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词条 KH 15D
释义

  1. Discovery

  2. Hypotheses

  3. See also

  4. References

{{Sky|6|41|10.3387| +|9|28|33.4310}}{{Starbox begin
| name = KH 15D{{Starbox image
| image =
| caption = KH 15D in NGC 2264
| credit = ESO{{Starbox observe
| epoch = J2000.0
| constell = Monoceros
| ra = {{RA|6|41|10.31}}[1]
| dec = {{DEC|+9|28|33.2}}[1]
| appmag_v = 15.5 - 21.5[3]{{Starbox character
|component1=A
| type = Pre-main-sequence
| variable = T Tauri star
| class = K7[1]
| appmag_1_passband = V
| appmag_1 = {{val|16.039|0.003}}[2]
| appmag_2_passband = R
| appmag_2 = {{val|15.257|0.005}}[2]
| appmag_3_passband = I
| appmag_3 = {{val|14.489|0.001}}[2]
| appmag_4_passband = J
| appmag_4 = {{val|13.504|0.017}}[2]
| appmag_5_passband = H
| appmag_5 = {{val|12.825|0.015}}[2]
| appmag_6_passband = K
| appmag_6 = {{val|12.541|0.014}}[2]
| component2=B
| type2 = Pre-main-sequence
| variable2 = T Tauri star
| class2= K1±0.5[3]
| appmag_1_passband2 = V
| appmag_1_2 = {{val|15.509|0.009}}[2]
| appmag_2_passband2 = R
| appmag_2_2 = {{val|14.776|0.008}}[2]
| appmag_3_passband2 = I
| appmag_3_2 = {{val|14.198|0.009}}[2]
| appmag_4_passband2 = J
| appmag_4_2 = {{val|13.285|0.010}}[2]
| appmag_5_passband2 = H
| appmag_5_2 = {{val|12.570|0.013}}[2]
| appmag_6_passband2 = K
| appmag_6_2 = {{val|12.421|0.022}}[2]{{Starbox astrometry
| component1=A
| parallax = 1.27
| p_error = 0.08
| parallax_footnote =[18][19]
| absmag_v = {{val|6.756|0.055}}[2]
| dist_pc = {{val|773|50.0|43.6}}[4]
| component2=B
| parallax2 = 1.27
| p_error2 = 0.08
| parallax_footnote2 =[18][19]
| absmag_v2 = {{val|6.226|0.056}}[2]
| dist_pc2 = {{val|773|50.0|43.6}}[4]{{Starbox orbit
| primary = B
| name = A
| period_unitless =48.37 days[1]
| axis_unitless = 0.25 AU[27]
| eccentricity = {{val|0.574|0.017}}[27]
| inclination = {{val|92.5|2.5}}[27]{{Starbox detail
| component1=A
| mass = {{val|0.715|0.005}}[2]
| radius = {{val|1.41|0.05}}[2]
| temperature = {{val|3970|40}}[2]
| component2=B
| mass2 = {{val|0.74|0.09|0.04}}[2]
| radius2 = {{val|1.52|0.16}}[2]
| temperature2 = {{val|4140|155}}[2]{{Starbox catalog
| names = V582 Monocerotis[5]{{Starbox reference
| Simbad = V582Mon{{Starbox end}}

KH 15D (V582 Monocerotis), described as a winking star because of its unusual dips in brightness,[37] is a binary T Tauri star system embedded in a circumbinary disk. It is a member of the young open cluster NGC 2264, located about {{convert|770|pc|ly|order=flip|lk=on}} from the Sun in the constellation of Monoceros.

Discovery

The unique brightness variations of KH 15D were discovered at Wesleyan University's Van Vleck Observatory in 1996 by Dr William Herbst and his then-masters student Kristin Kearns.[38] The star was found to alternate, on a 48.37-day period,[1] between a brighter "on" state and a fainter "off" state that was less than 4% of the bright state. As the years went by, the star spent more and more time "off", such that by 2010 it was always in the faint state, although still periodically variable. In 2012 it unexpectedly began to wink on and off again and it has now entered a phase where its "on" state is almost twice as bright as it was in the mid-1990s (see light curve).

