HD 100453
Young binary in constellation Centaurus
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HD 100453 is a binary star system which lies in the constellation Centaurus about 350 light years away from the Sun and is a member of the open cluster Scorpius–Centaurus association.
An unusual structure around HD 100453 uncovered by ESO's SPHERE, a planet-hunting instrument installed on the Very Large Telescope in Chile[1] | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Centaurus[2] |
| Right ascension | 11h 33m 05.5766s[3] |
| Declination | −54° 19′ 28.547″[3] |
| Apparent magnitude (V) | 7.79[4] |
| Characteristics | |
| Evolutionary stage | Herbig Ae/Be star[5] |
| Spectral type | A9Ve[6] |
| Apparent magnitude (g) | 7.735[3] |
| Apparent magnitude (B) | 8.07[5] |
| Apparent magnitude (R) | 7.63[5] |
| Apparent magnitude (K) | 5.60[5] |
| Astrometry | |
| Radial velocity (Rv) | 14.597[3] km/s |
| Proper motion (μ) | RA: −36.96±0.02 mas/yr[3] Dec.: −5.86±0.02 mas/yr[3] |
| Parallax (π) | 9.636±0.022 mas[3] |
| Distance | 338.5 ± 0.8 ly (103.8 ± 0.2 pc) |
| Absolute magnitude (MV) | +2.39[2] |
| Orbit[7] | |
| Semi-major axis (a) | 207 au |
| Eccentricity (e) | 0.32 |
| Inclination (i) | 49° |
| Longitude of the node (Ω) | 47° |
| Periastron epoch (T) | 1790 |
| Argument of periastron (ω) (secondary) | 18° |
| Details | |
| A | |
| Mass | 1.60+0.05 −0.04[8] M☉ |
| Radius | 1.57 ± 0.11[8][a] R☉ |
| Luminosity | 6.31±0.14[8] L☉ |
| Surface gravity (log g) | 4.47±0.05[8] cgs |
| Temperature | 7,250±250[5][8] K |
| Metallicity [Fe/H] | −0.1±0.1[8] dex |
| Rotation | 0.92±0.10[8] days |
| Rotational velocity (v sin i) | 50±3[8] km/s |
| Age | 19.28+0.70 −0.68[8] Myr |
| B | |
| Mass | 0.20±0.04[7] M☉ |
| Radius | 0.77[7][b] R☉ |
| Luminosity | 0.06[7] L☉ |
| Temperature | 3,250[7] K |
| Other designations | |
| CD−53°4102, HIP 56354, TYC 8617-1438-1, GSC 08617-01438, 2MASS J11330559-5419285[9] | |
| Database references | |
| SIMBAD | data |
Components
The apparent magnitudes of the visible components A and B are 7.8 and 15.9 respectively. The primary is a Herbig Ae/Be star, which is young but no longer accreting mass.[10] The secondary is an M4 class red dwarf star at the projected separation 120 AU from the primary.[11]
Circumstellar disks
The primary star is surrounded by two dust disks, separated by a gap. The disks are orbiting in different planes, misaligned by 72 degrees. The disk misalignment may be caused by a suspected superjovian planet orbiting within the gap,[5] roughly 15–20 AU from the primary.[12] The outer disk has a 2-arm spiral structure caused by the outer stellar companion HD 100453B.[11] The outer disk is rather massive at 0.0174 M☉,[13] but is significantly depleted in gas, with a gas-to-dust mass ratio of no more than 4:1.[10]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination (°) |
Radius |
|---|---|---|---|---|---|---|
| inner disk | 0.315[5] AU | 46.05+0.88 −0.92 [5]° |
— | |||
| outer disk | 45[11] AU | 33.80+0.77 −0.72[5]° |
— | |||
The gas present in the disks is unusually depleted in nitrogen and hydrogen-bearing compounds and enriched in carbon monoxide.[14] Molecular hydrogen was not detected.[15] Solid silicate material present in the disks shows good crystallinity, with reduced amounts of amorphous material.[16]
No disks were detected around the companion star HD 100453B, with the upper limit on the amount of dust around it being 0.03 M🜨.[17]
Notes
- Calculated, using the Stefan-Boltzmann law and the star's effective temperature and luminosity, with respect to the solar nominal effective temperature of 5,772 K:
- Calculated, using the Stefan-Boltzmann law and the star's effective temperature and luminosity, with respect to the solar nominal effective temperature of 5,772 K:
