CE Antliae

CE Antliae (also called TWA 7) is a young low-mass star in the constellation of Antlia. It is surrounded by a debris disk and has one directly imaged planet candidate.^[10]

A light curve for CE Antliae, plotted from TESS data.^[11] The star's rotation period is marked in red.

CE Antliae

VLT and MIRI observations of the disk and planet candidate around CE Antliae[1]
Observation data Epoch J2000      Equinox J2000
Constellation	Antlia
Right ascension	10h 42m 30.10s[2]
Declination	−33° 40′ 16.2″[2]
Apparent magnitude (V)	10.91±0.07[3]
Characteristics
Evolutionary stage	T Tauri star[4]
Spectral type	M1[4]
Variable type	rotational variable,[5] flare star[6]
Astrometry
Radial velocity (Rv)	10.81±4.41[2] km/s
Proper motion (μ)	RA: −118.751(23) mas/yr[2] Dec.: −19.648(26) mas/yr[2]
Parallax (π)	29.3277±0.0273 mas[2]
Distance	111.2 ± 0.1 ly (34.10 ± 0.03 pc)
Absolute magnitude (MV)	+9.0[7]
Details
Mass	0.46±0.09[8] M☉
Radius	0.92±0.12[8] R☉
Luminosity	0.115±0.019[8] L☉
Surface gravity (log g)	4.18±0.17[8] cgs
Temperature	3509±116[8] K
Rotation	4.92[5] days
Rotational velocity (v sin i)	63.2[5] km/s
Age	6.4±1.1[9] Myr
Other designations
TWA 7, CE Ant, TYC 7190-2111-1, ASAS J104230-3340.3, GSC 07190-02111, 2MASS J10423011-3340162, RX J104230.3-334014, TIC 54147487, WISE J104230.01-334016.4, Gaia DR2 5444751795151480320
Database references
SIMBAD	data

TWA 7 was discovered in 1999 with a spectral type of M1 and as a member of the TW Hydrae association.^[4] The detection of molecular hydrogen is interpreted as a weak sign of accretion of gas near the star.^[12] A giant x-ray flare was detected on 2010-09-07 with MAXI/GSC on the ISS.^[6]

Planetary system

TWA 7 disk with Gemini South telescope

The disk was first imaged in scattered light in 1998 with Hubble NICMOS, but it needed a re-processing in 2016 to reveal the disk. The observation showed a pole-on dust ring with a radius of about 35 astronomical units.^[13] An outer ring and a spiral arm originating from the main ring was tentatively detected with VLT/SPHERE in 2018. The modelling also showed evidence of an inner ring.^[14] An additional observation with Hubble STIS showed three rings, two spirals and a clump.^[15] In 2000 dust was detected around TWA 7 due to excess of submillimeter radiation.^[16] ALMA observations did however show that most emission come from a background galaxy. The disk was also detected with ALMA.^[17] The disk has detected carbon monoxide (CO) gas according to ALMA observations, which is likely generated by exocomets. It was the first detection of CO gas in a debris disk around an M-dwarf. This kind of detection is more common around more massive stars.^[18]

In 2025 JWST MIRI observations showed a point source that could be a young sub-Jovian planet with a mass of 0.3 M_J (about 100 M_🜨) and a temperature of around 320 K (47 °C). The candidate can explain the main ring of the debris disk. It also does not fit the spectrum of a background star. It could be consistent with an intermediate-redshift star-forming galaxy, but the probability of such a galaxy appearing that close to TWA 7 is estimated to be 0.34%.^[10] If confirmed as a planet, it would be the least massive directly imaged exoplanet.^[10] The candidate is located in an underdensity in ring 2 that was noticed before. Opposite to the planet candidate is another underdensity region, which could be created by orbital resonance. The mass of the candidate was previously predicted to be 2 Neptune masses (about 34 M_🜨) before it was detected.^[15][10]

This candidate planet was independently detected by observations taken with the NIRCam instrument aboard JWST. The observations strongly support a planetary nature for this object, finding a background galaxy to be unlikely. The planet's mass could be similar to Neptune's. A second point-like source was also detected, but it needs follow-up observations to determine its nature.^[19]

The CE Antliae planetary system^[15][10]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (years)	Eccentricity	Inclination	Radius
Ring 1	24.49±0.04 AU				—	—
b (candidate)	0.3 MJ	52	550	—	—	—
Ring 2	52.38±0.12 AU				—	—
Ring 3	101+2 −3 AU				—	—

See also

• List of directly imaged exoplanets
• List of resolved circumstellar disks

Other M dwarfs with debris disks

• AU Microscopii
• Fomalhaut C
• GSC 07396-00759