AE Ursae Majoris

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]

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]
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
AE UMa, HIP 47181, 2MASS J09365316+4404004[5]
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]