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 |
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]
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]
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 MJ (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]
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 | — | — |