Hypotheses

A consensus model of this puzzling behavior has emerged, which attributes the winking to the rising and setting of one star relative to the edge of a circumbinary ring that occults part of the orbit.[40][41][42][43] Precession of the ring has caused the gradual evolution of the winking behavior as shown in the diagrams below. Radial velocity measurements confirmed the system as a spectroscopic binary[44] composed of two weak-lined T Tauri stars.[45]

The orbit of the binary system is nearly edge-on to our line of sight and the circumbinary disk is tilted with respect to that orbit, resulting in nodal precession. At the time of the 1996 observation only one star (designated star A) was visible while the occulting ring fully blocked the light from star B. The winking observed was caused by star A rising and setting from behind the ring. By 2010, the ring covered both stars and the system was permanently in the "off" state, being seen only by scattered light off the ring. By 2018, star B was fully uncovered and star A fully occulted. Star B has turned out to be somewhat brighter, hotter and more massive than star A, but the labels have not been changed since this might cause confusion in the literature.[6][48][49]

The importance of KH 15D derives from the unique opportunity it provides to study the terrestrial planet formation zone of a protoplanetary disk. From its rate of precession it is known that the occulting ring is located about 3 AU from the stars,[27] which would put it at the asteroid belt in the Solar System. The age of KH 15D is around 3 Myr and its total mass is around 1.5 solar masses,[2] so the system may provide some guidance on when and how planetesimals – the precursors of planets such as the Earth – form. The regular occultations also provide opportunities to study the magnetospheres and photospheres of T Tauri stars in unprecedented detail.[27]

{{clear}}

See also

{{div col|colwidth=30em}}
  • Disrupted planet
  • EPIC 204376071, unusual dimming (up to 80%).
  • KIC 8462852 – Tabby's star
  • KOI 126
  • 1SWASP J140747.93-394542.6 − star with unusual ring system eclipses
  • PDS 110 − star surrounded with a disk of dust
  • Przybylski's Star − star with unusual short-lived elements (i.e., technetium and promethium)
  • PSR B1919+21 − pulsar mistaken as alien radio signal (LGM-1)
  • RZ Piscium − star with unusual light fluctuations
  • WD 1145+017 − star ripping apart a planetesimal, producing a dusty disk
{{div col end}}

