HK Tauri

Last updated
HK Tauri
HKTauLightCurve.png
A light curve for HK Tauri, adapted from Roggero et al. (2021) [1]
Observation data
Epoch J2000       Equinox J2000
Constellation Taurus
A
Right ascension 04h 31m 50.5716s [2]
Declination +24° 24 17.775 [2]
Apparent magnitude  (V)15.10
B
Right ascension 04h 31m 50.6002s [3]
Declination +24° 24 15.503 [3]
Characteristics
HK Tauri A
Evolutionary stage pre-main-sequence star
Spectral type M1.5 [4]
Apparent magnitude  (G)14.106 [2]
Variable type T Tau
HK Tauri B
Spectral type M2 [4]
Apparent magnitude  (G)17.962 [3]
Astrometry
HK Tauri A
Proper motion (μ)RA: 5.076 [2]   mas/yr
Dec.: −22.944 [2]   mas/yr
Parallax (π)7.6247 ± 0.0317  mas [2]
Distance 428 ± 2  ly
(131.2 ± 0.5  pc)
HK Tauri B
Proper motion (μ)RA: 2.668 [3]   mas/yr
Dec.: −20.457 [3]   mas/yr
Parallax (π)7.780 ± 0.6322  mas [3]
Distance 420 ± 30  ly
(130 ± 10  pc)
Position (relative to HK Tauri A) [4]
ComponentHK Tauri B
Angular distance 2.32
Position angle 170.4°
Projected separation 309 AU
Details
A
Mass 0.44+0.14
0.11
[4]   M
Luminosity 0.56 [5]   L
Temperature 3680±150 [6]   K
B
Mass 0.37±0.2 [4]   M
Luminosity0.42 [5]   L
Temperature 3550±150 [6]   K
Other designations
2MASS J04315056+2424180, WISE J043150.56+242417.6
HK Tauri A: Gaia EDR3 147847072275324416, Gaia DR2 147847072275324416
HK Tauri B: Gaia EDR3 147847072275766656, Gaia DR2 147847072274696704
Database references
SIMBAD data

HK Tauri is a young binary star system in the constellation of Taurus about 434 light-years away, belonging to the Taurus Molecular Cloud.

Contents

System

Artist's impressions of the two disks surrounding both stars Artist's impression of the discs around the young stars HK Tauri A and B.jpg
Artist's impressions of the two disks surrounding both stars

The two stars of the HK Tauri system are separated by 2.32 , equivalent to 309  AU at the distance of HK Tauri. The primary is a pre-main sequence star with a mass of 0.44 M, while the secondary has a mass of 0.37 M. [4]

Properties

Both members of the binary are medium-mass objects still contracting towards the main sequence and accreting mass. Their ages are probably young (below 10 million years) but cannot be estimated with any accuracy because both stars are strongly obscured by the protoplanetary disks. [6]

Protoplanetary system

HK Tauri, with the edge-on disk around the B component with Hubble HK Tauri Hubble.jpg
HK Tauri, with the edge-on disk around the B component with Hubble

The companion star HK Tauri B is surrounded by a protoplanetary disk visible nearly edge-on. It contains water and carbon dioxide ices, along with gaseous carbon monoxide. [7] The disk is unusually flat, with an aspect ratio of 4.4, while most young stars host disks with aspect ratios of about 3. [8] The disk also contain relatively few large dust particles compared to fine dust, with a size distribution power-law slope of 4.2. The disk mass is relatively small, not larger than 0.0005M, and dust distribution is asymmetric. [9] The plane of the disk is not aligned with the orbit of the binary. [10]

Multiple planets embedded in the disk of HK Tauri B have been suspected since 1993, [11] although none were detected by 2020. [12]

The HK Tauri A planetary system [4]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
protoplanetary disk 028.7 AU 56.9±0.5°
The HK Tauri B planetary system [4]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
protoplanetary disk 068.0 AU 83.2±0.2°

Related Research Articles

<span class="mw-page-title-main">XZ Tauri</span> Star in the constellation Taurus

XZ Tauri is a binary system approximately 460 light-years away in the constellation Taurus. The system consists of two T Tauri stars orbiting each other about 6 billion kilometers apart. The system made news in 2000 when a superflare was observed in the system.

