HD 135344

HD 135344 is a young binary star system about 440 light-years away from Earth in the constellation Lupus. The primary star hosts a directly imaged gas giant planet, while the secondary star, also known as SAO 206462, is surrounded by a circumstellar disk of gas with clearly defined spiral arms and has three planet candidates.

HD 135344

The orbit of HD 135344 Ab around HD 135344 A (blocked by a coronagraph, position marked by star symbol) Credit: Stolker et al
Observation data Epoch J2000      Equinox J2000
Constellation	Lupus[1]
A
Right ascension	15h 15m 48.9463s[2]
Declination	−37° 08′ 55.731″[2]
Apparent magnitude (V)	7.76[3]
B
Right ascension	15h 15m 48.4460s[4]
Declination	−37° 09′ 16.024″[4]
Apparent magnitude (V)	8.708[5]
Characteristics
A
Evolutionary stage	main sequence[6]
Spectral type	A0V[3]
B
Evolutionary stage	main sequence[4]
Spectral type	F8V[5]
Astrometry
A
Radial velocity (Rv)	29.31±3.29[2] km/s
Proper motion (μ)	RA: −18.738 mas/yr[2] Dec.: −24.008 mas/yr[2]
Parallax (π)	7.4105±0.0403 mas[2]
Distance	440 ± 2 ly (134.9 ± 0.7 pc)
B
Radial velocity (Rv)	−5.34±1.48[4] km/s
Proper motion (μ)	RA: −19.210 mas/yr[4] Dec.: −23.268 mas/yr[4]
Parallax (π)	7.4074±0.0240 mas[4]
Distance	440 ± 1 ly (135.0 ± 0.4 pc)
Details
A
Mass	2.32[7] M☉
Radius	1.50±0.01[6] R☉
Luminosity	16.6±0.4[6] L☉
Surface gravity (log g)	4.1±0.1[6] cgs
Temperature	9540±100[6] K
Metallicity [Fe/H]	0.10[8] dex
B
Mass	1.5[4] M☉
Radius	2.1[4] R☉
Luminosity	6.4[4] L☉
Surface gravity (log g)	3.80[4] cgs
Temperature	6,313[4] K
Age	10.5[9] Myr
Other designations
CD−36 10010, HD 135344[3]
A: CPD−36 6758, SAO 206463, TYC 7324-1671-1[3]
B: CPD−36 6759, SAO 206462, TYC 7324-1676-1[5]
Database references
SIMBAD	A
	B

HD 135344 A

HD 135344 A is an A-type main-sequence star. It hosts a directly imaged gas giant planet, about 10 times the mass of Jupiter, discovered in 2025 with VLT/SPHERE.^[6]

The HD 135344 A planetary system^[6]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (years)	Eccentricity	Inclination	Radius
b	10.0+1.4 −1.9 MJ	16.5+2.8 −2.0	—	0.5±0.2	73.6+2.8 −4.7°	1.45+0.06 −0.03 RJ

HD 135344 B

The disk around HD 135344B (SAO 206462) imaged by VLT/SPHERE

The protoplanetary disk of HD 135344B as seen by the ERIS instrument of the VLT with the position of a potential forming exoplanet indicated.

HD 135344 B, also known as SAO 206462, has been known to have a circumstellar disk since the 1990s, first detected based on an infrared excess.^[10] Observations of the structure of the disk were presented in July 2009 by Carol Grady, astronomer of Eureka Scientific, headquartered in the Goddard Space Flight Center at NASA. It was the first of this class that exhibited a high degree of clarity and was observed using several space telescopes (Hubble, FUSE, Spitzer) and ground-based telescopes (Gemini Observatory and Subaru Telescope, situated in Hawaii), through an international research program of young stars and of stars with planets. A number of astronomers of different observatories collaborated.^[11] The disk's diameter is about twice the size of the orbit of Pluto.^[12]

The pair of spiral arms around SAO 206462 have a rotation rate of −0.85 degrees per year, which are thought to be caused by a dynamically driving protoplanet within the disk, at a distance of 66±3 astronomical units and an orbital period of 424±25 years. This planet should be a challenge to be detected using direct imaging due to the presence of dust particles obscuring it, but could be detected and confirmed via high-resolution spectroscopic observations.^[13]

Another planet candidate around SAO 206462 has been detected using observations of the JWST's NIRCam imaging instrument, with low signal-to-noise ratio, a mass of 0.8±0.3 M_J and a separation of 300 astronomical units. It has been dubbed CC1 (Companion candidate 1). Objects more massive than 2.2 M_J at distances of up to 120 AU have been ruled out by the observations.^[14]

A third planet candidate was detected by direct imaging in 2025, at the root of one of the disk's spiral arms. The object has a mass estimated at 2 M_J, and is highly embedded in gas and dust, possibly having its own protoplanetary disk. It has a separation of 28 AU from the host star and is likely shepherding the inner part of the disk.^[15]

The HD 135344 B (SAO 206462) planetary system

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (years)	Eccentricity	Inclination	Radius
b (unconfirmed)	2[15] MJ	28[15]	—	—	—	2[15] RJ
(unconfirmed)	—	66±3[13]	424±25[13]	—	—	—
CC1 (unconfirmed)	0.8±0.3[14] MJ	300.8+9.9 −9.5[14]	—	—	—	—