References

1. ^1 2 {{cite journal |title=Eclipses by a Circumstellar Dust Feature in the Pre-main-Sequence Star KH 15D |journal=The Astronomical Journal |last1=Hamilton |first1=Catrina M. |last2=Herbst |first2=William |last3=Shih |first3=Candice |last4=Ferro |first4=Anthony J. |display-authors=1 |date=2001 |volume=554 |issue=2 |pages=L201–L204 |doi=10.1086/321707 |bibcode=2001ApJ...554L.201H |arxiv=astro-ph/0105412}}
2. ^1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 {{cite journal |title=Optical and Radio Observations of the T Tauri Binary KH 15D (V582 Mon): Stellar Properties, Disk Mass Limit, and Discovery of a CO Outflow |journal=The Astronomical Journal |last1=Aronow |first1=Rachel A. |last2=Herbst |first2=William |last3=Hughes |first3=A. Meredith |last4=Wilner |first4=David J. |last5=Winn |first5=Joshua N. |display-authors=1 |volume=155 |issue=1 |year=2018 |pages=47 |doi=10.3847/1538-3881/aa9ed7 |bibcode=2018AJ....155...47A |arxiv=1711.11434}}
3. ^1 {{cite journal |title=Locating the Trailing Edge of the Circumbinary Ring in the KH 15D System |journal=The Astrophysical Journal Letters |last1=Capelo |first1=Holly L. |last2=Herbst |first2=William |last3=Leggett |first3=S. K. |last4=Hamilton |first4=Catrina M. |last5=Johnson |first5=John A. |display-authors=1 |date=2012 |volume=757 |issue=1 |page=L18 |arxiv=1208.5497 |doi=10.1088/2041-8205/757/1/L18 |bibcode=2012ApJ...757L..18C}}
4. ^1 {{cite journal |title=Estimating distances from parallaxes IV: Distances to 1.33 billion stars in Gaia Data Release 2 |journal=The Astronomical Journal |volume=156 |issue=2 |pages=58 |last1=Bailer-Jones |first1=C. A. L. |last2=Rybizki |first2=J. |last3=Fouesneau |first3=M. |last4=Mantelet |first4=G. |last5=Andrae |first5=R. |display-authors=1 |arxiv=1804.10121 |date=April 2018|doi=10.3847/1538-3881/aacb21 }}
5. ^{{cite simbad |title=V582 Mon |access-date=25 June 2018}} — some of the data is located under "Measurements".
6. ^{{cite arXiv |title=On the naming convention used for multiple star systems and extrasolar planets |date=2010 |eprint=1012.0707 |class=astro-ph.SR |last1= Hessman |first1=F. V. |last2= Dhillon |first2=V. S. |last3= Winget |first3=D. E. |last4= Schreiber |first4=M. R. |last5= Horne |first5=K. |last6= Marsh |first6=T. R. |last7= Guenther |first7=E. |last8= Schwope |first8=A. |last9= Heber |first9=U. }}
7. ^1 {{cite journal |title=The History of the Mysterious Eclipses of KH 15D: Asiago Observatory, 1967-1982 |journal=The Astronomical Journal |last1=Johnson |first1=John A. |last2=Winn |first2=Joshua N. |display-authors=1 |date=2004 |volume=127 |issue=4 |pages=2344–2351 |doi=10.1086/382520 |bibcode=2004AJ....127.2344J |arxiv=astro-ph/0312428}}
8. ^1 {{cite journal |title=The History of the Mysterious Eclipses of KH 15D. II. Asiago, Kiso, Kitt Peak, Mount Wilson, Palomar, Tautenburg, and Rozhen Observatories, 1954-1997 |journal=The Astronomical Journal |last1=Johnson |first1=John A. |last2=Winn |first2=Joshua N. |last3=Rampazzi |first3=Francesca |last4=Barbieri |first4=Cesare |last5=Mito |first5=Hiroyuki |last6=Tarusawa |first6=Ken-ichi |last7=Tsvetkov |first7=Milcho |last8=Borisova |first8=Ana |last9=Meusinger |first9=Helmut |display-authors=1 |date=2005 |volume=129 |issue=4 |pages=1978–1984 |doi=10.1086/428597 |bibcode=2005AJ....129.1978J |arxiv=astro-ph/0412498}}
9. ^1 2 {{cite journal |title=The Gaia mission |journal=Astronomy & Astrophysics |last1=Prusti |first1=T. |last2=De Bruijne |first2=J. H. J. |last3=Brown |first3=A. G. A. |last4=Vallenari |first4=A. |last5=Babusiaux |first5=C. |last6=Bailer-Jones |first6=C. A. L. |last7=Bastian |first7=U. |last8=Biermann |first8=M. |last9=Evans |first9=D. W. |last10=Eyer |first10=L. |last11=Jansen |first11=F. |last12=Jordi |first12=C. |last13=Klioner |first13=S. A. |last14=Lammers |first14=U. |last15=Lindegren |first15=L. |last16=Luri |first16=X. |last17=Mignard |first17=F. |last18=Milligan |first18=D. J. |last19=Panem |first19=C. |last20=Poinsignon |first20=V. |last21=Pourbaix |first21=D. |last22=Randich |first22=S. |last23=Sarri |first23=G. |last24=Sartoretti |first24=P. |last25=Siddiqui |first25=H. I. |last26=Soubiran |first26=C. |last27=Valette |first27=V. |last28=Van Leeuwen |first28=F. |last29=Walton |first29=N. A. |last30=Aerts |first30=C. |display-authors=1 |volume=595 |pages=A1 |year=2016 |doi=10.1051/0004-6361/201629272 |arxiv=1609.04153 |bibcode=2016A&A...595A...1G}}
10. ^1 2 {{cite DR2|3326686439745822336}}
11. ^1 2 {{cite journal |bibcode=2005AJ....129..829D |doi=10.1086/426326 |title=The T Tauri Star Population of the Young Cluster NGC 2264 |journal=The Astronomical Journal |last1=Dahm |first1=S. E. |last2=Simon |first2=Theodore |display-authors=1 |volume=129 |issue=2 |pages=829 |year=2005}}
