pc

Planet

NASA Exoplanet Archive, composite parameters

Host star	HR 8799 · A5 V
Discovery	Imaging, 2010 · W. M. Keck Observatory
Orbital period	20,815.6 d
Semi-major axis	16.4 au
Eccentricity	0.15
Radius	13.115 R⊕ · 1.17 R♃
Mass	3,178.3 M⊕ · 10 M♃
Density	7.74 g/cm³
Equilibrium temperature	1,150 K
System distance	41.244 pc

Recorded parameters

2 quantities with a single published value

Parameter	Value	Unit	Uncertainty	As published	Source	Reference
Mass	3,178.3	M_earth	± 2,225	Imaging	NASA Exoplanet Archive	Gravity Collaboration et al. 2019
Eccentricity	0.15		± 0.08	Imaging	NASA Exoplanet Archive	Gravity Collaboration et al. 2019

Published measurements

4 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.

Radius 2 values

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
13.11453	R_earth	± 1.457	Imaging	NASA Exoplanet Archive	Gravity Collaboration et al. 2019	2019
10.0881	R_earth		Imaging	NASA Exoplanet Archive	Bonnefoy et al. 2016	2016

Orbital period 2 values

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
20,815.6	d	± 1,129	Imaging	NASA Exoplanet Archive	Zurlo et al. 2016	2016
18,000	d		Imaging	NASA Exoplanet Archive	Marois et al. 2010	2010

Semi-major axis 3 values

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
16.4	au	± 2.1	Imaging	NASA Exoplanet Archive	Gravity Collaboration et al. 2019	2019
16.99	au	± 0.46	Imaging	NASA Exoplanet Archive	Zurlo et al. 2016	2016
14.5	au	± 0.5	Imaging	NASA Exoplanet Archive	Marois et al. 2010	2010

Equilibrium temperature 2 values

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
1,150	K	± 50	Imaging	NASA Exoplanet Archive	Gravity Collaboration et al. 2019	2019
1,300	K		Imaging	NASA Exoplanet Archive	Bonnefoy et al. 2016	2016

In the same field

within 9 arcmin · wider search

Object	Type	Separation	V
HR 8799 b	Exoplanet	0″	5.98
HR 8799 d	Exoplanet	0″	5.98
HR 8799 c	Exoplanet	0″	5.98
HR 8799	Star	0″	—
HD 218396c	Planet	1.849″	—
HD 218396e	Planet	1.849″	—
HD 218396b	Planet	1.849″	—
HD 218396	EllipVar	1.849″	5.953
HD 218396d	Planet	1.849″	—
HD 218396f	Planet Candidate	1.849″	—
SDSS J230751.89+210526.7	QSO	358.3″	—

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/hr-8799-e · Registry entry updated 2026-08-14.