WD J1953−1019

WD J1953−1019 is a hierarchical triple system of white dwarfs located at about 130 parsecs (about 420 light years) from the Earth. This is the first triple system of white dwarfs to be resolved.[3][1] The three white dwarfs have an atmosphere of pure hydrogen and a mass of about 0.6 times that of the Sun.

WD J1953−1019

Pan-STARRS color composite image of the WD J1953−1019 system, with the three components annotated.[lower-alpha 1]
Observation data Epoch 2015.5      Equinox 2015.5
Constellation	Aquila
Right ascension	A:  19^h 53^m 33.11^s B:  19^h 53^m 35.99^s C:  19^h 53^m 36.02^s
Declination	A: −10° 19′ 55.10″ B: −10° 19′ 31.76″ C: −10° 19′ 29.49″
Characteristics
Evolutionary stage	White dwarf
Spectral type	DA
Apparent magnitude (V)	17.27 (A) · 16.05 (B) · 16.29 (C)
Apparent magnitude (G)	17.28 (A) · 16.35 (B) · 16.44 (C)
Apparent magnitude (B)	17.27 (A) · 16.05 (B) · 16.29 (C)
Apparent magnitude (R)	17.30 (A) · 16.30 (B) · 16.44 (C)
Apparent magnitude (g)	17.18 (A) · 16.15 (B) · 16.24 (C)
Astrometry
A
Proper motion (μ)	RA: −10.81 ± 0.25 mas/yr Dec.: −16.10 ± 0.15 mas/yr
Distance	128.36 ± 2.40 pc
B
Proper motion (μ)	RA: −11.54 ± 0.18 mas/yr Dec.: −16.33 ± 0.11 mas/yr
Distance	130.37 ± 2.11 pc
C
Proper motion (μ)	RA: −10.94 ± 0.19 mas/yr Dec.: −15.66 ± 0.12 mas/yr
Distance	130.89 ± 2.01 pc
Details[1]
Mass	A: 0.63±0.03 B: 0.62±0.03 C: 0.60±0.03 M☉
Temperature	A: 13715±310 B: 22223±360 C: 22104±350 K
Other designations
A: Gaia DR2 4190500054845023488 B: Gaia DR2 4190499986125543168 C: Gaia DR2 4190499986125543296
Database references
A
SIMBAD	data
B
SIMBAD	data
C
SIMBAD	data

The system consists of a central pair, WD J1953−1019 BC, and a distant companion, WD J1953−1019 A. WD J1953−1019 B and C correspond to the sources Gaia DR2 4190499986125543168[4] and 4190499986125543296[5] respectively. The white dwarfs of the central pair, WD J1953−1019 B and C, are separated 303.25±0.01 AU from each other while the distant companion, WD J1953−1019 A, orbits the barycenter, or center of mass, of the central binary at a distance of 6398.97±0.09 AU.[1]

The cooling age found by M. Perpinyà-Vallès and collaborators for the three white dwarfs is consistent, with an estimated value between 40 and 290 million years.[1] The three stars would each come from a star that had a mass between 1.6 and 2.6 times that of the Sun. A collision of the central pair due to Lidov-Kozai oscillations is unlikely as the system is dynamically stable.[1] However, if this collision occurred, it could produce a type Ia supernova below the Chandrasekhar mass.[1]

See also

• SDSS J0106−1000 – a short-period binary white dwarf system, in the constellation Cetus
• WD J0651+2844 – another short-period binary white dwarf system, in the constellation Gemini

Notes

1. The color composite consists of Pan-STARRS images taken in g, i, and y passband filters.[1] These filters correspond to specific wavelengths of 481 nm, 752 nm, and 962 nm, respectively.[2]

References

1. Perpinyà-Vallès, M.; Rebassa-Mansergas, A.; Gänsicke, B. T.; Toonen, S.; Hermes, J. J.; Gentile Fusillo, N. P.; Tremblay, P.-E. (February 2019). "Discovery of the first resolved triple white dwarf". Monthly Notices of the Royal Astronomical Society. 483 (1): 901–907. arXiv:1811.07752. Bibcode:2019MNRAS.483..901P. doi:10.1093/mnras/sty3149.
2. Tonry, J. L.; Stubbs, C. W.; Lykke, K. R.; Doherty, P.; Shiivers, I. S.; Gentile Fusillo, N. P.; et al. (May 2012). "The Pan-STARRS1 Photometric System". The Astrophysical Journal. 750 (2): 14. arXiv:1203.0297. Bibcode:2012ApJ...750...99T. doi:10.1088/0004-637X/750/2/99. 99.
3. "A student at the UPC's Barcelona School of Telecommunications has discovered the first resolved triple white dwarf system ever reported". BarcelonaTech. Universitat Politècnica de Catalunya. 13 February 2019. Retrieved 7 May 2019.
4. "Gaia DR2 4190499986125543168 -- White Dwarf". SIMBAD Astronomical Database. Centre de Données astronomiques de Strasbourg. Retrieved 7 May 2019.
5. "Gaia DR2 4190499986125543296 -- White Dwarf". SIMBAD Astronomical Database. Centre de Données astronomiques de Strasbourg. Retrieved 7 May 2019.