BD Phoenicis

BD Phoenicis

A blue band light curve for BD Phoenicis, adapted from Koen et al. (2003)[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Phoenix
Right ascension 01h 50m 54.44s[2]
Declination −50° 12′ 22.09″[2]
Apparent magnitude (V) 5.90 – 5.94[3]
Characteristics
Spectral type A1Va λ Boo[4]
Variable type δ Scuti[3]
Astrometry
Radial velocity (Rv)3.0[5] km/s
Proper motion (μ) RA: -47.85[2] mas/yr
Dec.: -3.70[2] mas/yr
Parallax (π)12.7260 ± 0.0447 mas[2]
Distance256.3 ± 0.9 ly
(78.6 ± 0.3 pc)
Absolute magnitude (MV)1.5 ± 0.1[1]
Details
Mass2.02 ± 0.04[1] M☉
Luminosity20.5 ± 0.34[6] L☉
Surface gravity (log g)3.91 ± 0.08[1] cgs
Temperature7,818 ± 38[6] K
Rotational velocity (v sin i)120 ± 5 [1] km/s
Age813+38
−89[1] Myr
Other designations
BD Phe, CD−50°514, HD 11413, HIP 8593, HR 541, SAO 232542[7]
Database references
SIMBADdata

BD Phoenicis is a variable star in the constellation of Phoenix. From parallax measurements by the Gaia spacecraft, it is located at a distance of 256 light-years (78 parsecs) from Earth.[2] Its absolute magnitude is calculated at 1.5.[1]

Description

BD Phoenicis is a Lambda Boötis star, an uncommon type of peculiar stars that have very low abundances of iron-peak elements. In particular, BD Phoenicis has near-solar carbon and oxygen content, but its iron abundance is only 4% of the solar value.[1] BD Phoenicis is also a pulsating variable of Delta Scuti type, varying its apparent magnitude between 5.90 and 5.94.[3] A study of its light curve detected seven pulsation periods that range from 50 to 84 minutes, the strongest one having a period of 57 minutes and an amplitude of 9 milli-magnitudes. Pulsations are common among Lambda Boötis stars and seem to be more common than normal main sequence stars of the same spectral type.[1]

BD Phoenicis is an A-type main-sequence star with a spectral type of A1Va.[4] Stellar evolution models indicate it contains double the solar mass and an age of about 800 million years—having completed 83% of its main sequence lifetime.[1] It is radiating 21 times the Sun's luminosity from its photosphere at an effective temperature of 7800 K.[6] BD Phoenicis has a composite spectra that indicate it is a binary star, but nothing is known about its companion.[8][6]

Observations by the Herschel Space Observatory have detected an infrared excess from BD Phoenicis, indicating that there is a debris disk in the system. By modeling the emission as a black body, it is estimated that the dust has a temperature of 55±2 K and is at a distance of 118±10 au from the star. The existence of debris disks is possibly related to the Lambda Boötis phenomenon.[6]

References

  1. ^ a b c d e f g h i j Koen, C.; Paunzen, E.; Van Wyk, F.; Marang, F.; Chernyshova, I. V.; Andrievsky, S. M. (2003). "The pulsational characteristics of the λ Bootis type star BD Phe (HD 11413)". Monthly Notices of the Royal Astronomical Society. 338 (4): 931. Bibcode:2003MNRAS.338..931K. doi:10.1046/j.1365-8711.2003.06149.x.
  2. ^ a b c d e f Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  3. ^ a b c 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.
  4. ^ a b Gray, R. O.; Garrison, R. F. (1987). "The Early A-Type Stars: Refined MK Classification, Confrontation with Stroemgren Photometry, and the Effects of Rotation". The Astrophysical Journal Supplement Series. 65: 581. Bibcode:1987ApJS...65..581G. doi:10.1086/191237.
  5. ^ Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID 119231169.
  6. ^ a b c d e Draper, Z. H.; Matthews, B. C.; Kennedy, G. M.; Wyatt, M. C.; Venn, K. A.; Sibthorpe, B. (2016). "IR excesses around nearby Lambda Boo stars are caused by debris discs rather than ISM bow waves". Monthly Notices of the Royal Astronomical Society. 456 (1): 459. arXiv:1511.05919. Bibcode:2016MNRAS.456..459D. doi:10.1093/mnras/stv2696. S2CID 118343020.
  7. ^ "BD Phe". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 31 January 2019.
  8. ^ Faraggiana, R.; Bonifacio, P.; Caffau, E.; Gerbaldi, M.; Nonino, M. (2004). "λ Bootis stars with composite spectra". Astronomy and Astrophysics. 425 (2): 615–626. arXiv:astro-ph/0406265. Bibcode:2004A&A...425..615F. doi:10.1051/0004-6361:20040216. S2CID 117998682.