请输入您要查询的百科知识：

　

词条 UScoCTIO 108
释义

  1. References

  2. External links

{{Starbox begin
| name=UScoCTIO 108A}}{{Starbox observe
| epoch=J2000.0 (ICRS)
| constell=Scorpius
| ra={{RA|16|05|53.94}}[1]
| dec={{DEC|−18|18|42.7}}[1]
}}{{Starbox character
| class = M7
}}{{Starbox astrometry
|prop_mo_ra=-7.4 ± 4.6[4]|prop_mo_dec=-20.4 ± 4.6[4]
| dist_pc = 145 ± 2
| dist_ly = 473 ± 6
}}{{Starbox detail
| mass = 0.057 ± 0.019
| radius2 = 0.46
| luminosity = 0.011{{±|0.06|0.03}}
| temperature = 2700 ± 100
}}{{Starbox reference
| Simbad=UScoCTIO+108
}}{{Starbox end}}{{Starbox begin
| name=UScoCTIO 108B
}}{{Starbox relpos
| primary = A
| epoch = J2007.5
| angdistsec = 4.6 ± 0.1
| angdistmas =
| angdistref =
| posang = 177 ± 1
| posangref =
| projsep = ~670
| projsepref =
}}{{Starbox character
| class = M9.5 ± 0.5[14]
}}{{Starbox detail
| mass = 0.015{{±|0.009|0.004}}[14] |radius=0.16 ± 0.01[14]
| luminosity = 0.00065 ± 0.00007[14]
| temperature = 2300 ± 100[14] |gravity=4.0 ± 0.5[14]
}}{{Starbox catalog
| names=UscoCTIO 108b[2]
}}{{Starbox reference
|Simbad=NAME+UScoCTIO+108b
}}{{Starbox end}}UScoCTIO 108 is a binary system, approximately 470 light-years away in the Upper Scorpius (USco) OB association. The primary, UScoCTIO 108A, with mass around 0.06 solar masses, is a brown dwarf or low-mass red dwarf. The secondary, UScoCTIO 108B, with a mass around the deuterium burning limit of 13 Jupiter masses, would be classified as either a brown dwarf or an extrasolar planet.

The primary component of the system was discovered in 2000 as a possible member of the Upper Scorpius association, based on its position in a HR diagram, in a search for new member of the association by the Cerro Tololo Inter-American Observatory (CTIO), where it received the designation UScoCTIO 108.[22] Later, spectroscopic and photometric observations confirmed that the object is a real member of the association, showing signs of low gravity and youth, and estimated a mass of 60 times the mass of Jupiter (MJ), an effective temperature of 2,800 K and a spectral type of M7. The low mass indicates that the object is not able to sustain hydrogen fusion, making it a brown dwarf.

The secondary member of the system was found in 2008 as an object located at a separation of 4.6 arcseconds, which corresponds to a physical separation of more than 670 AU, and is also a confirmed member of the Upper Scorpius association. Its spectrum shows it is also a cold substellar object, with an effective temperature of 2,300 K and a spectral type of M9.5.[14] Its mass was originally estimated at 14 MJ, very close to the nominal boundary between planets and brown dwarf, but a recent revision of the age of the Upper Scorpius association to 11 million years increased this value to 16 MJ, indicating that the object is likely a low mass brown dwarf.[27] The physical association between the two brown dwarfs has not been confirmed by observation of common proper motion, but is considered very likely given the proximity between them.[4]

The minimum separation between the two brown dwarfs, 670 AU, is much larger than the mean of other similar mass systems, and indicates that the pair (if they really form a binary system) is very weakly bound, with a escape velocity for the secondary component of only 0.4 km/s. Considering the average stellar density in an association like Upper Scorpius, it is estimated that perturbations by passing stars will cause the rupture of the system in a few million years.

Observations by the infrared telescope WISE revealed excess emission at 12 and 22 μm, indicating the presence of a debris disk around of the brown dwarfs.[31]

References

1. ^1 {{SIMBAD link|UScoCTIO+108|UScoCTIO 108}}, entry, SIMBAD. Accessed on line June 17, 2008.
2. ^{{SIMBAD link|NAME+UScoCTIO+108b|NAME UScoCTIO 108b}}, entry, SIMBAD. Accessed on line June 17, 2008.
3. ^1 {{cite journal|author=Ardila, David; Martín, Eduardo; Basri, Gibor|title=A Survey for Low-Mass Stars and Brown Dwarfs in the Upper Scorpius OB Association|journal=The Astronomical Journal|volume=120|issue=1|pages= 479–487|date=July 2000|bibcode=2000AJ....120..479A|doi=10.1086/301443|arxiv=astro-ph/0003316}}
4. ^1 {{cite journal|author=Pecaut, Mark J. |author2=Mamajek, Eric E. |author3=Bubar, Eric J.|title=A Revised Age for Upper Scorpius and the Star Formation History among the F-type Members of the Scorpius-Centaurus OB Association|journal=The Astrophysical Journal|volume=746|issue=2|pages=article 154, 22 pp.|date=February 2012|bibcode=2012ApJ...746..154P|doi=10.1088/0004-637X/746/2/154|arxiv=1112.1695}}
5. ^1 {{cite journal|author=Morales, Farisa Y. |author2=Padgett, D. L. |author3=Bryden, G. |author4=Werner, M. W. |author5=Furlan, E.|title=WISE Detections of Dust in the Habitable Zones of Planet-bearing Stars|journal=The Astrophysical Journal|volume=757|issue=1|pages=artigo 7, 6 pp.|date=September 2012|bibcode=2012ApJ...757....7M|doi=10.1088/0004-637X/757/1/7}}
6. ^1 2 3 4 5 6 7 {{cite journal|author=Bonnefoy, M.|display-authors=etal|title=A library of near-infrared integral field spectra of young M-L dwarfs|journal=Astronomy & Astrophysics|volume=562|issue=|pages=A127, 26 pp.|date=February 2014|bibcode=2014A&A...562A.127B|doi=10.1051/0004-6361/201118270|arxiv=1306.3709}}
7. ^1 2 3 {{cite journal|author=Ginski, C.|display-authors=etal|title=Astrometric follow-up observations of directly imaged sub-stellar companions to young stars and brown dwarfs|journal=Monthly Notices of the Royal Astronomical Society|volume=444|issue=3|pages=2280–2302|date=November 2014|bibcode=2014MNRAS.444.2280G|doi=10.1093/mnras/stu1586|arxiv=1409.1850}}
[3][4][5][6][7]
}}

External links

  • Star: UScoCTIO 108, Extrasolar Planets Encyclopaedia. Accessed on line June 17, 2008.
{{Stars of Scorpius}}

4 : Brown dwarfs|M-type main-sequence stars|Scorpius (constellation)|Upper Scorpius
随便看

　

开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。

　

Copyright © 2023 OENC.NET All Rights Reserved
京ICP备2021023879号 更新时间：2024/9/30 6:34:59