![]() ![]() | |
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Virgo |
Right ascension | 14h 18m 38.251s[1] |
Declination | −18° 42′ 57.47″[1] |
Apparent magnitude (V) | 5.84 to 5.95[2] |
Characteristics | |
Evolutionary stage | Main sequence[3] |
Spectral type | A1p SrCrEu[4] or ApSi(Cr)[5] |
B−V color index | 0.013±0.006[6] |
Variable type | α2 CVn[2] |
Astrometry | |
Radial velocity (Rv) | −8.0±0.8[7] km/s |
Proper motion (μ) | RA: −52.197 mas/yr[1] Dec.: −46.004 mas/yr[1] |
Parallax (π) | 11.497 ± 0.5361 mas[1] |
Distance | 280 ± 10 ly (87 ± 4 pc) |
Absolute magnitude (MV) | 0.83[6] |
Orbit[8] | |
Period (P) | 4.4 yr |
Semi-major axis (a) | ≥161 Gm (1.08 AU) |
Eccentricity (e) | 0.21±0.01 |
Periastron epoch (T) | 2,431,475.0 JD |
Argument of periastron (ω) (secondary) | 82.4±3.4° |
Semi-amplitude (K1) (primary) | 7.5±0.5 km/s |
Details | |
Mass | 2.0±0.6[9] M☉ |
Radius | 1.95[10] R☉ |
Luminosity | 42.0±8.3[9] L☉ |
Surface gravity (log g) | 4.05±0.10[9] cgs |
Temperature | 9,850±250[9] K |
Rotation | 9.29558±0.00006 d[9] |
Rotational velocity (v sin i) | 18[11] km/s |
Age | 234[9] Myr |
Other designations | |
236 G. Virginis, CS Vir, BD−18°3789, FK5 1369, GC 19295, HD 125248, HIP 69929, HR 5355, SAO 158481, PPM 228604[12] | |
Database references | |
SIMBAD | data |
HD 125248 is a binary star[13] system in the equatorial constellation of Virgo. It has the variable star designation CS Virginis, while HD 125248 is the designation from the Henry Draper Catalogue. This system is dimly visible to the naked eye as a point of light with an apparent visual magnitude that ranges from 5.84 down to 5.95.[2] It is located at a distance of approximately 280 light years from the Sun based on parallax measurements,[1] but is drifting closer with a heliocentric radial velocity of −8 km/s.[7]
This star was classified as peculiar with spectral type A0p in the Henry Draper Catalogue, published 1918–1924. This class was based on the strength of a pair of lines of ionized silicon in its stellar spectrum. In 1931, W. W. Morgan discovered that the spectrum of the star varied over a period of several days. In particular, the lines of ionized chromium and europium varied considerably in intensity, ranging from strong to very faint. This variation shares similarities to those of α2 Canum Venaticorum. The two sets of lines vary in the opposite direction from each other, so that the chromium lines were minimum when the europium lines were maximized, and vice versa.[14] In 1947, A. J. Deutsch found a period of 9.295 days for the variation.[15]
H. W. Babcock examined the star using Coudé spectrograms in 1947, finding a general magnetic field with a strength of around 5,500 Gauss at the poles. At the time, that was the strongest magnetic field that had been observed in a star. He noticed that the magnetic field was variable, and it showed the opposite polarity when the lines of europium were at a minimum compared to when they were at the maximum.[16] Subsequent observations showed the period and amplitude of the variation to be stable over time.[8] In 1950, D. W. N. Stibbs first proposed an 'oblique rotator model' to explain the properties of this star,[17] in which its magnetic field is locked at an angle to the axis of rotation.[9]
The star displays radial velocity variations that suggest it is a single-lined spectroscopic binary with a period of 4.4 years and an orbital eccentricity of 0.21.[8] The visible component has a stellar classification of A1p SrCrEu,[4] which indicates this is a magnetic peculiar Ap star with prominent abundance anomalies of strontium, chromium, and europium in its atmosphere. It has double the mass and nearly twice the radius of the Sun.[9][10] The star is an estimated 234 million years old and is spinning with a rotation rate of 9.3 days.[9] It is radiating 42 times the luminosity of the Sun from its photosphere at an effective temperature of 9,850 K.[9]
This is an Alpha2 Canum Venaticorum variable star with a brightness that is modulated by its rotation.[2] Magnetic Doppler imaging of the star suggests the magnetic field deviates strongly from a simple dipole geometry.[9]
GaiaEDR3
was invoked but never defined (see the help page).Samus_et_al_2017
was invoked but never defined (see the help page).ozuyar2018
was invoked but never defined (see the help page).Renson_Manfroid_2009
was invoked but never defined (see the help page).Houk_Smith-Moore_1978
was invoked but never defined (see the help page).Anderson_Francis_2012
was invoked but never defined (see the help page).Gontcharov2006
was invoked but never defined (see the help page).Hockey1969
was invoked but never defined (see the help page).Rusomarov_et_al_2016
was invoked but never defined (see the help page).Shulyak_et_al_2014
was invoked but never defined (see the help page).Royer_et_al_2002
was invoked but never defined (see the help page).SIMBAD
was invoked but never defined (see the help page).Eggleton_Tokovinin_2008
was invoked but never defined (see the help page).Morgan1931
was invoked but never defined (see the help page).Deutsch1947
was invoked but never defined (see the help page).Babcock1947
was invoked but never defined (see the help page).Stibbs1950
was invoked but never defined (see the help page).HIPCurve
was invoked but never defined (see the help page).