HD 28843

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HD 28843
Eridanus constellation map.svg
Red circle.svg
Location of HD 28843 (circled)
Observation data
Epoch J2000.0        Equinox J2000.0
Constellation Eridanus
Right ascension 04h 32m 37.55373s [1]
Declination −03° 12′ 34.3448″ [1]
Apparent magnitude  (V)5.70 - 5.84 [2]
Characteristics
Spectral type B9III [3]
U−B color index −0.55 [4]
B−V color index −0.14 [4]
Variable type SX Arietis [5]
Astrometry
Radial velocity (Rv)18±7 [3]  km/s
Proper motion (μ)RA: 18.227±0.068 [1]   mas/yr
Dec.: −16.177±0.054 [1]   mas/yr
Parallax (π)5.8958 ± 0.0608  mas [1]
Distance 553 ± 6  ly
(170 ± 2  pc)
Absolute magnitude  (MV)−0.7 [6]
Details
Mass 4.20±0.6 [7]   M☉
Radius 3.4 [1]   R☉
Luminosity 324+57
−48 [7]   L☉
Surface gravity (log g)3.86 [1]   cgs
Temperature 14800±200 [7]   K
Metallicity [Fe/H]−0.166 [8]   dex
Rotation 1.37381±0.00001  d [9]
Rotational velocity (v sin i)91 [7]  km/s
Other designations
DZ Eri, HR  1441, HIP  21192, SAO  131279 [10]
Database references
SIMBAD data
A light curve for DZ Eridani, plotted from TESS data DZEriLightCurve.png
A light curve for DZ Eridani, plotted from TESS data

HD 28843, also known as HR 1441 and DZ Eridani, is a star about 550 light years from the Earth, in the constellation Eridanus. [1] It is a 5th magnitude star, so it will be faintly visible to the naked eye of an observer far from city lights. It is a variable star, whose brightness varies slightly from 5.70 to 5.84 during its 1.374 day rotation period. [2] [9] It is a member of the μ Tauri Association, a group of young stars within the larger Cassiopeia-Taurus Structure. [3]

In 1969 Mercedes Jaschek et al. determined that HD 28843 is a helium-weak star, based on its B-V color index being bluer (more negative) than would be expected for a star with its spectral type. [12] In 1977, Robert Davis reported that the star has an overabundance of silicon. [13] It is classified as a chemically peculiar star. [14]

Henning Jorgensen et al. reported that HD 28843 was a "suspected variable star" in 1971. [15] The variability of the star was firmly established in 1977 by Holger Pedersen and Bjarne Thomsen, during a spectroscopic and photometric study of helium weak and helium strong stars. They determined its period to be 1.374±0.006 days. [16] In 1978 the star was given the variable star designation DZ Eridani. [17]

Ermanno Borra et al. reported in 1983 the detection of the magnetic field of HD 28843, and estimated its strength to be a few hundred gauss. [18] Later data from the International Ultraviolet Explorer implied a field strength of 250 gauss. [19]

M. Farthmann et al. reported in 1994 that high spectral resolution observations of the 4471Å spectral line of neutral helium can be explained if HD 28843 has two helium-enriched circular "caps" separated by a region with a dramatically lower helium abundance. [20]

