CE Antliae
Young M-dwarf with a debris disk and a directly imaged planet candidate.
CE Antliae, also designated TWA 7, is a young, low-mass star located in the constellation Antlia. It hosts a debris disk and a candidate directly imaged planet.
Discovered in 1999, the star has a spectral type of M1 and belongs to the TW Hydrae association. A detection of molecular hydrogen near the star is interpreted as weak evidence of ongoing gas accretion. A giant X-ray flare was recorded on September 7, 2010, by the MAXI/GSC instrument aboard the International Space Station.
The star’s debris disk was first imaged in scattered light in 1998 using the Hubble Space Telescope’s NICMOS instrument, though reprocessing in 2016 was required to reveal it. The image showed a dust ring viewed nearly pole-on, with a radius of about 35 astronomical units. Observations with the VLT/SPHERE instrument in 2018 tentatively detected an outer ring and a spiral arm extending from the main ring; modeling also suggested an inner ring. Additional Hubble STIS observations revealed three rings, two spiral features, and a clump. In 2000, dust around TWA 7 was inferred from an excess of submillimeter radiation, but ALMA later showed that most of that emission actually comes from a background galaxy. The disk itself was also detected by ALMA. ALMA observations further detected carbon monoxide (CO) gas, likely produced by exocomets—the first such detection of CO gas in a debris disk around an M-dwarf, a phenomenon more common around more massive stars.
In 2025, JWST’s MIRI instrument detected a point source that could be a young sub-Jovian planet with a mass of 0.3 Jupiter masses (about 100 Earth masses) and a temperature near 320 K (47 °C). This candidate could explain the main ring of the debris disk. It does not match the spectrum of a background star, though it could be consistent with an intermediate-redshift star-forming galaxy; however, the probability of such a galaxy appearing so close to TWA 7 is estimated at 0.34%. If confirmed, it would be the least massive directly imaged exoplanet. The candidate lies in a previously noted underdensity in the second ring; a second underdensity on the opposite side may be caused by orbital resonance. Before detection, the candidate’s mass was predicted to be about 2 Neptune masses (roughly 34 Earth masses).
- Discovery year
- 1999
- Spectral type
- M1
- Association
- TW Hydrae association
- X-ray flare date
- 2010-09-07
- Disk radius
- about 35 astronomical units
- Planet candidate mass
- 0.3 MJ (about 100 M🜨)
- Planet candidate temperature
- around 320 K (47 °C)
Lore & Background
CE Antliae was discovered in 1999 with a spectral type of M1 and identified as a member of the TW Hydrae association. The detection of molecular hydrogen is interpreted as a weak sign of accretion of gas near the star. A giant x-ray flare was detected on 2010-09-07 with MAXI/GSC on the ISS. The debris disk was first imaged in scattered light in 1998 with Hubble NICMOS, but needed re-processing in 2016 to reveal the disk. The observation showed a pole-on dust ring with a radius of about 35 astronomical units. An outer ring and a spiral arm originating from the main ring were tentatively detected with VLT/SPHERE in 2018, and modelling also showed evidence of an inner ring. Additional observation with Hubble STIS showed three rings, two spirals and a clump. In 2000 dust was detected around TWA 7 due to excess of submillimeter radiation, though ALMA observations showed that most emission comes from a background galaxy. The disk has detected carbon monoxide (CO) gas according to ALMA observations, likely generated by exocomets, and was the first detection of CO gas in a debris disk around an M-dwarf.
Reader's Guide
CE Antliae is significant as a young M-dwarf with a complex debris disk and a directly imaged planet candidate. The planet candidate, detected in 2025 with JWST MIRI, has a mass of 0.3 MJ (about 100 M🜨) and a temperature of around 320 K. It can explain the main ring of the debris disk and does not fit the spectrum of a background star; the probability of an intermediate-redshift star-forming galaxy appearing that close is estimated at 0.34%. If confirmed, it would be the least massive directly imaged exoplanet. The candidate was independently detected by JWST NIRCam observations, which strongly support a planetary nature. Another 2025 radial velocity study suggested a planet with a minimum mass of 12.5+3.0−3.3 M🜨 and a likely period of 15.21 days, but the detection is considered unclear as the period may correlate with the rotation period and window function. A second point-like source was also detected but needs follow-up. The disk's CO gas detection was the first for an M-dwarf debris disk, a type of detection more common around more massive stars.
Did You Know?
- CE Antliae is also known as TWA 7 and was discovered in 1999.
- The planet candidate has a mass of 0.3 MJ and a temperature of around 320 K.
Frequently Asked Questions
What is CE Antliae?
CE Antliae, also catalogued as TWA 7, is a young M1-type star in the Antlia constellation that was identified in 1999. It belongs to the TW Hydrae association and is notable for hosting both a debris disk and a directly imaged planetary candidate.
What is the planet candidate orbiting CE Antliae?
A directly imaged object with a mass of roughly 0.3 Jupiter masses (about 100 Earth masses) has been detected around this star. It stands out as one of the few young planetary companions captured in direct imaging rather than inferred from radial-velocity wobbles.
What is the famous X-ray flare event linked to CE Antliae?
On September 7, 2010, the MAXI/GSC instrument aboard the International Space Station recorded a giant X-ray flare from this star. Such energetic outbursts are characteristic of young, magnetically active M-dwarfs and shed light on their high-energy radiation environments.
How was CE Antliae's debris disk first detected?
In 1998, the Hubble Space Telescope's NICMOS instrument resolved the disk in scattered light, revealing a structure extending to roughly 35 astronomical units from the star. This made it one of the earlier examples of a debris disk imaged around a young, low-mass star.
Is CE Antliae still actively accreting gas?
A detection of molecular hydrogen near the star is interpreted as weak evidence that some gas accretion may still be taking place. This suggests the system is in a transitional phase between the protoplanetary-disk stage and a fully settled debris-disk configuration.
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