12. ^1 2 3 4 5 6 {{cite journal |title=The Orbit and Occultations of KH 15D |journal=The Astronomical Journal |last1=Winn |first1=Joshua N. |last2=Hamilton |first2=Catrina M. |last3=Herbst |first3=William |last4=Hoffman |first4=Jennifer L. |last5=Holman |first5=Matthew J. |last6=Johnson |first6=John A. |last7=Kuchner |first7=Marc J. |display-authors=1 |date=2006 |volume=644 |issue=1 |pages=510–524 |doi=10.1086/503417 |bibcode=2006ApJ...644..510W |arxiv=astro-ph/0602352}}
13. ^1 {{cite news |url=https://www.nytimes.com/2002/06/20/us/star-s-wink-may-be-clue-to-creation-of-planets.html |title=Star's 'Wink' May Be Clue To Creation of Planets |work=The New York Times |last1=Wilford |first1=John Noble |date=20 June 2002 |accessdate=26 June 2018}}
14. ^1 {{cite journal |title=Additional Periodic Variables in NGC 2264 |journal=The Astronomical Journal |last1=Kearns |first1=Kristin E. |last2=Herbst |first2=William |display-authors=1 |date=1998 |volume=116 |issue=1 |pages=261–265 |doi=10.1086/300426 |bibcode=1998AJ....116..261K}}
15. ^1 {{cite journal |title=KH 15D: Gradual Occultation of a Pre-Main-Sequence Binary |journal=The Astrophysical Journal |last1=Winn |first1=Joshua N. |last2=Holman |first2=Matthew J. |last3=Johnson |first3=John A. |last4=Stanek |first4=Krzysztof Z. |last5=Garnavich |first5=Peter M. |display-authors=1 |date=2004 |volume=603 |issue=1 |pages=L45–L48 |doi=10.1086/383089 |bibcode=2004ApJ...603L..45W |arxiv=astro-ph/0312458}}
16. ^1 {{cite journal |title=The Circumbinary Ring of KH 15D |journal=The Astrophysical Journal |last1=Chiang |first1=Eugene I. |last2=Murray-Clay |first2=Ruth A. |display-authors=1 |date=2004 |volume=607 |issue=2 |pages=913–920 |doi=10.1086/383522 |bibcode=2004ApJ...607..913C |arxiv=astro-ph/0312515}}
17. ^1 {{cite journal |title=The Light Curve of the Weakly Accreting T Tauri Binary KH 15D from 2005-2010: Insights into the Nature of its Protoplanetary Disk |journal=The Astronomical Journal |last1=Herbst |first1=William |last2=LeDuc |first2=Katherine |last3=Hamilton |first3=Catrina M. |last4=Winn |first4=Joshua N. |last5=Ibrahimov |first5=Mansur |last6=Mundt |first6=Reinhard |last7=Johns-Krull |first7=Christopher M. |display-authors=1 |date=2010 |volume=140 |issue=6 |pages=2025–2035 |doi=10.1088/0004-6256/140/6/2025 |arxiv=1007.4212 |bibcode=2010AJ....140.2025H}}
18. ^1 {{cite journal |title=Complex Variability of the Hα Emission Line Profile of the T Tauri Binary System KH 15D: The Influence of Orbital Phase, Occultation by the Circumbinary Disk, and Accretion Phenomena |journal=The Astrophysical Journal |last1=Hamilton |first1=Catrina M |last2=Johns-Krull |first2=Christopher M. |last3=Mundt |first3=Reinhard |last4=Herbst |first4=William |last5=Winn |first5=Joshua N. |display-authors=1 |date=2012 |volume=751 |issue=2 |page=147 |doi=10.1088/0004-637X/751/2/147 |arxiv=1204.1334 |bibcode=2012ApJ...751..147H}}
19. ^1 {{cite journal |title=KH 15D: A Spectroscopic Binary |journal=The Astronomical Journal |last1=Johnson |first1=John A. |last2=Marcy |first2=Geoffrey W. |last3=Herbst |first3=William |last4=Johns-Krull |first4=Christopher M. |display-authors=1 |date=2004 |volume=128 |issue=3 |pages=1265–1272 |doi=10.1086/422735 |bibcode=2004AJ....128.1265J |arxiv=astro-ph/0403099}}
20. ^1 {{cite journal |title=Natural Coronagraphic Observations of the Eclipsing T Tauri System KH 15D: Evidence of Accretion and Bipolar Outflow in a Weak-Line T Tauri Star |journal=The Astrophysical Journal |last1=Hamilton |first1=Catrina M. |last2=Herbst |first2=William |last3=Mundt |first3=Reinhard |last4=Bailer-Jones |first4=Coryn A. L. |last5=Johns-Krull |first5=Christopher M. |display-authors=1 |date=2003 |volume=591 |issue=1 |pages=L45–L48 |doi=10.1086/377039 |bibcode=2003ApJ...591L..45H |arxiv=astro-ph/0305477}}
21. ^1 {{cite journal |title=Untangling the Near-IR Spectral Features in the Protoplanetary Environment of KH 15D |journal=The Astrophysical Journal |last1=Arulanantham |first1=Nicole A. |last2=Herbst |first2=William |last3=Gilmore |first3=Martha S. |last4=Cauley |first4=P. Wilson |last5=Leggett |first5=S. K. |display-authors=1 |date=2017 |volume=834 |issue=2 |page=119 |doi=10.3847/1538-4357/834/2/119 |bibcode=2017ApJ...834..119A |arxiv=1611.09319}}
22. ^1 {{cite web |url=https://www.aavso.org/vsx/index.php?view=detail.top&oid=19410 |title=V582 Monocerotis |work=The International Variable Star Index |publisher=American Association of Variable Star Observers |accessdate=29 June 2018}}
[7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]
}}{{Stars of Monoceros}}

5 : T Tauri stars|Monoceros (constellation)|Spectroscopic binaries|Objects with variable star designations|K-type stars
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