Registry · exoplanet

AU Mic 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: 20h 45m 09.87s
Declination: −31° 20′ 32.8″
Galactic l, b: 12.653, -36.8
Magnitude V: 8.81
Distance: 9.7221 pc

Planet

NASA Exoplanet Archive, composite parameters

Host star	AU Mic · M1 V
Discovery	Transit, 2020 · Transiting Exoplanet Survey Satellite (TESS)
Orbital period	8.46345 d
Semi-major axis	0.07 au
Eccentricity	0.07
Radius	4.79 R⊕ · 0.4273 R♃
Mass	8.99 M⊕ · 0.02829 M♃
Density	0.49 g/cm³
Equilibrium temperature	554.8 K
System distance	9.7221 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 8 values

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
6.1	M_earth	± 2.5	Transit	NASA Exoplanet Archive	Donati et al. 2025	2025
8.99	M_earth	± 2.61	Transit	NASA Exoplanet Archive	Mallorquín et al. 2024	2024
10.2	M_earth	± 3.9	Transit	NASA Exoplanet Archive	Donati et al. 2023	2023
11.7	M_earth	± 5	Transit	NASA Exoplanet Archive	Zicher et al. 2022	2022
17	M_earth	± 5	Transit	NASA Exoplanet Archive	Martioli et al. 2021	2021
17.1	M_earth	± 4.7	Transit	NASA Exoplanet Archive	Klein et al. 2021	2021
20.12	M_earth	± 1.57	Transit	NASA Exoplanet Archive	Cale et al. 2021	2021
57.2094	M_earth		Transit	NASA Exoplanet Archive	Plavchan et al. 2020	2020

Radius 8 values

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
4.79	R_earth	± 0.29	Transit	NASA Exoplanet Archive	Mallorquín et al. 2024	2024
3.95677	R_earth	± 0.1457	Transit	NASA Exoplanet Archive	Wittrock et al. 2023	2023
3.55	R_earth	± 0.13	Transit	NASA Exoplanet Archive	Szabó et al. 2022	2022
4.19	R_earth	± 0.24	Transit	NASA Exoplanet Archive	Gilbert et al. 2022	2022
4.38	R_earth	± 0.05	Transit	NASA Exoplanet Archive	Szabó et al. 2021	2021
4.07	R_earth	± 0.17	Transit	NASA Exoplanet Archive	Martioli et al. 2021	2021
4.026926	R_earth	± 0.2119	Transit	NASA Exoplanet Archive	ExoFOP	2020
4.203375	R_earth	± 0.2018	Transit	NASA Exoplanet Archive	Plavchan et al. 2020	2020

Orbital period 13 values

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
8.463446	d		Transit	NASA Exoplanet Archive	Donati et al. 2025	2025
8.463446	d	± 5.00e-06	Transit	NASA Exoplanet Archive	Mallorquín et al. 2024	2024
8.463143	d		Transit	NASA Exoplanet Archive	Donati et al. 2023	2023
8.46308	d	± 6.00e-05	Transit	NASA Exoplanet Archive	Wittrock et al. 2023	2023
8.463	d	± 2.00e-06	Transit	NASA Exoplanet Archive	Zicher et al. 2022	2022
8.463	d	± 5.80e-06	Transit	NASA Exoplanet Archive	Gilbert et al. 2022	2022
8.462995	d	± 3.00e-06	Transit	NASA Exoplanet Archive	Szabó et al. 2021	2021
8.463	d	± 2.00e-06	Transit	NASA Exoplanet Archive	Martioli et al. 2021	2021
8.46321	d		Transit	NASA Exoplanet Archive	Klein et al. 2021	2021
8.462999	d		Transit	NASA Exoplanet Archive	Cale et al. 2021	2021
8.453678	d		Transit	NASA Exoplanet Archive	ExoFOP	2020
8.46321	d	± 4.00e-05	Transit	NASA Exoplanet Archive	Plavchan et al. 2020	2020

Show the remaining 1

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
8.46321	d		Transit	NASA Exoplanet Archive	Hirano et al. 2020	2020

Semi-major axis 8 values

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
0.07	au	± 0.006	Transit	NASA Exoplanet Archive	Mallorquín et al. 2024	2024
0.0649	au	± 0.0012	Transit	NASA Exoplanet Archive	Wittrock et al. 2023	2023
0.0654	au	± 0.0012	Transit	NASA Exoplanet Archive	Szabó et al. 2022	2022
0.0644	au	± 0.0056	Transit	NASA Exoplanet Archive	Gilbert et al. 2022	2022
0.0704	au	± 0.0006	Transit	NASA Exoplanet Archive	Szabó et al. 2021	2021
0.0645	au	± 0.0013	Transit	NASA Exoplanet Archive	Martioli et al. 2021	2021
0.0645	au	± 0.0013	Transit	NASA Exoplanet Archive	Cale et al. 2021	2021
0.066	au	± 0.007	Transit	NASA Exoplanet Archive	Plavchan et al. 2020	2020

Eccentricity 8 values

Value	Uncertainty	Band / method	Source	Reference	Year
0.07	± 0.09	Transit	NASA Exoplanet Archive	Mallorquín et al. 2024	2024
0.00577	± 0.00101	Transit	NASA Exoplanet Archive	Wittrock et al. 2023	2023
0.04	± 0.045	Transit	NASA Exoplanet Archive	Zicher et al. 2022	2022
0.12	± 0.16	Transit	NASA Exoplanet Archive	Gilbert et al. 2022	2022
0		Transit	NASA Exoplanet Archive	Martioli et al. 2021	2021
0.186	± 0.036	Transit	NASA Exoplanet Archive	Cale et al. 2021	2021
0.1	± 0.17	Transit	NASA Exoplanet Archive	Plavchan et al. 2020	2020
0		Transit	NASA Exoplanet Archive	Hirano et al. 2020	2020

Equilibrium temperature 4 values

Value	Unit	Uncertainty	Band / method	Source	Reference	Year
554.8	K	± 31.6	Transit	NASA Exoplanet Archive	Mallorquín et al. 2024	2024
600	K	± 17	Transit	NASA Exoplanet Archive	Wittrock et al. 2023	2023
593	K	± 21	Transit	NASA Exoplanet Archive	Martioli et al. 2021	2021
754.62	K		Transit	NASA Exoplanet Archive	ExoFOP	2020

In the same field

within 9 arcmin · wider search

Object	Type	Separation	V
AU Mic c	Exoplanet	0″	8.81
AU Mic d	Exoplanet	0″	8.81
AU Mic e	Exoplanet	0″	8.81
AU Mic	Star	0″	—
HD 197481c	Planet	7.083″	—
HD 197481b	Planet	7.083″	—
HD 197481d	Planet Candidate	7.083″	—
HD 197481	BYDraV*	7.083″	8.627
UCAC4 294-224020	HighPM*	433.3″	13.02

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/au-mic-b · Registry entry updated 2026-08-14.