 UNCOVER-BD-1 (labelled BD-1 at the bottom) andUNCOVER-BD-2 (labelled BD-2 at the top) with theJames Webb Space Telescope | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Sculptor |
| Right ascension | 00h 14m 09.00723075s |
| Declination | −30° 22′ 12.6039275″ |
| Characteristics | |
| Evolutionary stage | brown dwarf |
| Spectral type | T2.5 ± 1[1] or sdT1[2] |
| Astrometry | |
| Distance | aprx. 14700 ly or aprx. 15700 ly (4500 ± 1200[2] pc 4764+568 −130[1] pc) |
| Details | |
| Mass | 4.9+0.3 −0.2[1] MJup |
| Radius | 1.52±0.02[1] RJup |
| Luminosity (bolometric) | 10−4.236+0.028 −0.020[1] L☉ |
| Surface gravity (log g) | 3.75 ± 0.25[1] or 5.0[2] cgs |
| Temperature | 1300 ± 50[1] K |
| Metallicity | −1.0[2] |
| Age | 6.741+0.070 −0.055[1] Gyr |
| Other designations | |
| A2744-BD1, [BBL2024] UNCOVER-BD-1, MSA ID 32265, J00140901-3022126 | |
| Database references | |
| SIMBAD | data |
UNCOVER-BD-1 (also known asAbell2744-BD1, A2744-BD1) is a distantbrown dwarf. It is the most distantT dwarf discovered to date (about 4.5 or 4.8kpc).[1][2]
UNCOVER-BD-1 was discovered[1][2] in a deepJames Webb Space Telescope field calledUNCOVER, which targets the galaxy clusterAbell 2744 and is primarily used to studygalaxies. As the name says, the UNCOVER team usedNIRCam to take images andNIRSpec multiobject prismspectroscopy to take spectra of any object detected in the field.[3] The object was independently discovered by two teams. Both teams also discovered two other distant T-dwarfs.[1][2]
Langeroodi & Hjorth concluded from its position and distance that UNCOVER-BD-1 likely is located outside thethin disk of theMilky Way.[1] Burgasser et al. found a high probability (76%) of it being athick disk member, and a moderate probability (24%) of it being ahalo member. This team also found that it is likely asubdwarf and comparison with the extreme subdwarfWISEA 1810−1010 produced a better fit to the widened 1.1 μm absorption feature. This could also mean that UNCOVER-BD-1 is colder and closer than currently estimated. The spectrum in their work has several absorption features from molecules labelled. Those aremethane (CH4),water vapor (H2O),carbon monoxide (CO) andcollision induced absorption byhydrogen molecules (H2).[2] Langeroodi & Hjorth find a low mass of around 5MJ, but they also do not consider it as a subdwarf,[1] which might influence the estimates of physical properties.[2][4]
