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 The white dwarf GD 165 A is seen in the center of the image as a bright star. The brown dwarf GD 165 B is below the white dwarf, seen as a red spot. | |
| Observation data Epoch J2000[1] Equinox J2000[1] | |
|---|---|
| Constellation | Boötes |
| Right ascension | 14h 24m 39.144s[1] |
| Declination | 09° 17′ 13.98″[1] |
| Characteristics | |
| Evolutionary stage | white dwarf + brown dwarf |
| Spectral type | DA4[2]+L4[3] |
| Astrometry | |
| Radial velocity (Rv) | -26.8 ± 4.3[4] km/s |
| Proper motion (μ) | RA: -213.353 ± 0.084[5] mas/yr Dec.: -149.648 ± 0.074[5] mas/yr |
| Parallax (π) | 29.9335 ± 0.0559 mas[5] |
| Distance | 109.0 ± 0.2 ly (33.41 ± 0.06 pc) |
| Details | |
| GD 165 A | |
| Mass | 0.64 ± 0.02[6] M☉ |
| Radius | 0.0124 ± 0.0003[6] R☉ |
| Luminosity | 0.0030 ± 0.0006[6] L☉ |
| Surface gravity (log g) | 8.052 ± 0.035[6] cgs |
| Temperature | 12,130 ± 450[6] K |
| Rotation | 57.29 ± 0.34 hours[6] |
| Age | 1.2-5.5[7] Gyr |
| GD 165 B | |
| Mass | 62.58 ± 15.57[8] MJup |
| Radius | 1.00 ± 0.08[8] RJup |
| Surface gravity (log g) | 5.19 ± 0.21[8] cgs |
| Temperature | 1755 ± 102[8] K |
| Age | 1.2-5.5[7] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | GD 165 A |
| GD 165 B | |
GD 165 is a binary white dwarf and brown dwarf system located in the Boötes constellation, roughly 109 light-years from Earth.[7] Neither of the stars have any known exoplanets.
Nomenclature and observation
[edit]The system GD 165 is named after Henry L. Giclas, an American Astronomer who lived throughout the 20th century.[9]
GD 165 B was discovered in 1988 by Becklin and Zuckerman at the University of California, Los Angeles.[10] GD 165 B was the first brown dwarf discovered to be cooler than M-Type stars[11] and was initially assigned the spectral type ≥M10. It would not be recognized as a brown dwarf until 1999, when new spectral types L-Type and T-Type for objects cooler than M-type stars were established, reclassifying GD 165 B as L4.[3]
Physical properties
[edit]GD 165 A is a pulsating white dwarf with a temperature of about 12,100 K, a mass of 0.64 M☉, and a radius of 0.0124 R☉.[6] GD 165 A has an extremely dim luminosity of 0.0030L☉,[6] making it completely invisible to the naked eye.
GD 165 B is an L-Type brown dwarf with a temperature of about 1,750 K, a mass of about 63 MJ, and a radius of 1.00 RJ.[8] GD 165B is separated by 123±12 astronomical units from its host white dwarf. It is the second closest spacially resolved brown dwarf after PHL 5038, which has a separation of around 69 AU.[12] It produces almost no light and is completely invisible to the naked eye.
See also
[edit]Other cooler than M brown dwarfs, discovered before 1998:
- Gliese 229 B - T6.5[13][14]
- 2MASP J0345432+254023 - L0 (first isolated L-dwarf)[3]
- DENIS-P J020529.0-115925 - L7[3][15]
- DENIS-P J1058.7-1548 - L3[3] [15]
- DENIS-P J1228.2-1547 - L5[3][15]
- Kelu-1 - L2[3][16]
References
[edit]- ^ a b c d "V* CX Boo -- Pulsating White Dwarf". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2013-09-23.
- ^ Kirkpatrick, J. Davy; Beichman, Charles A.; Skrutskie, Michael F. (1997). "The Coolest Isolated M Dwarf and Other 2MASS Discoveries". The Astrophysical Journal. 476 (1): 311–318. Bibcode:1997ApJ...476..311K. doi:10.1086/303613.
- ^ a b c d e f g Kirkpatrick, J. Davy; Reid, I. Neill; Liebert, James; Cutri, Roc M.; Nelson, Brant; Beichman, Charles A.; Dahn, Conard C.; Monet, David G.; Gizis, John E.; Skrutskie, Michael F. (1999). "Dwarfs Cooler than "M": The Definition of Spectral Type "L" Using Discoveries from the 2 Micron All-Sky Survey (2MASS)" (PDF). The Astrophysical Journal. 519 (2): 802–833. Bibcode:1999ApJ...519..802K. doi:10.1086/307414. S2CID 73569208.
- ^ Pauli, E.-M.; Napiwotzki, R.; Heber, U.; Altmann, M.; Odenkirchen, M. (February 2006). "3D kinematics of white dwarfs from the SPY project. II". Astronomy & Astrophysics. 447 (1): 173–184. arXiv:astro-ph/0510494. Bibcode:2006A&A...447..173P. doi:10.1051/0004-6361:20052730. ISSN 0004-6361.
- ^ a b c Gaia Collaboration (2018-08-01). "Gaia Data Release 2 - Summary of the contents and survey properties". Astronomy & Astrophysics. 616: A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. ISSN 0004-6361. S2CID 49211658.
