HD 74423

A light curve for HD 74423 plotted from TESS data[1]
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Volans[2]
Right ascension 08h 40m 17.985s[3]
Declination −64° 50′ 16.84″[3]
Apparent magnitude (V) 8.58–8.66[4]
Characteristics
Spectral type A7VkA0mA0 λ Boo[5]
Apparent magnitude (B) 8.81±0.02[6]
Apparent magnitude (J) 8.065±0.020[6]
Apparent magnitude (H) 8.021±0.067[6]
Apparent magnitude (K) 7.944±0.040[6]
Variable type α2 CVn[4] or Ellipsoidal and δ Sct[7]
Astrometry
Proper motion (μ) RA: −9.719[3] mas/yr
Dec.: 11.732[3] mas/yr
Parallax (π)2.1018 ± 0.0150 mas[3]
Distance1,550 ± 10 ly
(476 ± 3 pc)
Details
primary
Mass2.1[8] M☉
Radius3.3[8] R☉
Surface gravity (log g)3.6[5] cgs
Temperature7,900[8] K
Metallicity [Fe/H]−1.0[5] dex
secondary
Mass2.0[8] M☉
Radius3.2[8] R☉
Surface gravity (log g)3.6[5] cgs
Temperature7,600[8] K
Metallicity [Fe/H]−1.0[5] dex
Age800[7] Myr
Other designations
HD 74423, CD−64°342, SAO 250298, TYC 8934-1662-1, TIC 355151781
Database references
SIMBADdata

HD 74423 is a heartbeat binary star and one component pulsates on only one hemisphere. This is caused by tidal interaction with its partner.[7] The star is located in the Volans constellation.

HD 74423 is slightly variable in brightness. It fluctuates between magnitudes 8.58 and 8.66 every 19 hours.[4] The exact variability type is unclear. It was initially found in a search for α2 Canum Venaticorum variables and assumed to be one, but has since been considered to be a δ Scuti variable.[7] The spectrum shows unusually strong absorption lines of some iron peak elements, a characteristic of λ Boötis stars. Both components are thought to show the chemical peculiarity.[7]

References

  1. ↑ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 8 December 2021.
  2. ↑ Staff (2 August 2008). "Finding the constellation which contains given sky coordinates". DJM.cc. Retrieved 31 July 2020.
  3. 1 2 3 4 5 Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  4. 1 2 3 Bernhard, K.; Hümmerich, S.; Otero, S.; Paunzen, E. (2015). "A search for photometric variability in magnetic chemically peculiar stars using ASAS-3 data". Astronomy and Astrophysics. 581: A138. arXiv:1507.01112. Bibcode:2015A&A...581A.138B. doi:10.1051/0004-6361/201526424. S2CID 54062866.
  5. 1 2 3 4 5 Gray, R. O.; Riggs, Q. S.; Koen, C.; Murphy, S. J.; Newsome, I. M.; Corbally, C. J.; Cheng, K. -P.; Neff, J. E. (2017). "The Discovery of λ Bootis Stars: The Southern Survey I". The Astronomical Journal. 154 (1): 31. Bibcode:2017AJ....154...31G. doi:10.3847/1538-3881/aa6d5e.
  6. 1 2 3 4 "HD 74423 -- Star". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 31 July 2020.
  7. 1 2 3 4 5 Handler, G.; Kurtz, D. W.; Rappaport, S. A.; Saio, H.; Fuller, J.; Jones, D.; Guo, Z.; Chowdhury, S.; Sowicka, P.; Aliçavuş, F. Kahraman; Streamer, M. (9 March 2020). "Tidally trapped pulsations in a close binary star system discovered by TESS". Nature Astronomy. 4 (7): 684–689. arXiv:2003.04071. Bibcode:2020NatAs...4..684H. doi:10.1038/s41550-020-1035-1. ISSN 2397-3366. S2CID 212634328.
  8. 1 2 3 4 5 6 Fuller, J.; Kurtz, D. W.; Handler, G.; Rappaport, S. (2020). "Tidally trapped pulsations in binary stars". Monthly Notices of the Royal Astronomical Society. 498 (4): 5730. arXiv:2008.02836. Bibcode:2020MNRAS.498.5730F. doi:10.1093/mnras/staa2376.
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