Nu Telescopii
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Telescopium |
| Right ascension | 19h 48m 01.1977s |
| Declination | −56° 21′ 45.397″ |
| Apparent magnitude (V) | 5.33±0.01 |
| Characteristics | |
| Spectral type | A7 III/IV |
| B−V color index | +0.20 |
| Astrometry | |
| Radial velocity (Rv) | −12.4±4.2 km/s |
| Proper motion (μ) | RA: +90.983 mas/yr Dec.: −137.406 mas/yr |
| Parallax (π) | 19.3152±0.0783 mas |
| Distance | 168.9 ± 0.7 ly (51.8 ± 0.2 pc) |
| Absolute magnitude (MV) | +1.86 |
| Details | |
| Mass | 1.85 M☉ |
| Radius | 1.94±0.09 R☉ |
| Luminosity | 15.6±0.1 L☉ |
| Surface gravity (log g) | 4.08+0.08 −0.07 cgs |
| Temperature | 8,199±279 K |
| Metallicity [Fe/H] | −0.02 dex |
| Age | 686 Myr |
| Other designations | |
| ν Tel, 67 G. Telescopii, CPD−56°9290, FK5 739, HD 186543, HIP 97421, HR 7510, SAO 246271 | |
| Database references | |
| SIMBAD | data |
Nu Telescopii, Latinized from ν Telescopii, is a slightly evolved star in the southern constellation Telescopium. It has an apparent visual magnitude of 5.33, allowing it to be faintly visible to the naked eye. The object is relatively close at a distance of 169 light years but is approaching the Solar System with a heliocentric radial velocity of about −12 km/s.
There hasn't been much agreement on Nu Telescopii's spectral classification. It was initially categorized as Am star, with a classification of kA4mF3IV:. This indicates that the object has the calcium K-lines of an A4 star and the metallic lines of a F3 subgiant. However, Nu Telescopii was shown not to have a peculiar spectrum and was given a class of A9 Vn, indicating that it is an A-type main-sequence star displaying broad (nebulous) absorption lines due to rapid rotation. It has since been classified as an evolved A7 star with either a blended luminosity class of a giant star or subgiant (III/IV) or only subgiant (IV).
Nu Telescopii has a mass of 1.85 M☉ and an age of 686 million years. It has 1.94 times the radius of the Sun and has an effective temperature of 8,199 K. These parameters yield a luminosity of 15.6 L☉ from its photosphere and when viewed, has a white hue. Nu Telescopii's metallicity – what astronomers dub as elements heavier than helium – is around solar level. Its motion in space matches that of the IC 2391 cluster, making it a probable member.
There is a faint magnitude 9.3 companion star at an angular separation of 102 arc seconds along a position angle of 333°, as of 2010.