HD 124448

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Stern
HD 124448
AladinLite
Observation
dates equinox :  J2000.0 , epoch : J2000.0
Constellation centaur
Right ascension 14 h 14 m 58.63 s
declination −46 ° 17 ′ 19.3 ″
Apparent brightness (+9.98) mag
Typing
B − V color index (−0.09) 
U − B color index (−0.80) 
Spectral class B3p
Variable star type PVTELII 
Astrometry
Radial velocity (−67.0 ± 2.4) km / s
parallax (0.57 ± 0.13)  mas
distance (5,700)  ly
(1,750)  pc
Proper movement 
Rec. Share: (−6.89 ± 0.15)  mas / a
Dec. portion: (−0.09 ± 0.20)  mas / a
Physical Properties
Other names
and catalog entries
Cordoba Survey CD −45 ° 9033
Henry Draper Catalog HD 124448 [1]
Hipparcos catalog HIP 69619 [2]
SAO catalog SAO 224792 [3]
Tycho catalog TYC 8264-3162-1 [4]
2MASS catalog 2MASS J14145863-4617192 [5]
Other names V821 Centauri

HD 124448 ( V821 Centauri ) is a star about 5000  light years away . It was recognized in 1942 by the astronomer Daniel Popper as the first representative of the extreme helium stars , making it one of the peculiar stars . The specialty of these stars is that no hydrogen can be detected in their spectra , but strong lines of helium , carbon and oxygen , which make these stars resemble the white dwarfs . In contrast to white dwarfs, however, they are still active and are accordingly much larger and more luminous.

This star shows significantly lower pulsations than the extreme helium star PV Telescopii and is therefore not necessarily counted among the pulsation-variable stars .

New measurements from the Gaia probe indicate with a high degree of probability that the star is significantly further away than initially thought. Evaluations of the Hipparcos data by van Leeuwen in 2007 would have indicated a distance of 1500 light years, the more recent data in Gaia DR2 indicate a distance of over 5000 light years with a still high margin of error.

Individual evidence

  1. ↑ a b c d e f V821 Cen. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed August 26, 2018 .
  2. ↑ a b C.S. Jeffrey, AE Lynas-Gray: Photometry of the extreme helium star HD 124448 . In: MNRAS . 242, 1990, pp. 6-9. bibcode : 1990MNRAS.242 .... 6Y .
  3. ↑ a b V0821 Cen. In: VSX. AAVSO, accessed August 26, 2018 .
  4. ↑ The star in VizieR. In: Hipparcos catalog . Retrieved August 26, 2018 .
  5. ↑ The star in VizieR. In: Gaia DR2 . Retrieved August 26, 2018 .