Przybylski's star

From Wikipedia, the free encyclopedia

This article or section is in need of attention from an expert on the subject.
Please help recruit one or improve this article yourself. See the talk page for details.
Please consider using {{Expert-subject}} to associate this request with a WikiProject

**HD 101065^[1]**
Observation data Epoch J2000
Constellation (pronunciation)	Centaurus
Right ascension	11^h 37^m 37.0406^s
Declination	−46° 42′ 34.882″
Apparent magnitude (V)	8.02
Characteristics
Spectral type	B5p
U-B color index	+0.20^[2]
B-V color index	+0.76^[2]
Astrometry
Radial velocity (R_v)	10.2 km/s
Proper motion (μ)	RA: −47.30 mas/yr Dec.: 33.93 mas/yr
Parallax (π)	7.95 ± 1.07^[3] mas
Distance	approx. 410 ly (approx. 130 pc)
Details
Surface gravity (log g)	4.2^[4]
Temperature	6,600^[4] K
Other designations
V* V816 Cen, CD-46°7232, HD 101065, SAO 222918, HIP 56709.

Przybylski's Star (or HD 101065) is a peculiar star that is located about 410 light years from the Sun in the constellation Centaurus.

In 1961, the Polish-Australian astronomer Antoni Przybylski (pronounced ['antɔɲi ^pʒɪ'bɪlski] roughly equivalent to "jibilski") discovered that this star had a peculiar spectrum that would not fit into the standard framework for stellar classification.^[5] Przybylski's observations indicated unusually low amounts of iron and nickel in the star's spectrum, but higher amounts of unusual elements like strontium, 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's clear that the lanthanides and other exotic elements are highly overabundant.

According to the Encyclopedia of Astrobiology, Astronomy, and Spaceflight, Przybylski's Star is...

"One of the most chemically peculiar stars known; it is named informally after its discoverer, the Polish-Australian astronomer, Antoni Przybylski....Apart from the usual lines of hydrogen and the calcium H and K, the strongest lines in HD 101065 are due to singly ionized lanthanides, presenting a spectrum similar to that of an S star, a highly evolved object whose atmosphere is enriched with recently synthesized material from deep within its interior. Yet, in other respects, HD 101065 appears to be a main sequence star or subgiant. One possibility is that it is a cool, extreme Ap star, a theory supported by the discovery of a several kilogauss magnetic field in HD 101065 similar to that of many other Ap stars. The outstanding difficulty with HD 101065 as an Ap star was that its spectrum didn't look like the others. Lines of neutral and first ionized iron are prominent in the spectra of Ap stars, and in some cases, the iron is clearly overabundant." (1)

[edit] References

^ V* V816 Cen -- Variable Star. Centre de Données astronomiques de Strasbourg. Retrieved on 2008-06-06.
^ ^a ^b Wegner, G. (1976). "On the reddening and the effective temperature of HD 101065". Monthly Notices of the Royal Astronomical Society 177: 99–108.
^ Perryman, M. A. C.; et al (1997). "The Hipparcos Catalogue". Astronomy & Astrophysics 323: L49–L52.
^ ^a ^b Cowley, C. R.; Ryabchikova, T., Kupka, F., Bord, D. J., Mathys, G., & Bidelman, W. P. (2000). "Abundances in Przybylski's star". Monthly Notices of the Royal Astronomical Society 317 (2): 299–309.
^ Przybylski, A.; Kennedy, P. M. (1963). "The Spectrum of HD 101065". Publications of the Astronomical Society of the Pacific 74 (445): 349–353.