Hd 101065 - An Astronomical Enigma

1976 ◽  
Vol 32 ◽  
pp. 351-355
Author(s):  
A. Przybylski
Keyword(s):  
Rare Earths ◽  
Effective Temperature ◽  
Peculiar Star ◽  
Testing Ground ◽  
Ap Stars

SummaryHD 101065 is a very peculiar star whose spectrum is dominated entirely by the numerous lines of the rare earths. The only other metals seen in the spectrum are strontium, yttrium, zirconium and barium and traces of calcium.The effective temperature of the star is 6075° ± 200°K or about 1000°K lower than that of the coolest Ap stars known to date.HD 101065 is a suitable testing ground for the theories on the formation of Ap stars. The absence of “normal” elements in the atmosphere of the star puts stringent limitations on the choice of the available theories.

Search for Light Variations of HD 101065

1977 ◽  
Vol 3 (2) ◽  
pp. 143-144 ◽  
Author(s):  
A. Przybylski
Keyword(s):  
Rare Earths ◽  
Effective Temperature ◽  
Critical Examination ◽  
Iron Group ◽  
Peculiar Star ◽  
Positive Identification ◽  
The Subject

The eighth magnitude star HD 101065 is an extremely peculiar star with a unique spectrum characterized by numerous strong lines of the rare earths and the absence, or at least a remarkable weakening, of the lines of the iron group (Cowley et al. 1977). Besides the lanthanides only yttrium, zirconium, calcium and barium are definitely present in the atmosphere in substantial quantities. The evidence for the presence of lithium and strontium is subject to some doubt since these elements are represented only by one or two reasonably strong lines, which is insufficient for a positive identification in a spectrum as complex as that of HD 101065. The evidence for the presence of other elements is the subject of a critical examination in a recent paper by Cowley et al. (1977). The effective temperature of the star is about 6100 K (Przybylski, 1977) which is substantially lower than the temperature of any known Ap star. However, the effective temperature of HD 101065 is still subject to controversy (Wegner, 1976).

scholarly journals Abundances in Magnetic Ap Stars

1993 ◽  
Vol 138 ◽  
pp. 18-25
Author(s):  
Charles R. Cowley
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Rare Earths ◽  
Chemical Separation ◽  
Abundance Anomalies ◽  
Ap Stars ◽  
Spatial Inhomogeneities

AbstractThe spatial inhomogeneities, Zeeman broadening, and extreme abundance anomalies have thus far prevented definitive analyses of magnetic CP stars. Nevertheless, the abundance anomalies are so large that many of them have been known for decades. Abundance excesses of iron-peak elements of factors of 10 to 100 are common. Relative abundances on the iron peak are not constant. The lines of vanadium and nickel are often weak, and these elements may even be deficient in some stars. In spitè of the large variations, the odd-even effect persists; there is only minor evidence that chemical separation has perturbed the nuclear pattern. The lanthanide rare earths can have excesses of 100 to 1000 or even more in extreme cases. For these elements there is some evidence of fractionation. The actinide rare earth elements uranium and thorium are weakly (but surely!) present in a few of the magnetic CP stars: the best case is HR 465.

Infrared observations and the effective temperature of the peculiar star HD 101065

1975 ◽  
Vol 87 ◽  
pp. 439 ◽  
Author(s):  
A. R. Hyland ◽  
J. R. Mould ◽  
G. Robinson ◽  
J. A. Thomas
Keyword(s):  
Effective Temperature ◽  
Peculiar Star ◽  
Infrared Observations

scholarly journals HD 101065 – Przybylski’s Star: A Most Peculiar Star

2002 ◽  
Vol 187 ◽  
pp. 351-364
Author(s):  
D.W. Kurtz
Keyword(s):  
Current Understanding ◽  
Peculiar Star ◽  
Ap Stars

AbstractThe story of HD 101065, Przybylski’s star, is one of a forty-year controversy over the nature of what is arguably the most peculiar star in the sky, a controversy that is only now being resolved fully. Our current understanding is that HD 101065 is the coolest (Teff ≈ 7400 K) and the most peculiar of the Ap SrCrEu stars. The existence of this most peculiar star, and other Ap stars, has been the source of some very interesting stellar astrophysics with applications far wider than the understanding of just the stars themselves.