<span class="mw-page-title-main">AA Tauri</span> Star in the constellation Taurus

AA Tauri is a young variable star in the equatorial constellation of Taurus, located in the Taurus-Auriga star-forming region. It is too faint to view with the naked eye, having an apparent visual magnitude that varies from 12.2 down to 16.1. The star is located approximately 439 light-years away from the Sun based on parallax, and is drifting further away with a radial velocity of +17 km/s.

<span class="mw-page-title-main">HD 142527</span> Young star in the constellation of Lupus

HD 142527 is a binary star system in the constellation of Lupus. The primary star belongs to the Herbig Ae/Be star class, while the companion, discovered in 2012, is a red dwarf star or accreting protoplanet with a projected separation of less than 0.1″. The system is notable for its circumbinary protoplanetary disk and its discovery has helped refine models of planet formation. The orbit of companion is strongly inclined to the circumbinary protoplanetary disk.

<span class="mw-page-title-main">AC Herculis</span> Spectroscopic binary star in the constellation Hercules

AC Herculis, is an RV Tauri variable and spectroscopic binary star in the constellation of Hercules. It varies in brightness between apparent magnitudes 6.85 and 9.0.

<span class="mw-page-title-main">LkCa 15</span> Star system in the constellation Taurus

LkCa 15 is a T Tauri star in the Taurus Molecular Cloud. These types of stars are relatively young pre-main-sequence stars that show irregular variations in brightness. It has a mass that is about 97% of the Sun, an effective temperature of 4370 K, and is slightly cooler than the Sun. Its apparent magnitude is 11.91, meaning it is not visible to the naked eye.

<span class="mw-page-title-main">GG Tauri</span> Star in the constellation Taurus

GG Tauri, often abbreviated as GG Tau, is a quintuple star system in the constellation Taurus. At a distance of about 450 light years away, it is located within the Taurus-Auriga Star Forming Region. The system comprises three stars orbiting each other in a hierarchical triple system, known as GG Tauri A, and another binary star system more distant from the central system, known as GG Tauri B.

<span class="mw-page-title-main">GW Orionis</span> Star in the constellation Orion

GW Orionis is a T Tauri type pre-main sequence hierarchical triple star system. It is associated with the Lambda Orionis star-forming region and has an extended circumtrinary protoplanetary disk.

<span class="mw-page-title-main">DH Tauri</span> Star in the constellation Taurus

DH Tauri, also known as DH Tau, is a type M star, located 140 parsecs away. It forms a binary system with DI Tauri 15″ away, and has a substellar companion, either a brown dwarf or massive exoplanet.

<span class="mw-page-title-main">RW Aurigae</span> Young binary star system in the constellation Auriga

RW Aurigae is a young binary system in the constellation of Auriga about 530 light years away, belonging to the Taurus-Auriga association of the Taurus Molecular Cloud. RW Aurigae B was discovered in 1944.

<span class="mw-page-title-main">RY Tauri</span> Star in the constellation Taurus

RY Tauri is a young T Tauri star in the constellation of Taurus about 450 light years away, belonging to the Taurus Molecular Cloud. It is more massive than typical T Tauri stars, and may be an intermediate between this class and the Herbig Ae/Be star type.

<span class="mw-page-title-main">BP Tauri</span> Star in the constellation Taurus

BP Tauri is a young T Tauri star in the constellation of Taurus about 416 light years away, belonging to the Taurus Molecular Cloud.

<span class="mw-page-title-main">GI Tauri and GK Tauri</span> Binary star system in the constellation of Taurus

GK Tauri is a young T Tauri-type pre-main sequence star in the constellation of Taurus about 421 light years away, belonging to the Taurus Molecular Cloud.

<span class="mw-page-title-main">GV Tauri</span> Young binary star system in the constellation of Taurus

GK Tauri is a young binary system composed of T Tauri-type pre-main sequence stars in the constellation of Taurus about 466 light years away, belonging to the Taurus Molecular Cloud.

<span class="mw-page-title-main">DL Tauri</span> Protostar system with planetary system in the constellation of Taurus

DL Tauri is a young T Tauri-type pre-main sequence stars in the constellation of Taurus about 522 light years away, belonging to the Taurus Molecular Cloud. It is partially obscured by the foreground gas cloud rich in carbon monoxide, and is still accreting mass, producing 0.14 L due to release of accretion energy. The stellar spectrum shows the lines of ionized oxygen, nitrogen, sulfur and iron.

