 Debris disk surrounding young star HD 15115 Credit:NASA, ESA, G. Schneider (University of Arizona), and the HST/GO 12228 Team | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cetus |
| Right ascension | 02h 26m 16.24577s[1] |
| Declination | +06° 17′ 33.1880″[1] |
| Apparent magnitude (V) | 6.76[2] |
| Characteristics | |
| Spectral type | F4IV[3] or F2V[4] |
| U−Bcolor index | −0.03[2] |
| B−Vcolor index | +0.39[2] |
| Astrometry | |
| Radial velocity (Rv) | 0.81±0.12[5] km/s |
| Proper motion (μ) | RA: +88.030[1]mas/yr Dec.: -50.515[1]mas/yr |
| Parallax (π) | 20.4065±0.0418 mas[1] |
| Distance | 159.8 ± 0.3 ly (49.0 ± 0.1 pc) |
| Details | |
| Mass | 1.19[6] M☉ |
| Radius | 1.39±0.06[1] R☉ |
| Luminosity | 3.74±0.01[1] L☉ |
| Surface gravity (log g) | 4.30[6] cgs |
| Temperature | 6,811+148 −152[1] K |
| Metallicity[Fe/H] | 0.96[6] dex |
| Rotational velocity (v sin i) | 89.8[7] km/s |
| Age | 500[8] Myr |
| Other designations | |
| BD+05°338,HD 15115,HIP 11360,SAO 110532,WDS J02263+0618A[9] | |
| Database references | |
| SIMBAD | data |
HD 15115 is a single[10]star in theequatorialconstellation ofCetus. It is readily visible in binoculars or a small telescope, but is considered too dim to be seen with the naked eye at anapparent visual magnitude of 6.76.[2] The distance to this object is 160 light years based onparallax,[1] and it is slowly drifting further away at the rate of about 1 km/s.[5] It has been proposed as a member of theBeta Pictoris moving group[11] or theTucana-Horologium association of co-moving stars; there is some ambiguity as to its true membership.[12]
This object has astellar classification of F4IV,[3] suggesting it is an agingsubgiant star that has exhausted the supply of hydrogen at itscore. MacGregor and associates (2015) instead classify it as a youngF-type main-sequence star with a class of F2V.[4] Age estimates give a value of 500[8] million years, while membership in the β Pictoris moving group would indicate an age of around21±4 million.[4] It has 1.19[6] times themass of the Sun, 1.39[1] times theSun's radius, and has a relatively high rate of spin with aprojected rotational velocity of 90 km/s.[7] The star is radiating 3.74[1] times theluminosity of the Sun from itsphotosphere at aneffective temperature of 6,811 K.[1] Itsmetallicity – the abundance of elements other than hydrogen and helium – is nearly the same as in the Sun.[6]
HD 15115 was shown to have an asymmetricdebris disk surrounding it, which is being viewed nearly edge-on. The reason for the asymmetry is thought to be either the gravitational pull of a passing star (HIP 12545), anexoplanet, or interaction with the localinterstellar medium.[13] A magnitude 11.35visual companion lies at anangular separation of12.6″ along aposition angle of 195°, as of 2015.[11]
