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词条 HD 98800
释义

  1. Stellar system

  2. Planetary system

      Debris disk    Possible planets  

  3. See also

  4. References

  5. External links

{{Starbox begin|name=HD 98800}}{{Starbox observe 2s
|epoch=J2000
|constell=Crater
|component1=HD 98800 A
|ra1={{RA|11|22|05.287}}[1]
|dec1={{DEC|-24|46|39.78}}[1]
|appmag_v1=9.59[1]
|component2=HD 98800 B
|ra2={{RA|11|22|05.288}}[1]
|dec2={{DEC|-24|46|39.05}}[1]
|appmag_v2=10.06[1]
(10.4 / 11.5)[2]
}}{{Starbox character
|component1=HD 98800 A
|class=K5V / ?[3]
|b-v=1.17 / ?[3]
|variable=
|component2=HD 98800 B
|class2=K7V / M1V[3]
|b-v2=1.37 / 1.41[3]
|variable2=
}}{{Starbox astrometry
|radial_v=
|prop_mo_ra=-85.40[4]
|prop_mo_dec=-33.10[4]
|parallax=22.27
|p_error=2.31
|parallax_footnote=[4]
|absmag_v=6.06 (Aa)[3]
6.91 ± 0.26[16]
8.02 ± 0.27[16]
}}{{Starbox orbit
|reference=[18]
|primary=HD 98800 A
|name=HD 98800 B
|period=345
|periastron=2025
|eccentricity=0.5
|axis=1.471
|node=184.8
|periarg=224.6
|inclination=88.3
}}{{Starbox orbit
|reference=[5]
|primary=HD 98800 Ba
|period_unitless=314.327 ± 0.028 d
|periastron=MJD 52481.34 ± 0.22
|eccentricity=0.7849 ± 0.0053
|k1=22.94 ± 0.34
|k2=27.53 ± 0.61
|periarg=109.6 ± 1.1
|node=337.6 ± 2.4
|inclination=66.8 ± 3.2
|axis_unitless=23.3 ± 2.5 mas
}}{{Starbox detail
|age_myr=7 ± 5[3]
|component2=HD 98800 Aa
|mass2=1.1 ± 0.1[6]
|gravity2=4.25[7]
|rotational_velocity2=5.0[7]
|temperature2=4500[7]
|radius2=1.75[7]
}}{{Starbox detail|no_heading=y
|component1=HD 98800 Ba
|mass=0.699 ± 0.064[5]
|gravity=4.21 ± 0.12[5]
|rotational_velocity=3.0[7]
|temperature=4200 ± 150[5]
|radius=1.09 ± 0.14[5]
|luminosity=0.330 ± 0.075[5]
|component2=HD 98800 Bb
|mass2=0.582 ± 0.051[5]
|gravity2=4.34 ± 0.12[5]
|rotational_velocity2=0.0[7]
|temperature2=4000 ± 150[5]
|radius2=0.85 ± 0.11[5]
|luminosity2=0.167 ± 0.038[5]
}}{{Starbox catalog
|names={{odlist|names1=TWA 4|ADS=8141 AB|CCDM=J11221-2447AB|CD=-24° 9706|GJ=2084|HD=98800|HIP=55505|V=TV Crt|SAO=179815}}
}}{{Starbox reference
|Simbad=HD+98800|sn=HD 98800
|Simbad2=HD+98800A|sn2=HD 98800A
|Simbad3=HD+98800B|sn3=HD 98800B
|ARICNS=02385|an=HD 98800A
|ARICNS2=02385|an2=HD 98800B
}}{{Starbox end}}HD 98800, also catalogued as TV Crateris (TV Crt), is a quadruple star system in the constellation of Crater (the cup). Parallax measurements made by the Hipparcos spacecraft put it at a distance of about 150 light-years (45 parsecs) away,[4] but this value is in high error. The system is located within the TW Hydrae association (TWA), and has received the designation TWA 4.[8]

The system consists of HD 98800 A and HD 98800 B each of which contains two stars. In 2007, a debris disk was discovered orbiting HD 98800 B consisting of two rings which indicates there may be an extrasolar planet orbiting within a distance of 1.5 to 2 astronomical units.