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References

  1. 1 2 3 4 5 6 7 8 Vallenari, A.; et al. (Gaia Collaboration) (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics . arXiv: 2208.00211 . doi: 10.1051/0004-6361/202243940 . Gaia DR3 record for this source at VizieR.
  2. 1 2 Manfroid, J.; Mathys, G. (July 1984). "On the Photometric Variations of HD 28843 and HD 29009" (PDF). Information Bulletin on Variable Stars. 2551. Bibcode:1984IBVS.2551....1M . Retrieved 4 March 2023.
  3. 1 2 3 Gagné, Jonathan; David, Trevor J.; Mamajek, Eric E.; Mann, Andrew W.; Faherty, Jacqueline K.; Bédard, Antoine (November 2020). "The μ Tau Association: A 60 Myr Old Coeval Group at 150 pc from the Sun". The Astrophysical Journal. 903 (2): 96. Bibcode:2020ApJ...903...96G. doi: 10.3847/1538-4357/abb77e .
  4. 1 2 Feinstein, A. (April 1978). "Photoelectric measures of hydrogen lines in helium-weak stars". Revista Mexicana de Astronomía y Astrofísica. 2: 331–337. Bibcode:1978RMxAA...2..331F.
  5. ↑ Samus', N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (2017). "General catalogue of variable stars: Version GCVS 5.1". Astronomy Reports. 61 (1): 80. Bibcode:2017ARep...61...80S. doi: 10.1134/S1063772917010085 . S2CID   125853869.
  6. ↑ Eggen, O. J. (April 1977). "Is star formation bimodal? II. The nearest early-type stars". Publications of the Astronomical Society of the Pacific. 89: 187–204. Bibcode:1977PASP...89..187E. doi: 10.1086/130099 .
  7. 1 2 3 4 Shultz, M. E.; Owocki, S. P.; ud-Doula, A.; Biswas, A.; Bohlender, D.; Chandra, P.; Das, B.; David-Uraz, A.; Khalack, V.; Kochukhov, O.; Landstreet, J. D.; Leto, P.; Monin, D.; Neiner, C.; Rivinius, Th.; Wade, G. A. (June 2022). "MOBSTER - VI. The crucial influence of rotation on the radio magnetospheres of hot stars". Monthly Notices of the Royal Astronomical Society. 513 (1): 1429–1448. arXiv: 2201.05512 . Bibcode:2022MNRAS.513.1429S. doi:10.1093/mnras/stac136.
  8. ↑ Cardiel, Nicolás; Zamorano, Jaime; Carrasco, Josep Manel; Masana, Eduard; Bará, Salvador; González, Rafael; Izquierdo, Jaime; Pascual, Sergio; Sánchez de Miguel, Alejandro (23 July 2021). "RGB photometric calibration of 15 million Gaia stars". Monthly Notices of the Royal Astronomical Society. 507 (1): 318–329. arXiv: 2107.08734 . Bibcode:2021MNRAS.507..318C. doi: 10.1093/mnras/stab2124 . eISSN   1365-2966. ISSN   0035-8711.
  9. 1 2 Waelkens, C. (July 1985). "Photometric variations and period determination of eight southern CP stars". Astronomy and Astrophysics Supplement Series. 61: 127–139. Bibcode:1985A&AS...61..127W.
  10. ↑ "HD 28843 -- Rotating Variable". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2023-03-03.
  11. ↑ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 3 March 2023.
  12. ↑ Jaschek, Mercedes; Jaschek, Carlos; Arnal, Marcelo (October 1969). "Helium-Weak Stars". Publications of the Astronomical Society of the Pacific. 81 (482): 650–656. Bibcode:1969PASP...81..650J. doi: 10.1086/128832 .
  13. ↑ Davis, R. J. (April 1977). "Spectral classification and U, B, V, Hbeta photometry". Astrophysical Journal. 213: 105–110. Bibcode:1977ApJ...213..105D. doi:10.1086/155134.
  14. ↑ Bonsack, W. K.; Dyck, H. M. (September 1983). "Infrared colors of the chemically peculiar stars of the upper main sequence". Astronomy and Astrophysics. 125: 29–33. Bibcode:1983A&A...125...29B.
  15. ↑ Jørgensen, H. E.; Johansen, K. T.; Olsen, E. H. (May 1971). "Variability of A and F main sequence stars". Astronomy and Astrophysics. 12: 223–231. Bibcode:1971A&A....12..223J.
  16. ↑ Pedersen, H.; Thomsen, B. (October 1977). "Spectrum and photometric variability of He-weak and He-strong stars". Astronomy and Astrophysics Supplement Series. 30: 11–25. Bibcode:1977A&AS...30...11P.
  17. ↑ Kholopov, P. N.; Kukarkina, N. P.; Perova, N. B. (April 1979). "64th Name-List of Variable Stars" (PDF). Information Bulletin on Variable Stars. 1581. Bibcode:1979IBVS.1581....1K . Retrieved 25 February 2023.
  18. ↑ Borra, E. F.; Landstreet, J. D.; Thompson, I. (September 1983). "The magnetic fields of the helium-weak B stars". Astrophysical Journal Supplement Series. 53: 151–167. Bibcode:1983ApJS...53..151B. doi:10.1086/190889.
  19. ↑ Brown, D. N.; Shore, S. N.; Barker, P. K.; Sonneborn, G. (December 1984). "Magnetospheres and winds in the helium weak stars: observations of C IV in upper main sequence CP stars". NASA Conference Publication. 2349: 487–490. Bibcode:1984NASCP2349..487B.
  20. ↑ Farthmann, M.; Dreizler, S.; Heber, U.; Hunger, K. (November 1994). "Stratification of helium in the photospheres of the helium-weak stars HD 28843 and HD 49333". Astronomy and Astrophysics. 291: 919–927. Bibcode:1994A&A...291..919F.
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