2M1207, 2M1207A or 2MASS J12073346−3932539 is a brown dwarf located in the constellation Centaurus; a companion object, 2M1207b, may be the first extrasolar planetary-mass companion to be directly imaged, and is the first discovered orbiting a brown dwarf.
2M1207 was discovered during the course of the 2MASS infrared sky survey: hence the "2M" in its name, followed by its celestial coordinates. With a fairly early (for a brown dwarf) spectral type of M8, Still glowing red hot, it will shrink to a size slightly smaller than Jupiter as it cools over the next few billion years.
An initial photometric estimate for the distance to 2M1207 was 70 parsecs. The new distance gives a fainter luminosity for 2M1207. Recent trigonometric parallax results have confirmed this moving cluster distance, leading to a distance estimate of 53 ± 1 parsec or 172 ± 3 light years.
Planetary system
Like classical T Tauri stars, many brown dwarfs are surrounded by disks of gas and dust which accrete onto the brown dwarf. 2M1207 was first suspected to have such a disk because of its broad H<sub>α</sub> line. This was later confirmed by ultraviolet spectroscopy. and with ALMA. In general, accretion from disks are known to produce fast-moving jets, perpendicular to the disk, of ejected material. This has also been observed for 2M1207; an April 2007 paper in the Astrophysical Journal reports that this brown dwarf is spouting jets of material from its poles. The jets, which extend around 10<sup>9</sup> kilometers into space, were discovered using the Very Large Telescope (VLT) at the European Southern Observatory. Material in the jets streams into space at a few kilometers per second. While previous observations with the Spitzer spectrograph already detected acetylene (C<sub>2</sub>H<sub>2</sub>) emission in the disk of 2M1207, new observations with MIRI revealed emission of a wide variety of chemicals in the disk, showing a carbon-rich chemistry. In this study 2M1207 and ISO-ChaI 147 showed the largest number of organic molecules, including the only detection of ethylene (C<sub>2</sub>H<sub>4</sub>) in this sample. The detected chemicals include 9 hydrocarbons, with diacetylene (C<sub>4</sub>H<sub>2</sub>) and benzene (C<sub>6</sub>H<sub>6</sub>) being two prominent emission lines in the spectrum of 2M1207. Other emissions by chemicals in the disk are hydrogen gas (H<sub>2</sub>), hydrogen cyanide (HCN) and carbon dioxide (CO<sub>2</sub>).
2M1207b shows weak accretion from a disk, inferred from emission lines of hydrogen and helium in medium-resolution NIRSpec data. Surprisingly 2M1207b does not show absorption due to methane, which was predicted to be present for this object. It was suggested that very young objects have a L/T-transition starts at a later spectral type.