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]
| 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] |
| Distance | 2,400 ± 60 ly (740 ± 20 pc) |
| Details[4] | |
| Mass | 1.805±0.055 M☉ |
| Radius | 2.367±0.046 R☉ |
| Luminosity | 24.0+2.8 −2.5 L☉ |
| Surface gravity (log g) | 3.9543±0.0044 cgs |
| Temperature | 8,357+195 −190 K |
| Metallicity [Fe/H] | −0.32±0.23 dex |
| Age | 1.055±0.095 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
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
Further reading
- Pena, J. H.; et al. (November 2016), "Pulsational stability of the SX Phe star AE UMa", Information Bulletin on Variable Stars, 6186 (6186): 1, Bibcode:2016IBVS.6186....1P, doi:10.22444/IBVS.6186.
- Zhou, A. -Y. (July 2001), "Period and amplitude variations in the high-amplitude delta Scuti star AE Ursae Majoris", Astronomy and Astrophysics, 374: 235–242, Bibcode:2001A&A...374..235Z, doi:10.1051/0004-6361:20010722.
- Pejcha, O.; et al. (May 2001), "Times of Maximum Light for AE Ursae Majoris", Information Bulletin on Variable Stars, 5080: 1, Bibcode:2001IBVS.5080....1P.
- Pócs, M. D.; Szeidl, B. (March 2001), "Stability of pulsation of the double-mode high-amplitude δ Scuti star AE Ursae Majoris", Astronomy and Astrophysics, 368 (3): 880–887, Bibcode:2001A&A...368..880P, doi:10.1051/0004-6361:20010043, S2CID 54946458.
- Szeidl, B.; Viraghalmy, G. (September 2000), "UBVRI Photometry of AE Ursae Maioris at Konkoly Observatory (1974-1998)", Communications of the Konkoly Observatory, 98: 303, Bibcode:2000CoKon..98..303S.
- Broglia, P.; Conconi, P. (November 1975), "Beat phenomena in the dwarf cepheid AE UMa", Astronomy and Astrophysics Supplement Series, 22: 243–261, Bibcode:1975A&AS...22..243B.