GJ 3323

GJ 3323 (also known as LHS 1723) is a nearby single^[7] star located in the equatorial constellation Eridanus, about 0.4° to the northwest of the naked eye star Psi Eridani.^[8] It is invisible to the naked eye with an apparent visual magnitude 12.20.^[2] Parallax measurements give a distance estimate of 17.5 light-years (5.4 parsecs) from the Sun.^[1] It is drifting further away with a radial velocity of +42.3 km/s.^[2] Roughly 104,000 years ago, the star is believed to have come to within 7.34 ± 0.16 light-years of the Solar System.^[9]

GJ 3323

GJ 3323 Location of GJ 3323 in the constellation Eridanus
Observation data Epoch J2000      Equinox J2000
Constellation	Eridanus
Right ascension	05h 01m 57.42613s[1]
Declination	−06° 56′ 46.3763″[1]
Apparent magnitude (V)	12.20[2]
Characteristics
Spectral type	M4.0Ve[3]
B−V color index	+1.72[2]
Astrometry
Radial velocity (Rv)	42.309±0.0809[2] km/s
Proper motion (μ)	RA: −551.746 mas/yr[1] Dec.: −533.648 mas/yr[1]
Parallax (π)	186.0466±0.0277 mas[1]
Distance	17.531 ± 0.003 ly (5.3750 ± 0.0008 pc)
Absolute magnitude (MV)	13.57[3]
Details[4]
Mass	0.1705±0.0044 M☉
Radius	0.1862±0.0059 R☉
Luminosity	0.003654±0.000052 L☉
Surface gravity (log g)	5.07±0.07 cgs
Temperature	3,288±51 K
Metallicity [Fe/H]	+0.01±0.16 dex
Rotation	88.50 d[5]
Rotational velocity (v sin i)	1.0±0.8[3] km/s
Other designations
GJ 3323, LHS 1723, NLTT 14393, 2MASS J05015746-0656459[6]
Database references
SIMBAD	data
Exoplanet Archive	data

The stellar classification of GJ 3323 is M4.0Ve,^[3] indicating that it is a red dwarf, with emission lines appearing in its spectrum.^[2] It is fully convective and a source of X-ray emission.^[5] The star has 17% of the Sun's mass, 19% of the radius of the Sun, and just 0.4% of the Sun's luminosity.^[4]

History of observations

The discovery name of this star is LP 656-38,^[10] which indicates that its discovery was published between 1963 and 1981 in University of Minnesota, Minneapolis.^[11] "LP" means "Luyten, Palomar".

GJ 3323 is known at least from 1979, when catalogues of high proper motion objects LHS and NLTT were published by Willem Jacob Luyten, and this object was included to these catalogues.^[12][13]

Distance measurement

In 1982, Wilhelm Gliese published a photometric distance of GJ 3323 (161 mas),^[14] and in 1991 it was included in the 3rd preliminary version of catalogue of nearby stars by Gliese and Jahreiss as NN 3323 (also designated as GJ 3323) with photometric parallax 163.0±26.0 mas.^[15]

Its trigonometric parallax remained unknown until 2006, when it was published by the RECONS team. The parallax was 187.92±1.26 mas.^[16]

Planetary system

On March 15, 2017, two planets orbiting GJ 3323 were detected by the HARPS telescope, although the discovery team considers GJ 3323 c a planet candidate.^[7] The inner planet, GJ 3323 b, may orbit within the circumstellar habitable zone of its star.^[17]

The GJ 3323 planetary system^[7]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	≥2.02+0.26 −0.25 M🜨	0.03282+0.00054 −0.00056	5.3636±0.0007	0.23±0.11	—	—
c	≥2.31+0.50 −0.49 M🜨	0.1264+0.0021 −0.0022	40.54+0.21 −0.19	0.17+0.21 −0.12	—	—

Artist's impression and size comparison of the two known planets in the GJ 3323 system with Earth, assuming Earth-like composition