<span class="mw-page-title-main">HD 283572</span> Young star in constellation Taurus

HD 283572 is a young T Tauri-type pre-main sequence star in the constellation of Taurus about 414 light years away, belonging to the Taurus Molecular Cloud. It is a rather evolved protostar which already dispersed its birth shroud. The star emits a very high X-ray flux of 1031 ergs/s. That radiation flux associated with the magnetic activity induced a high coronal temperature of 3 kEv and regular flares. HD 283572 will eventually evolve to an A-type main-sequence star when on the main sequence. It is no longer accreting mass, and is magnetically decoupled from the remnants of the protoplanetary disk, belonging to the terminal, 3rd phase of the disk evolution. Submillimeter Array (SMA) 1.3mm observations of HD 283572 detected an extreme brightening event with a radio luminosity of 8.3x1016erg/s/Hz that spanned 9 hours on January 17th 2022. Although HD 283572 was observed by the SMA on 8 separate nights, millimeter emission was detected on one night only, strongly suggesting stellar variability as a result of an extreme stellar flare.

<span class="mw-page-title-main">EX Lupi</span>

EX Lupi is a young, single T-Tauri star in the southern constellation of Lupus. An irregular variable, it is the prototype of young, low-mass eruptive stars named EXors, with EX Lupi being this object's variable star designation. At its minimal activity level, EX Lupi resembles a classical T-Tauri star of the M0 dwarf type. The low latitude of this star, at a declination of −40°, makes it difficult for northern observers to view. Based on parallax measurements, it is located at a distance of about 505 light years from the Sun. The star lies next to a gap in the Lupus cloud complex, a star forming region.

<span class="mw-page-title-main">Y Tauri</span> Variable star in the constellation Taurus

Y Tauri is a carbon star located in the constellation Taurus. Parallax measurements by Gaia put it at a distance of approximately 2,170 light-years.

<span class="mw-page-title-main">HD 100453</span> Young binary in constellation Centaurus

HD 100453 is a binary star system which lies in the constellation Centaurus about 350 light years away from the Sun and is a member of the open cluster Scorpius–Centaurus association.

<span class="mw-page-title-main">CQ Tauri</span> Star in the constellation Taurus

CQ Tauri is a young variable star in the equatorial constellation of Taurus. It is too faint to be visible to the naked eye with an apparent visual magnitude that ranges from 8.7 to 12.25. The distance to this star is approximately 487 light years based on parallax measurements, and it is drifting further away with a radial velocity of ~23 km/s. It appears to be part of the T-association Tau 4. CQ Tauri lies close enough to the ecliptic to undergo lunar occultations.

<span class="mw-page-title-main">V773 Tauri</span> Star system in the constellation Taurus

V773 Tauri is a young, multiple star system in the central region of Taurus, an equatorial constellation. This is a T Tauri-type variable star that ranges in apparent visual magnitude from 10.59 down to 10.95, which is too faint to be viewed with the naked eye. Based on various estimates, the system is located at a distance of approximately 433 light years from the Sun. It lies near the dark cloud Lynds 1495.

