Cha 1107−7626 (Cha J11070768−7626326) is a free-floating planetary-mass object in the Chamaeleon I star-forming region, about distant from the

Solar System The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Sola ...

. It is the lowest-mass object with

hydrocarbons In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic; their odor is usually faint, and may b ...

detected in its disk (as of May 2025). The object is located north-west of IC 2631. Cha 1107−7626 was discovered in 2008 by Kevin Luhman et al. with the

Spitzer Space Telescope The Spitzer Space Telescope, formerly the Space Infrared Telescope Facility (SIRTF), was an infrared space telescope launched in 2003, that was deactivated when operations ended on 30 January 2020. Spitzer was the third space telescope dedicate ...

and the Magellan II telescope. The researchers estimated a spectral type of L0, due to it having weaker TiO and VO absorption compared compared to other low-mass members of the Chamaeleon I region, such as OTS 44 and Cha 110913−773444. Initially the mass was estimated to be 0.004-0.01 (4.2-10.5 ). A work by

Laura Flagg Laura may refer to: People and fictional characters * Laura (given name), including lists of people and fictional characters with the name * Laura, muse of Petrarch's poetry * Laura, the British code name for the World War I Belgian spy Marthe Cno ...

et al. (2025) observed the object with the JWST instruments

NIRSpec The NIRSpec (Near-Infrared Spectrograph) is one of the four scientific instruments flown on the James Webb Space Telescope (JWST). The JWST is the follow-on mission to the Hubble Space Telescope (HST) and is developed to receive more information ...

and

MIRI Miri () is a coastal city in north-eastern Sarawak, Malaysia, located near the border of Brunei, on the island of Borneo. The city covers an area of , located northeast of Kuching and southwest of Kota Kinabalu. Miri is the second largest ...

. This work refined the

mass Mass is an Intrinsic and extrinsic properties, intrinsic property of a physical body, body. It was traditionally believed to be related to the physical quantity, quantity of matter in a body, until the discovery of the atom and particle physi ...

of Cha 1107−7626 to 6-10 . It also detected hydrocarbons in the disk of this planetary-mass object.

The circumstellar disk

The Spitzer photometry showed an

infrared excess An infrared excess is a measurement of an astronomical source, typically a star, that in their spectral energy distribution has a greater measured infrared flux than expected by assuming the star is a blackbody radiator. Infrared excesses are of ...

, which indicated that the object is surrounded by a

circumplanetary disk A circumplanetary disk (or circumplanetary disc, short CPD) is a torus, pancake or ring-shaped accumulation of matter composed of gas, dust, planetesimals, asteroids or collision fragments in orbit around a planet. They are reservoirs of materi ...

. The optical

spectrum A spectrum (: spectra or spectrums) is a set of related ideas, objects, or properties whose features overlap such that they blend to form a continuum. The word ''spectrum'' was first used scientifically in optics to describe the rainbow of co ...

with Magellan/LDSS-3 showed strong

H-alpha Hydrogen-alpha, typically shortened to H-alpha or Hα, is a deep-red visible spectral line of the hydrogen atom with a wavelength of 656.28 nm in air and 656.46 nm in vacuum. It is the first spectral line in the Balmer series and is em ...

emission, indicating the planetary-mass object is actively accreting

hydrogen Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...

gas from the surrounding disk. New and archived observations with JWST, Magellan and VLT/SINFONI were used to study the disk in more detail. The VLT spectrum showed Paschen-beta line, which is also a sign for active accretion. The rate at which Cha 1107−7626 accretes material from the disk was estimated to be between 10^-10 and 10^-11 solar masses per year (or the mass of

2 Pallas Pallas (minor-planet designation: 2 Pallas) is the List of largest asteroids, third-largest asteroid in the Solar System by volume and mass. It is the second asteroid to have been discovered, after 1 Ceres, Ceres, and is likely a remnant ...

per year, or less). The MIRI low-resolution spectrum shows spectral features that match

emission Emission may refer to: Chemical products * Emission of air pollutants, notably: ** Flue gas, gas exiting to the atmosphere via a flue ** Exhaust gas, flue gas generated by fuel combustion ** Emission of greenhouse gases, which absorb and emit rad ...

methane Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The abundance of methane on Earth makes ...

and

ethylene Ethylene (IUPAC name: ethene) is a hydrocarbon which has the formula or . It is a colourless, flammable gas with a faint "sweet and musky" odour when pure. It is the simplest alkene (a hydrocarbon with carbon–carbon bond, carbon–carbon doub ...

, as well as hints of emission by

ethane Ethane ( , ) is a naturally occurring Organic compound, organic chemical compound with chemical formula . At standard temperature and pressure, ethane is a colorless, odorless gas. Like many hydrocarbons, ethane is List of purification methods ...

. Hydrocarbons are also very common in disks around young very low-mass stars, and the mid-infrared spectrum was found to be very similar to the low-mass star ISO-ChaI 147, located in the same star-forming region. These similarities hint at similar processes in disks around young objects with different masses and isolated planetary-mass objects might be able to form their own miniature

planetary systems A planetary system is a set of gravitationally bound non-stellar bodies in or out of orbit around a star or star system. Generally speaking, systems with one or more planets constitute a planetary system, although such systems may also consis ...

. For low-mass objects, such as WISEA J044634.16-262756.1, it is suggested that the carbon-rich gases could lead to carbon-rich atmospheres, similar to

Titan Titan most often refers to: * Titan (moon), the largest moon of Saturn * Titans, a race of deities in Greek mythology Titan or Titans may also refer to: Arts and entertainment Fictional entities Fictional locations * Titan in fiction, fictiona ...

. Additionally it could lead to carbon-poor solids on planets, if the planets are assembled from solids at a late stage. These solids lose their carbon to the gas-phase of the disk.

References

{{DEFAULTSORT:Cha 1107-7626 Circumstellar disks L-type brown dwarfs Chamaeleon Rogue planets Astronomical objects discovered in 2008

The circumstellar disk

See also

References