scholarly journals Hipparcos Luminosities and Asteroseismology

2002 ◽  
Vol 12 ◽  
pp. 694-697
Author(s):  
Timothy R. Bedding
Keyword(s):  
Internal Structure ◽  
Effective Temperature ◽  
Resonant Frequencies ◽  
Evolutionary State ◽  
Hipparcos Catalogue ◽  
Oscillation Frequencies ◽  
Ap Stars

AbstractAsteroseismology involves using the resonant frequencies of a star to infer details about its internal structure and evolutionary state. Large efforts have been made and continue to be made to measure oscillation frequencies with both ground- and space-based telescopes, with typical precisions of one part in 103–104. However, oscillation frequencies are most useful when accompanied by accurate measurements of the more traditional stellar parameters such as luminosity and effective temperature. The Hipparcos catalogue provides luminosities with precisions of a few percent or better for many oscillating stars. I briefly discuss the importance of Hipparcos measurements for interpreting asteroseismic data on three types of oscillating stars: δ Scuti variables, rapidly oscillating Ap stars and solar-like stars.

scholarly journals The Spectral Type of HD 101065

1976 ◽  
Vol 72 ◽  
pp. 135-141
Author(s):  
A. Przybylski
Keyword(s):  
Spectral Type ◽  
Rare Earths ◽  
Effective Temperature ◽  
Type Star ◽  
Spectral Classification ◽  
The Continuum

The eighth magnitude star HD 101065 has an extremely peculiar spectrum dominated by numerous lines of the rare earths and lacking the lines of ‘normal’ elements, such as iron peak elements and lighter elements. For this reason it cannot be fitted into the adopted framework of spectral classification. The spectral type of this star can be defined only by fixing its effective temperature, which is 6040 ± 100 K. However, because of the extremely high blanketing the temperature of the continuum is about 450 K higher. This means that HD 101065 is a late F type star.

The Photometric Properties of the Ap Stars

1976 ◽  
Vol 32 ◽  
pp. 365-377 ◽  
Author(s):  
B. Hauck
Keyword(s):  
Physical Properties ◽  
Ap Stars

The Ap stars are numerous - the photometric systems tool It would be very tedious to review in detail all that which is in the literature concerning the photometry of the Ap stars. In my opinion it is necessary to examine the problem of the photometric properties of the Ap stars by considering first of all the possibility of deriving some physical properties for the Ap stars, or of detecting new ones. My talk today is prepared in this spirit. The classification by means of photoelectric photometric systems is at the present time very well established for many systems, such as UBV, uvbyβ, Vilnius, Geneva and DDO systems. Details and methods of classification can be found in Golay (1974) or in the proceedings of the Albany Colloquium edited by Philip and Hayes (1975).

Variation of Heavy Element Lines in the Ap Stars

1976 ◽  
Vol 32 ◽  
pp. 311-320 ◽  
Author(s):  
I.A. Aslanov ◽  
Yu. S. Rustamov ◽  
M. Kowalski
Keyword(s):  
Heavy Element ◽  
Ap Stars

SummaryLines of U II were found in the spectrograms of the Ap stars HR 465, 17 Com A and HD 224801. Pm II lines were found in HR 465. These lines vary in intensity in HR 465 with a period of 6h41m, in 17 Com A of 71m, and in HD 224801 of 6h.

Peculiarity Parameters

1976 ◽  
Vol 32 ◽  
pp. 233-254
Author(s):  
H. M. Maitzen
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Theoretical Work ◽  
Observational Evidence ◽  
Rotator Model ◽  
Peculiar Behaviour ◽  
Field Spectrum ◽  
Oblique Rotator ◽  
Ap Stars ◽  
The Way

Ap stars are peculiar in many aspects. During this century astronomers have been trying to collect data about these and have found a confusing variety of peculiar behaviour even from star to star that Struve stated in 1942 that at least we know that these phenomena are not supernatural. A real push to start deeper theoretical work on Ap stars was given by an additional observational evidence, namely the discovery of magnetic fields on these stars by Babcock (1947). This originated the concept that magnetic fields are the cause for spectroscopic and photometric peculiarities. Great leaps for the astronomical mankind were the Oblique Rotator model by Stibbs (1950) and Deutsch (1954), which by the way provided mathematical tools for the later handling pulsar geometries, anti the discovery of phase coincidence of the extrema of magnetic field, spectrum and photometric variations (e.g. Jarzebowski, 1960).

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