2MASS J05325346+8246465
Template:Short description Template:Sky
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Camelopardalis |
| Right ascension | Template:RA[1] |
| Declination | Template:DEC[1] |
| Characteristics | |
| Spectral type | esdL8:[2] |
| Astrometry | |
| Radial velocity (Rv) | Template:Val[3] km/s |
| Proper motion (μ) | RA: Template:Val mas/yr[1] Dec.: Template:Val mas/yr[1] |
| Parallax (π) | 40.7097±0.4597 mas[1] |
| Distance | Template:Rnd ± Template:Rnd ly (Template:Rnd ± Template:Rnd pc) |
| Details | |
| Mass | 0.077–0.085[4] Template:Solar mass |
| Temperature | 1600[5] K |
| Metallicity [Fe/H] | −1.6[5] dex |
| Rotational velocity (v sin i) | 65 ±15[3] km/s |
| Age | ~10[5] Gyr |
| Metallicity [Fe/H] | {{{metal_fe2}}} dex |
| Other designations | |
| 2MASS J05325346+8246465,[6] 2MASS 0532+8246 | |
| Database references | |
| SIMBAD | data |
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2MASS J05325346+8246465 (abbreviated 2MASS J0532+8246) is possibly the first brown dwarf observed in the galactic halo of the Milky Way, and the first known substellar subdwarf star.[7][8] It was discovered from Two Micron All-Sky Survey data, and verified by observations at Palomar Observatory and W. M. Keck Observatory.[8] It has a low metallicity, which indicates it is an old star.[8]
The mass and temperature of 2MASS 0532+8246 makes it a rare object in stellar-substellar gap between conventional stars and brown dwarfs.[9] It produces roughly half of its luminosity from hydrogen fusion.[5] Such "gap" objects, covering a narrow range of masses but a wide range of temperatures, and powered by unsteady hydrogen fusion, are exotic but expected to be more common among low-metallicity objects like 2MASS J05325346+8246465.[10]
In 2008 it was discovered that this object is on a retrograde galactic orbit that is both eccentric and extends well away from the plane, making this object a member of the galactic halo.[11] In 2024 this object was identified as a possible member of the Thamnos populations, together with the T subdwarf CWISE J113010.07+313944.7.[2] Thamnos has two substructures called Thamnos 1 and Thamnos 2, both were identified in 2019 from Gaia data.[12] Thamnos is likely the remnant of a dwarf galaxy that was accreted into the Milky Way and consists of metal-poor stars that formed between 8 and 12.89 billion years ago.[13]
References
External links
Template:Stars of Camelopardalis
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