LTT 1445

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[1]
Declination −16° 35′ 36.0312″[1]
Apparent magnitude (V) 11.22±0.02[2]
LTT 1445 BC
Right ascension 03h 01m 51.04s[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 (Rv)−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]
Distance22.387 ± 0.004 ly
(6.864 ± 0.001 pc)
Orbit[2]
PrimaryLTT 1445 B
CompanionLTT 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
Mass0.257±0.014 M☉[4] M☉
Radius0.271+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
Temperature3,337±150[2] K
Metallicity [Fe/H]−0.34±0.08[2] dex
B
Mass0.215±0.014[2] M☉
Radius0.236±0.027[2] R☉
C
Mass0.161±0.014[2] M☉
Radius0.197±0.027[2] R☉
Rotation1.4 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
SIMBADA,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]

  1. ^ a b c d e f Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  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).
  3. ^ Cite error: The named reference henry2018 was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference Pass2023 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Lavie2022 was invoked but never defined (see the help page).