Alpha Telescopii
 Location of α Telescopii (circled) |
|
| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Telescopium |
| Right ascension | 18h 26m 58.41604s[1] |
| Declination | –45° 58′ 06.4498″[1] |
| Apparent magnitude (V) | 3.51[2] |
| Characteristics | |
| Spectral type | B3 IV[3] |
| U−B color index | −0.64[2] |
| B−V color index | −0.17[2] |
| Variable type | SPB[4] |
| Astrometry | |
| Radial velocity (Rv) | −0.2[5] km/s |
| Proper motion (μ) | RA: −16.95[1] mas/yr Dec.: −53.09[1] mas/yr |
| Parallax (π) | 11.74 ± 0.17[1] mas |
| Distance | 278 ± 4 ly (85 ± 1 pc) |
| Details | |
| Mass | 5.2 ± 0.4[4] M☉ |
| Radius | 3.3 ± 0.5[4] R☉ |
| Luminosity | 794[4] L☉ |
| Surface gravity (log g) | 4.12 ± 0.20[4] cgs |
| Temperature | 16,700 ± 800[4] K |
| Rotational velocity (v sin i) | 14 ± 8[4] km/s |
| Age | 24.1 ± 7.5[6] Myr |
| Other designations | |
Alpha Telescopii (α Tel, α Telescopii) is the brightest star in the constellation Telescopium, with an apparent visual magnitude of 3.5.[2] Ptolemy included it in constellation Corona Australis, but it was moved to Telescopium when that constellation was created by Nicolas Louis de Lacaille in the 18th century.[8] Parallax measurements put it at a distance of 278 light-years (85 parsecs) from Earth.
This star is much larger than the Sun, with an estimated 5.2±0.4 times the mass and 3.3±0.5 times the radius.[4] The spectrum of the star matches a stellar classification of B3 IV,[3] where the luminosity class of 'IV' indicates this is a subgiant star that has nearly exhausted the supply of hydrogen at its core and is evolving away from the main sequence. Alpha Telescopii is a bright star that is radiating nearly 800 times the Sun's luminosity. This energy is being emitted from the star's outer envelope at an effective temperature of around 16,700 K,[4] giving it the characteristic blue-white hue of a B-type star.[9]
This is possibly a type of variable star known as a slowly pulsating B-type star. It has a longitudinal magnetic field with a mean strength of –233 ± 43 G.[4] A projected stellar rotation velocity of about 14 km s−1 is considered low for a star of this type,[4] which may indicate it is being viewed from nearly pole-on.[10]
References
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- ↑ 2.0 2.1 2.2 2.3 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 3.0 3.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
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