Stellar system

The system is a member of the TW Hydrae association, a group of young stars. Its membership was derived from the fact that its proper motion is similar to other stars in the group.[8]The system itself is estimated to be around 7-10 million years old.[9]

HD 98800 is a quadruple system, with two pairs of stars orbiting each other. The two pairs are separated by over an arcsecond,[10] so the wide visual orbit is poorly known. A preliminary range of orbits has been calculated, with an orbital period of 300 to 430 years, as well as a moderate eccentricity of 0.3 to 0.6.[10]

The primary component, HD 98800 A, is a K-type main-sequence star[3] with a varying radial velocity. This indicates the presence of another star orbiting it, but light from that star cannot be detected, so the system is a single-lined spectroscopic binary. The secondary system, HD 98800 B, is another spectroscopic binary, but double-lined since both stars (another K-type star and a red dwarf) can be directly detected. The stars in the HD 98800 are much larger than would be expected from their masses: at such a young age, these stars have not condensed into their normal size yet.[11]

Planetary system

{{refimprove section|date=May 2017}}

Debris disk

An infrared excess indicative of a debris disk was first discovered by IRAS.[12] Further observations of the system have been made using Keck[13] and the Spitzer Space Telescope.[14] The disk consists of two separate belts. The inner ring extends from a distance of 1.5 to 2 astronomical units from the barycenter of the central binary. The outer ring begins at approximately 5.9 astronomical units from the central binary, and extends out an undetermined distance. The gap between the two rings is ~3 astronomical units. The inner ring is thin, while the inner portion of the outer ring is dense.

Dr. Elise Furlan, leader of the Spitzer team that imaged this disk, concludes that the dust generated from the collision of rocky objects in the outer belt should eventually migrate toward the inner disk. But because the system is a double binary system, the dust particles do not evenly fill out the inner disk as expected.

Possible planets

Debris disks are thought to constitute a phase in planetary formation. Because of the gap within the debris disk, the possibility of a planet within the system becomes even more likely. The detected gap could be caused by a unique gravitational relationship between the disk and a possible planet already begun to form, carving out a clear space in the disk. However, the gap could also be gravitational resonance effects of the four stars.

