AE Ursae Majoris

A light curve for AE Ursae Majoris, plotted from TESS data[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Ursa Major
Right ascension 09h 36m 53.155s[2]
Declination +44° 04 00.40[2]
Apparent magnitude (V) 10.86 to 11.52[3]
Characteristics
Evolutionary stage subgiant[4]
Spectral type A9[4]
Variable type SX Phe(?)[3]
Astrometry
Radial velocity (Rv)150±27[4] km/s
Proper motion (μ) RA: −15.755 mas/yr[2]
Dec.: −12.650 mas/yr[2]
Parallax (π)1.3593 ± 0.0332 mas[2]
Distance2,400 ± 60 ly
(740 ± 20 pc)
Details[4]
Mass1.805±0.055 M
Radius2.367±0.046 R
Luminosity24.0+2.8
2.5
 L
Surface gravity (log g)3.9543±0.0044 cgs
Temperature8,357+195
190
 K
Metallicity [Fe/H]−0.32±0.23 dex
Age1.055±0.095 Gyr
Other designations
AE UMa, HIP 47181, 2MASS J09365316+4404004[5]
Database references
SIMBADdata

AE Ursae Majoris is a star in the northern circumpolar constellation of Ursa Major, abbreviated AE UMa. It is a variable star that ranges in brightness from a peak apparent visual magnitude of 10.86 down to 11.52.[3] The distance to this star is approximately 2,400 light years based on parallax measurements.[2]

The variability of this star was announced by E. Geyer and associates in 1955.[6] V. P. Tsesevich in 1973 found it to be a dwarf cepheid with a period of 0.086017 days, and he noticed it showed amplitude variations in the light curve.[7] In 1974, B. Szeidl determined a secondary period of 0.066529 days,[8] while P. Broglia and P. Conconi found a beat period of 0.294 days.[9] It belonged to a group of high amplitude, double mode Delta Scuti variables that included SX Phoenicis,[10] and by 1995 it was classified as a SX Phoenicis variable and a possible halo object. However, E. Hintz and associates in 1997 found strong evidence against this classification.[7][4]

In 2001, the overtone pulsation period of this star was shown to change at the rate of −7.3×10−8 y−1.[11] In addition, possible sudden jumps in the period have been observed, a property it has in common with VZ Cancri.[12] With an estimated mass 1.8 times that of the Sun and an age of a billion years, it is an evolved star that has left the main sequence and is generating energy on a hydrogen-burning shell surrounding a helium core. The metallicity suggests it is a population I Delta Scuti variable. Currently it is crossing the Hertzsprung gap.[4]

References

  1. MAST: Barbara A. Mikulski Archive for Space Telescopes, Space Telescope Science Institute, retrieved 22 September 2022.
  2. 1 2 3 4 5 6 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.
  3. 1 2 3 Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
  4. 1 2 3 4 5 6 Niu, Jia-Shu; et al. (May 2017), "AE Ursae Majoris - a δ Scuti star in the Hertzsprung Gap", Monthly Notices of the Royal Astronomical Society, 467 (3): 3122–3139, arXiv:1304.3772, Bibcode:2017MNRAS.467.3122N, doi:10.1093/mnras/stx125.
  5. "AE UMa". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2022-09-16.
  6. Geyer, E.; et al. (1955), "Kleine Veroeffentl", Remeis Observatory Bamberg, p. 9.
  7. 1 2 Hintz, E.; et al. (October 1997), "Time-Series Ensemble Photometry of SX Phoenicis Stars. II. AE Ursae Majoris", Publications of the Astronomical Society of the Pacific, 109: 1073–1076, Bibcode:1997PASP..109.1073H, doi:10.1086/133977, S2CID 122988714.
  8. Szeidl, B. (June 1974), "The Secondary Period of AE UMa", Information Bulletin on Variable Stars, 903: 1, Bibcode:1974IBVS..903....1S.
  9. Broglia, P.; Conconi, P. (September 1974), "On the Beat Period of AE UMa", Information Bulletin on Variable Stars, 923: 1, Bibcode:1974IBVS..923....1B.
  10. Andreasen, G. K. (May 1983), "Delta Scuti variables. II. Comparisons of theoretical evolution sequences with observational data.", Astronomy and Astrophysics, 121: 250–258, Bibcode:1983A&A...121..250A.
  11. Szeidl, B. (July 2001), "The small period change of the Delta Scuti star AE UMa", Communications in Asteroseismology, 140: 56, Bibcode:2001CoAst.140...56S.
  12. Coates, D. W.; Landes, H. (April 2008), "The beat-curve approach applied to AE UMa", Communications in Asteroseismology, 153: 8–16, Bibcode:2008CoAst.153....8C, doi:10.1553/cia_153s8.

Further reading

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