Przybylski's Star

Przybylski's Star (pronounced /pʃɪˈbɪlskiz/ or /ʃɪˈbɪlskiz/), or HD 101065, is a rapidly oscillating Ap star at roughly 355 light-years (109 parsecs) from the Sun in the southern constellation of Centaurus.

HD 101065
Observation data
Epoch J2000      Equinox J2000
Constellation Centaurus
Right ascension  11h 37m 37.04110s[1]
Declination −46° 42′ 34.8754″[1]
Apparent magnitude (V) 7.996–8.020[2]
Characteristics
Spectral type F3 Ho[3]
U−B color index +0.20[4]
B−V color index +0.76[4]
Variable type roAp[2][5]
Astrometry
Radial velocity (Rv)+12.4±3[6] km/s
Proper motion (μ) RA: −46.757±0.051[1] mas/yr
Dec.: +34.024±0.047[1] mas/yr
Parallax (π)9.1920 ± 0.0343[1] mas
Distance355 ± 1 ly
(108.8 ± 0.4 pc)
Details
Mass4.0 ± 0.1[7] M☉
Radius1.90[8] R☉
Surface gravity (log g)4.2[9] cgs
Temperature6600[9] K
Metallicity [Fe/H]−2.40[10] dex
Age56.6 ± 27.9[7] Myr
Other designations
V816 Cen, CD−46°7232, HD 101065, HIP 56709, SAO 222918.[11]
Database references
SIMBADdata

Scientific history

In 1961, the Polish-Australian astronomer Antoni Przybylski discovered that this star had a peculiar spectrum that would not fit into the standard framework for stellar classification.[12][13] Przybylski's observations indicated unusually low amounts of iron and nickel in the star's spectrum, but higher amounts of unusual elements like strontium, holmium, niobium, scandium, yttrium, caesium, neodymium, praseodymium, thorium, ytterbium, and uranium. In fact, at first Przybylski doubted that iron was present in the spectrum at all. Modern work shows that the iron-group elements are somewhat below normal in abundance, but it is clear that the lanthanides and other exotic elements are highly overabundant.[5]

Przybylski's Star also contains many different short-lived actinide elements with actinium, protactinium, neptunium, plutonium, americium, curium, berkelium, californium, and einsteinium being detected. The longest-lived isotope of einsteinium has a half-life of only 472 days. Other radioactive elements discovered in this star include technetium and promethium.[14]

Compared to neighboring stars, HD 101065 has a high peculiar velocity of 23.8 ± 1.9 km/s.[7]

Theories

Because of the odd properties of this star, there are numerous theories about why the oddities occur. One such theory is that the star contains some long-lived nuclides from the island of stability (such as 298Fl) and that the observed short-lived actinides are the daughters of these progenitors, occurring in secular equilibrium with their parents.[15][16]

Properties

HD 101065 is the prototype star of the rapidly oscillating Ap star (roAP) variable star class. In 1978, it was discovered to pulsate photometrically with a period of 12.15 min.[17]

A potential companion had also been detected, a 14th magnitude star (in infrared) 8 arc seconds away. This would be a separation of nearly 1,000 AU (0.02 light years).[18] However, Gaia Data Release 2 suggests that this star lies at a distance from us of 890±90 light-years, more than twice the distance of Przybylski's Star.[19]

See also

References
  1. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "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. 5372587514128271232 Gaia DR2 record for this source at VizieR.
  2. Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1: B/gcvs. Bibcode:2009yCat....102025S.
  3. Renson, P.; Manfroid, J. (2009). "Catalogue of Ap, Hg Mn and Am stars". Astronomy and Astrophysics. 498 (3): 961. Bibcode:2009A&A...498..961R. doi:10.1051/0004-6361/200810788.
  4. Wegner, G. (1976). "On the reddening and the effective temperature of HD 101065". Monthly Notices of the Royal Astronomical Society. 177: 99–108. Bibcode:1976MNRAS.177...99W. doi:10.1093/mnras/177.1.99.
  5. Hubrig, S.; Järvinen, S. P.; Madej, J.; Bychkov, V. D.; Ilyin, I.; Schöller, M.; Bychkova, L. V. (2018). "Magnetic and pulsational variability of Przybylski's star (HD 101065)". Monthly Notices of the Royal Astronomical Society. 477 (3): 3791. Bibcode:2018MNRAS.477.3791H.
  6. Gontcharov, G. A (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065.
  7. Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410 (1): 190–200, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x
  8. Shulyak, D.; Ryabchikova, T.; Kildiyarova, R.; Kochukhov, O. (2010). "Realistic model atmosphere and revised abundances of the coolest Ap star HD 101065". Astronomy and Astrophysics. 520: A88. arXiv:1004.0246. Bibcode:2010A&A...520A..88S. doi:10.1051/0004-6361/200913750.
  9. Cowley, C. R.; Ryabchikova, T.; Kupka, F.; Bord, D. J.; Mathys, G.; Bidelman, W. P. (2000). "Abundances in Przybylski's star" (PDF). Monthly Notices of the Royal Astronomical Society. 317 (2): 299–309. Bibcode:2000MNRAS.317..299C. doi:10.1046/j.1365-8711.2000.03578.x.
  10. Przybylski, A. (January 1977). "Is iron present in the atmosphere of HD 101065". Monthly Notices of the Royal Astronomical Society. 178 (2): 71–84. Bibcode:1977MNRAS.178...71P. doi:10.1093/mnras/178.2.71.
  11. "V* V816 Cen". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2008-06-06.
  12. Przybylski, A.; Kennedy, P. Morris (August 1963). "The Spectrum of HD 101065". Publications of the Astronomical Society of the Pacific. 75 (445): 349–353. Bibcode:1963PASP...75..349P. doi:10.1086/127965.
  13. Powell, C. S.; Wright, J. (30 June 2017). "The Strangest (and Second-Strangest) Star in the Galaxy". Discover. Retrieved 10 September 2017.
  14. Gopka, V. F.; Yushchenko, A. V.; Yushchenko, V. A.; Panov, I. V.; Kim, Ch. (15 May 2008). "Identification of absorption lines of short half-life actinides in the spectrum of Przybylski's star (HD 101065)". Kinematics and Physics of Celestial Bodies. 24 (2): 89–98. Bibcode:2008KPCB...24...89G. doi:10.3103/S0884591308020049.
  15. Jason Wright (16 March 2017). "Przybylski's Star III: Neutron Stars, Unbinilium, and aliens". Retrieved 31 July 2018.
  16. V. A. Dzuba; V. V. Flambaum; J. K. Webb (2017). "Isotope shift and search for metastable superheavy elements in astrophysical data". Physical Review A. 95 (6): 062515. arXiv:1703.04250. Bibcode:2017PhRvA..95f2515D. doi:10.1103/PhysRevA.95.062515.
  17. Kurtz, D. W. (1978). "12.15 Minute Light Variations in Przybylski's Star, HD 101065". Information Bulletin on Variable Stars. 1436: 1. Bibcode:1978IBVS.1436....1K.
  18. Schöller, M.; Correia, S.; Hubrig, S.; Kurtz, D. W. (2012). "Multiplicity of rapidly oscillating Ap stars". Astronomy & Astrophysics. 545: A38. arXiv:1208.0480. Bibcode:2012A&A...545A..38S. doi:10.1051/0004-6361/201118538.
  19. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "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. 5372587509831616384 Gaia DR2 record for this source at VizieR.
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