See also

  • 2M1207
  • HD 188753
  • UX Tauri
  • V4046 Sagittarii

References

1. ^1 2 3 4 5 {{cite journal|title=The Tycho double star catalogue|author1=Fabricius, C.|author2=Høg, E.|author3=Makarov, V. V.|author4=Mason, B. D.|author5=Wycoff, G. L.|author6=Urban, S. E.|journal=Astronomy and Astrophysics|volume=384|pages=180–189|date=2002|bibcode=2002A&A...384..180F|doi=10.1051/0004-6361:20011822}}
2. ^{{cite web|url=http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/orb6|title=Sixth Catalog of Orbits of Visual Binary Stars|work=United States Naval Observatory}}
3. ^1 2 3 4 5 6 {{citation|last1=Song|first1=Inseok|last2=Caillault|first2=J.-P.|last3=Barrado y Navascués|first3=David|last4=Stauffer|first4=John R.|last5=Randich|first5=Sofia|title=Ages of Late Spectral Type Vega-like Stars|journal=The Astrophysical Journal|volume=533|issue=1|pages=L41–L44|date=April 2000|doi=10.1086/312597|pmid=10727387|bibcode=2000ApJ...533L..41S|arxiv=astro-ph/0002323}}
4. ^1 2 3 {{cite journal|title=Validation of the new Hipparcos reduction|url=http://www.aanda.org/index.php?option=com_article&access=bibcode&Itemid=129&bibcode=2007A%2526A...474..653VFUL|author=van Leeuwen, F.|display-authors=etal|journal=Astronomy and Astrophysics|volume=474|issue=2|pages=653–664|date=2007|arxiv=0708.1752|bibcode=2007A&A...474..653V|doi=10.1051/0004-6361:20078357}}
5. ^1 2 3 4 5 6 7 8 9 10 11 12 {{cite journal|bibcode=2005ApJ...635..442B|doi=10.1086/497328|arxiv=astro-ph/0508331|title=Dynamical Masses for Low‐Mass Pre–Main‐Sequence Stars: A Preliminary Physical Orbit for HD 98800 B|journal=The Astrophysical Journal|volume=635|issue=1|pages=442–451|year=2005|last1=Boden|first1=Andrew F.|last2=Sargent|first2=Anneila I.|last3=Akeson|first3=Rachel L.|last4=Carpenter|first4=John M.|last5=Torres|first5=Guillermo|last6=Latham|first6=David W.|last7=Soderblom|first7=David R.|last8=Nelan|first8=Ed|last9=Franz|first9=Otto G.|last10=Wasserman|first10=Lawrence H.}}
6. ^{{cite journal|bibcode=2008MNRAS.390.1377V|doi=10.1111/j.1365-2966.2008.13854.x|arxiv=0807.5105|title=HD 98800: A most unusual debris disc|journal=Monthly Notices of the Royal Astronomical Society|volume=390|issue=4|pages=1377|year=2008|last1=Verrier|first1=P. E.|last2=Evans|first2=N. W.}}
7. ^1 2 3 4 5 {{cite journal|bibcode=2009ApJ...698..660L|doi=10.1088/0004-637X/698/1/660|arxiv=0905.1907|title=The Metallicity of the Hd 98800 System|journal=The Astrophysical Journal|volume=698|issue=1|pages=660–665|year=2009|last1=Laskar|first1=Tanmoy|last2=Soderblom|first2=David R.|last3=Valenti|first3=Jeff A.|last4=Stauffer|first4=John R.}}
8. ^1 {{cite journal|bibcode=2017ApJS..228...18G|doi=10.3847/1538-4365/228/2/18|arxiv=1612.02881|title=BANYAN. IX. The Initial Mass Function and Planetary-mass Object Space Density of the TW HYA Association|journal=The Astrophysical Journal Supplement Series|volume=228|issue=2|pages=18|year=2017|last1=Gagné|first1=Jonathan|last2=Faherty|first2=Jacqueline K.|last3=Mamajek|first3=Eric E.|last4=Malo|first4=Lison|last5=Doyon|first5=René|last6=Filippazzo|first6=Joseph C.|last7=Weinberger|first7=Alycia J.|last8=Donaldson|first8=Jessica K.|last9=Lépine|first9=Sébastien|last10=Lafrenière|first10=David|last11=Artigau|first11=Étienne|last12=Burgasser|first12=Adam J.|last13=Looper|first13=Dagny|last14=Boucher|first14=Anne|last15=Beletsky|first15=Yuri|last16=Camnasio|first16=Sara|last17=Brunette|first17=Charles|last18=Arboit|first18=Geneviève}}
9. ^{{cite journal |last1=Ribas |first1=Álvaro |last2=Macías|first2= Enrique| last3=Espaillat|first3= Catherine C.| last4=Duchêne|first4= Gaspard | title=Long-lived Protoplanetary Disks in Multiple Systems: The VLA View of HD 98800 |journal=The Astrophysical Journal |date=2018 |volume=865 |issue=1 |pages=77 |doi=10.3847/1538-4357/aad81b}}
10. ^1 2 {{cite journal|bibcode=1999AstL...25..669T|title=The visual orbit of HD 98800|author=Tokovinin, A. A.|journal=Astronomy Letters|volume=25|issue=10|pages=669–671|date=1999}}
11. ^{{cite web|url=http://www.daviddarling.info/encyclopedia/T/TTauri.html|title=Encyclopedia of Science: T Tauri star|accessdate=17 January 2017}}
12. ^{{cite journal | author=Walker and Wolstencroft | title=Cool circumstellar matter around nearby main-sequence stars | journal=Publications of the Astronomical Society of the Pacific | volume=100 | pages=1509–1521 | date=1988 | doi=10.1086/132357 | bibcode=1988PASP..100.1509W}}
13. ^{{cite journal | url=http://iopscience.iop.org/1538-4357/533/1/L37/ | author=Koerner | title=A Single Circumbinary Disk in the HD 98800 Quadruple System | journal=The Astrophysical Journal | volume=533 | issue=1 | pages=L37–L40 | date=2000 | doi=10.1086/312593 | last2=Jensen | first2=E. L. N. | last3=Cruz | first3=K. L. | last4=Guild | first4=T. B. | last5=Gultekin | first5=K. | bibcode=2000ApJ...533L..37K|arxiv = astro-ph/0002227 }}
14. ^{{cite journal|title=HD 98800: A 10 Myr Old Transition Disk| url=http://iopscience.iop.org/0004-637X/664/2/1176/fulltext/|last1=Furlan|first1=E.|last2=Sargent|first2=B.|last3=Calvet|first3=N.|last4=Forrest|first4=W. J.|last5=D’alessio|first5=P.|last6=Hartmann|first6=L.|last7=Watson|first7=D. M.|last8=Green|first8=J. D.|last9=Najita|first9=J.|last10=Chen|first10=C. H.|displayauthors=1|journal=The Astrophysical Journal|volume=664|issue=2|pages=1176–1184|date=2007|arxiv=0705.0380|bibcode=2007ApJ...664.1176F|doi=10.1086/519301 }}

External links

  • {{cite web |url=http://jumk.de/astronomie/exoplanets/hd-98800.shtml |title=HD 98800 |accessdate=2008-06-20 |work=Jumk.de}}
  • {{cite web |url=http://www.spitzer.caltech.edu/images/2122-sig07-013-Evidence-for-a-Strange-Stellar-Family |title=Planets with Four Parents? Spitzer Finds Evidence for Strange Stellar Family |accessdate=2010-06-18 |work=NASA |publisher=Spitzer Space Telescope |date=2007-07-24 |first=Linda |last=Vu}}
{{Stars of Crater}}

11 : Circumstellar disks|Crater (constellation)|Henry Draper Catalogue objects|Multiple star systems|T Tauri stars|TW Hydrae association|Hypothetical planetary systems|Objects with variable star designations|Gliese and GJ objects|Hipparcos objects|Durchmusterung objects
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