LTT 1445 information

LTT 1445 A,BC
	; Hubble ACS/HRC image showing all three stars. Upper left is LTT 1445 A and in the lower right part of the image is the LTT 1445 BC pair.
Observation data; Epoch J2000.0 Equinox J2000.0
Constellation	Eridanus
	LTT 1445 A
Right ascension	03h 01m 51.39367s
Declination	−16° 35′ 36.0312″
Apparent magnitude (V)	11.22±0.02
	LTT 1445 BC
Right ascension	03h 01m 51.04s
Declination	−16° 35′ 31.1″
Apparent magnitude (V)	11.37±0.03
Characteristics
Spectral type	M2.5+M3.0+M
Astrometry
LTT 1445 A
Radial velocity (Rv)	−5.74±0.33 km/s
Proper motion (μ)	RA: −369.972 mas/yr ; Dec.: −267.931 mas/yr
Parallax (π)	145.6922 ± 0.0244 mas
Distance	22.387 ± 0.004 ly ; (6.864 ± 0.001 pc)
Orbit
Primary	LTT 1445 B
Companion	LTT 1445 C
Period (P)	36.2±5.3 yr
Semi-major axis (a)	1.159±0.076″
Eccentricity (e)	0.50±0.11
Inclination (i)	89.64±0.13°
Longitude of the node (Ω)	137.63±0.19°
Periastron epoch (T)	2019.2±1.7
Argument of periastron (ω); (secondary)	209±13°
Details
A
Mass	0.257±0.014 M☉ M☉
Radius	0.271+0.019; −0.010 R☉ R☉
Luminosity (bolometric)	0.00805±0.00035 L☉
Surface gravity (log g)	4.967+0.061; −0.075 cgs
Temperature	3,337±150 K
Metallicity [Fe/H]	−0.34±0.08 dex
B
Mass	0.215±0.014 M☉
Radius	0.236±0.027 R☉
C
Mass	0.161±0.014 M☉
Radius	0.197±0.027 R☉
Rotation	1.4 d
Other designations
	BD−17 588, HIP 14101, WDS J03019-1633A,BC, IRAS 02595-1647, 2MASS J03015142-1635356, 2MASS J03015107-1635306, TIC 98796344, TOI-455, GJ 3192, GJ 3193
Database references
SIMBAD	A,BC

LTT 1445 is a triple M-dwarf system 22.4 light-years (6.9 parsecs) distant^[1] in the constellation Eridanus. The primary LTT 1445 A hosts two exoplanets—one discovered in 2019 that transits the star every 5.36 days, and another found in 2021 that transits the star every 3.12 days, close to a 12:7 resonance. As of October 2022 it is the second closest transiting exoplanet system discovered, with the closest being HD 219134 bc.^[5]

^ ^a ^b ^c ^d ^e ^f Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ Cite error: The named reference Winters et al was invoked but never defined (see the help page).
^ Cite error: The named reference henry2018 was invoked but never defined (see the help page).
^ ^a ^b ^c Cite error: The named reference Pass2023 was invoked but never defined (see the help page).
^ Cite error: The named reference Lavie2022 was invoked but never defined (see the help page).

[GaiaDR3-1] ^ ^a ^b ^c ^d ^e ^f Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).

[Winters_et_al-2] ^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ Cite error: The named reference Winters et al was invoked but never defined (see the help page).

[henry2018-3] Cite error: The named reference henry2018 was invoked but never defined (see the help page).

[Pass2023-4] Cite error: The named reference Pass2023 was invoked but never defined (see the help page).

[Lavie2022-5] Cite error: The named reference Lavie2022 was invoked but never defined (see the help page).

Observation data Epoch J2000.0 Equinox J2000.0
Hubble ACS/HRC image showing all three stars. Upper left is LTT 1445 A and in the lower right part of the image is the LTT 1445 BC pair.
Constellation	Eridanus
LTT 1445 A
Right ascension	03^h 01^m 51.39367^s^[1]
Declination	−16° 35′ 36.0312″^[1]
Apparent magnitude (V)	11.22±0.02^[2]
LTT 1445 BC
Right ascension	03^h 01^m 51.04^s^[2]
Declination	−16° 35′ 31.1″^[2]
Apparent magnitude (V)	11.37±0.03^[2]
Characteristics
Spectral type	M2.5+M3.0+M^[3]^[2]
Astrometry
LTT 1445 A
Radial velocity (R_v)	−5.74±0.33^[1] km/s
Proper motion (μ)	RA: −369.972 mas/yr^[1] Dec.: −267.931 mas/yr^[1]
Parallax (π)	145.6922 ± 0.0244 mas^[1]
Distance	22.387 ± 0.004 ly (6.864 ± 0.001 pc)

Orbit^[2]
Primary	LTT 1445 B
Companion	LTT 1445 C
Period (P)	36.2±5.3 yr
Semi-major axis (a)	1.159±0.076″
Eccentricity (e)	0.50±0.11
Inclination (i)	89.64±0.13°
Longitude of the node (Ω)	137.63±0.19°
Periastron epoch (T)	2019.2±1.7
Argument of periastron (ω) (secondary)	209±13°
Details
A
Mass	0.257±0.014 M_☉^[4] `M`_☉
Radius	0.271+0.019 −0.010 R_☉^[4] `R`_☉
Luminosity (bolometric)	0.00805±0.00035^[2] `L`_☉
Surface gravity (log g)	4.967+0.061 −0.075^[2] cgs
Temperature	3,337±150^[2] K
Metallicity [Fe/H]	−0.34±0.08^[2] dex
B
Mass	0.215±0.014^[2] `M`_☉
Radius	0.236±0.027^[2] `R`_☉

C
Mass	0.161±0.014^[2] `M`_☉
Radius	0.197±0.027^[2] `R`_☉
Rotation	1.4 d^[4]

Other designations
BD−17 588, HIP 14101, WDS J03019-1633A,BC, IRAS 02595-1647, 2MASS J03015142-1635356, 2MASS J03015107-1635306, TIC 98796344, TOI-455, GJ 3192, GJ 3193
Database references
SIMBAD	A,BC

LTT 1445 information

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Gamma Eridani

Tau2 Eridani

Omicron1 Eridani

Upsilon2 Eridani

HD 260655

51 Eridani

2019 BE5

Zeta Eridani

Tau4 Eridani

Tau3 Eridani

Tau6 Eridani

Mu Eridani

Upsilon3 Eridani

Lambda Eridani

Tau9 Eridani

Pi Eridani

Psi Eridani

Rho2 Eridani

Tau8 Eridani

Omega Eridani

Upsilon1 Eridani

Phi Eridani

Kappa Eridani