- ^ a b c d e f g h i Giammichele, N.; Fontaine, G.; Brassard, P.; Charpinet, S. (March 2016). "A New Analysis of the Two Classical ZZ Ceti White Dwarfs GD 165 and Ross 548. II. Seismic Modeling". Astrophysical Journal Supplement Series. 223 (1): 10. Bibcode:2016ApJS..223...10G. doi:10.3847/0067-0049/223/1/10. ISSN 0067-0049. S2CID 124354534.
- ^ a b c Kirkpatrick, J. Davy; Allard, France; Bida, Tom; Zuckerman, Ben; Becklin, E. E.; Chabrier, Gilles; Baraffe, Isabelle (July 1999). "An Improved Optical Spectrum and New Model FITS of the Likely Brown Dwarf GD 165B". Astrophysical Journal. 519 (2): 834–843. Bibcode:1999ApJ...519..834K. doi:10.1086/307380. ISSN 0004-637X.
- ^ a b c d e Filippazzo, Joseph C.; Rice, Emily L.; Faherty, Jacqueline; Cruz, Kelle L.; Van Gordon, Mollie M.; Looper, Dagny L. (September 2015). "Fundamental Parameters and Spectral Energy Distributions of Young and Field Age Objects with Masses Spanning the Stellar to Planetary Regime". Astrophysical Journal. 810 (2): 158. arXiv:1508.01767. Bibcode:2015ApJ...810..158F. doi:10.1088/0004-637X/810/2/158. ISSN 0004-637X. S2CID 89611607.
- ^ Dictionary of Nomenclature of Celestial Objects. GD entry. SIMBAD. Centre de Données astronomiques de Strasbourg.
- ^ Becklin, E. E.; Zuckerman, B. (1988). "A low-temperature companion to a white dwarf star". Nature. 336 (Dec. 15, 1988): 656–658. Bibcode:1988Natur.336..656B. doi:10.1038/336656a0. S2CID 4358564.
- ^ Dahn, C. C.; Harris, Hugh C.; Vrba, Frederick J.; Guetter, Harry H.; Canzian, Blaise; Henden, Arne A.; Levine, Stephen E.; Luginbuhl, Christian B.; Monet, Alice K. B.; Monet, David G.; Pier, Jeffrey R.; Stone, Ronald C.; Walker, Richard L.; Burgasser, Adam J.; Gizis, John E.; Kirkpatrick, J. Davy; Liebert, James; Reid, I. Neill (2002). "Astrometry and Photometry for Cool Dwarfs and Brown Dwarfs". The Astronomical Journal. 124 (2): 1170–1189. arXiv:astro-ph/0205050. Bibcode:2002AJ....124.1170D. doi:10.1086/341646. S2CID 119485007.
- ^ French, Jenni R.; Casewell, Sarah L.; Dupuy, Trent J.; Debes, John H.; Manjavacas, Elena; Martin, Emily C.; Xu, Siyi (2023-03-01). "Discovery of a resolved white dwarf-brown dwarf binary with a small projected separation: SDSS J222551.65+001637.7AB". Monthly Notices of the Royal Astronomical Society. 519 (4): 5008–5016. arXiv:2301.02101. Bibcode:2023MNRAS.519.5008F. doi:10.1093/mnras/stac3807. ISSN 0035-8711.
- ^ Burgasser, Adam J.; Kirkpatrick, J. Davy; Brown, Michael E.; Reid, I. Neill; Burrows, Adam; Liebert, James; Matthews, Keith; Gizis, John E.; Dahn, Conard C.; Monet, David G.; Cutri, Roc M.; Skrutskie, Michael F. (2002). "The Spectra of T Dwarfs. I. Near-Infrared Data and Spectral Classification". The Astrophysical Journal. 564 (1): 421–451. arXiv:astro-ph/0108452. Bibcode:2002ApJ...564..421B. doi:10.1086/324033. S2CID 9273465.
- ^ Nakajima, T.; Oppenheimer, B. R.; Kulkarni, S. R.; Golimowski, D. A.; Matthews, K.; Durrance, S. T.; Neto, D. N.; Teixeira, R. (1995). "Discovery of a cool brown dwarf". Nature. 378 (6556): 463–465. Bibcode:1995Natur.378..463N. doi:10.1038/378463a0. S2CID 4351772.
- ^ a b c Delfosse, Xavier; Tinney, Chris G.; Forveille, Thierry; Epchtein, Nicolas; Bertin, Emmanuel; Borsenberger, Jean; Copet, Éric; de Batz, Bertrand; Fouqué, Pascal; Kimeswenger, Stefan; Le Bertre, Thibaut; Lacombe, François; Rouan, Daniel; Tiphène, Didier (1997). "Field brown dwarfs found by DENIS". Astronomy and Astrophysics. 327: L25–L28. Bibcode:1997A&A...327L..25D.
- ^ Ruiz, Maria Teresa; Leggett, S. K.; Allard, France (1997). "Kelu-1: A Free-floating Brown Dwarf in the Solar Neighborhood". The Astrophysical Journal Letters. 491 (2): L107–L110. Bibcode:1997ApJ...491L.107R. doi:10.1086/311070.