References

  1. Roggero, Noemi; Bouvier, Jérôme; Rebull, Luisa M.; Cody, Ann Marie (July 2021). "The dipper population of Taurus seen with K2". Astronomy and Astrophysics. 651: A44. arXiv: 2106.02064 . Bibcode:2021A&A...651A..44R. doi: 10.1051/0004-6361/202140646 .
  2. 1 2 3 4 5 6 Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics . 649: A1. arXiv: 2012.01533 . Bibcode:2021A&A...649A...1G. doi: 10.1051/0004-6361/202039657 . S2CID   227254300. (Erratum:  doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  3. 1 2 3 4 5 6 Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics . 649: A1. arXiv: 2012.01533 . Bibcode:2021A&A...649A...1G. doi: 10.1051/0004-6361/202039657 . S2CID   227254300. (Erratum:  doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  4. 1 2 3 4 5 6 7 8 Manara, C. F.; Tazzari, M.; Long, F.; Herczeg, G. J.; Lodato, G.; Rota, A. A.; Cazzoletti, P.; Van Der Plas, G.; Pinilla, P.; Dipierro, G.; Edwards, S.; Harsono, D.; Johnstone, D.; Liu, Y.; Menard, F.; Nisini, B.; Ragusa, E.; Boehler, Y.; Cabrit, S. (2019), "Observational constraints on dust disk sizes in tidally truncated protoplanetary disks in multiple systems in the Taurus region", Astronomy & Astrophysics, 628: A95, arXiv: 1907.03846 , Bibcode:2019A&A...628A..95M, doi:10.1051/0004-6361/201935964, S2CID   195847916
  5. 1 2 Akeson, Rachel L.; Jensen, Eric L. N.; Carpenter, John; Ricci, Luca; Laos, Stefan; Nogueira, Natasha F.; Suen-Lewis, Emma M. (2019), "Resolved Young Binary Systems and Their Disks", The Astrophysical Journal, 872 (2): 158, arXiv: 1901.05029 , Bibcode:2019ApJ...872..158A, doi: 10.3847/1538-4357/aaff6a , S2CID   119332907
  6. 1 2 3 Simon, M.; Guilloteau, S.; Beck, Tracy L.; Chapillon, E.; Folco, E. Di; Dutrey, A.; Feiden, Gregory A.; Grosso, N.; Piétu, V.; Prato, L.; Schaefer, Gail H. (2019), "Masses and Implications for Ages of Low-mass Pre-main-sequence Stars in Taurus and Ophiuchus", The Astrophysical Journal, 884 (1): 42, arXiv: 1908.10952 , Bibcode:2019ApJ...884...42S, doi: 10.3847/1538-4357/ab3e3b , S2CID   201668492
  7. Aikawa, Y.; Kamuro, D.; Sakon, I.; Itoh, Y.; Noble, J. A.; Pontoppidan, K. M.; Fraser, H. J.; Terada, H.; Tamura, M.; Kandori, R.; Kawamura, A.; Ueno, M. (2011). "AKARI observations of ice absorption bands towards edge-on YSOs". The Molecular Universe. 280: 78. arXiv: 1112.3736 . Bibcode:2011IAUS..280P..78A.
  8. Wolff, S.; Duchêne, G.; Stapelfeldt, K.; Ménard, F.; Flores, C.; Padgett, D.; Pinte, C.; Villenave, M.; van der Plas, G.; Perrin, M. (2021), "The Anatomy of an Unusual Edge-on Protoplanetary Disk. I. Dust Settling in a Cold Disk", The Astronomical Journal, 161 (5): 238, arXiv: 2103.02665 , Bibcode:2021AJ....161..238W, doi: 10.3847/1538-3881/abeb1d , S2CID   232110830
  9. McCabe, C.; Duchêne, G.; Pinte, C.; Stapelfeldt, K. R.; Ghez, A. M.; Ménard, F. (2011). "Spatially Resolving the HK Tau B Edge-on Disk from 1.2 to 4.7 μm: A Unique Scattered Light Disk". The Astrophysical Journal. 727 (2): 90. Bibcode:2011ApJ...727...90M. doi: 10.1088/0004-637X/727/2/90 . S2CID   119547639.
  10. Fragner, M. M.; Nelson, R. P. (2009), "Evolution of warped and twisted accretion discs in close binary systems", Astronomy and Astrophysics, 511: A77, arXiv: 0912.3220 , doi:10.1051/0004-6361/200913088, S2CID   56472618
  11. Marsh, Kenneth A.; Mahoney, Michael J. (1993). "Do the Spectral Energy Distributions of GK Tauri and HK Tauri Indicate the Presence of Planetary Companions?". The Astrophysical Journal. 405: L71. Bibcode:1993ApJ...405L..71M. doi: 10.1086/186768 .
  12. Wallace, A. L.; Kammerer, J.; Ireland, M. J.; Federrath, C.; Kraus, A. L.; Maddison, S. T.; Rizzuto, A.; Birchall, E. K.; Martinache, F. (2020), "High-resolution survey for planetary companions to young stars in the Taurus molecular cloud", Monthly Notices of the Royal Astronomical Society, 498: 1382–1396, arXiv: 2008.06065 , doi: 10.1093/mnras/staa2434