UPSA Object Registry
Registry · exoplanet

HR 8799 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
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 starHR 8799 · A5 V
DiscoveryImaging, 2008 · Gemini Observatory
Orbital period170,000 d
Semi-major axis68 au
Eccentricity—
Radius13 R⊕ · 1.2 R♃
Mass2,000 M⊕ · 7 M♃
Density5 g/cm³
Equilibrium temperature1,200 K
System distance41.244 pc

Recorded parameters

2 quantities with a single published value
ParameterValueUnitUncertainty As publishedSourceReference
Mass 2,000 M_earth ± 1,000 Imaging NASA Exoplanet Archive Marois et al. 2008
Equilibrium temperature 1,200 K Imaging NASA Exoplanet Archive Bonnefoy et al. 2016

Published measurements

3 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

ValueUnitUncertainty Band / methodSourceReferenceYear
6.7254 R_earth Imaging NASA Exoplanet Archive Bonnefoy et al. 2016 2016
13 R_earth ± 1 Imaging NASA Exoplanet Archive Marois et al. 2008 2008

Orbital period 3 values

ValueUnitUncertainty Band / methodSourceReferenceYear
166,510.2 d ± 9,022 Imaging NASA Exoplanet Archive Zurlo et al. 2016 2016
171,667.5 d Imaging NASA Exoplanet Archive Konopacky et al. 2016 2016
170,000 d Imaging NASA Exoplanet Archive Marois et al. 2008 2008

Semi-major axis 3 values

ValueUnitUncertainty Band / methodSourceReferenceYear
67.96 au ± 1.85 Imaging NASA Exoplanet Archive Zurlo et al. 2016 2016
70 au Imaging NASA Exoplanet Archive Konopacky et al. 2016 2016
68 au Imaging NASA Exoplanet Archive Marois et al. 2008 2008

In the same field

within 9 arcmin · wider search
ObjectTypeSeparationV
HR 8799 d Exoplanet 0″ 5.98
HR 8799 c Exoplanet 0″ 5.98
HR 8799 e 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
ArchiveRead at (UTC)Record
Seeded from the bulk archive load; no per-object fetch yet.

Machine-readable: /api/v1/object/hr-8799-b · Registry entry updated 2026-08-14.