Astronomy:HD 74423

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Short description: Variable star in the constellation Volans
HD 74423
HD74423LightCurve.png
A light curve for HD 74423 plotted from TESS data[1]
Observation data
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[3] mas
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
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. https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html. 
  2. Staff (2 August 2008). "Finding the constellation which contains given sky coordinates". DJM.cc. http://djm.cc/constellation.html. Retrieved 31 July 2020. 
  3. 3.0 3.1 3.2 3.3 3.4 Brown, A. G. A. (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics 649: A1. doi:10.1051/0004-6361/202039657. Bibcode2021A&A...649A...1G.  Gaia EDR3 record for this source at VizieR.
  4. 4.0 4.1 4.2 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. doi:10.1051/0004-6361/201526424. Bibcode2015A&A...581A.138B. 
  5. 5.0 5.1 5.2 5.3 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. doi:10.3847/1538-3881/aa6d5e. Bibcode2017AJ....154...31G. 
  6. 6.0 6.1 6.2 6.3 "HD 74423 -- Star". SIMBAD. Centre de Données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-id?Ident=HD+74423. Retrieved 31 July 2020. 
  7. 7.0 7.1 7.2 7.3 7.4 Handler, G.; Kurtz, D. W.; Rappaport, S. A.; Saio, H.; Fuller, J.; Jones, D.; Guo, Z.; Chowdhury, S. et al. (2020-03-09). "Tidally trapped pulsations in a close binary star system discovered by TESS". Nature Astronomy 4 (7): 684–689. doi:10.1038/s41550-020-1035-1. ISSN 2397-3366. Bibcode2020NatAs...4..684H. 
  8. 8.0 8.1 8.2 8.3 8.4 8.5 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. doi:10.1093/mnras/staa2376. Bibcode2020MNRAS.498.5730F. 

External links