Xi Telescopii
Star in the constellation Telescopium
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Xi Telescopii, Latinized from ξ Telescopii, is a solitary[7] star in the southern constellation of Telescopium. It is visible to the naked eye, with an apparent visual magnitude of +4.9. Based upon an annual parallax shift of 3.02 mas as measured from Earth,[3] it is located approximately 1,100 light-years from the Sun.
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Telescopium[2] |
| Right ascension | 20h 07m 23.15599s[3] |
| Declination | −52° 52′ 50.8490″[3] |
| Apparent magnitude (V) | +4.89 – 4.94[4] |
| Characteristics | |
| Evolutionary stage | red giant branch[5] |
| Spectral type | K5 III[6] or M1 IIab[7] |
| U−B color index | +1.90[8] |
| B−V color index | +1.61[8] |
| Variable type | LB:[4] |
| Astrometry | |
| Radial velocity (Rv) | +36.0[9] km/s |
| Proper motion (μ) | RA: −12.98[3] mas/yr Dec.: +7.50[3] mas/yr |
| Parallax (π) | 3.02±0.35 mas[3] |
| Distance | approx. 1,100 ly (approx. 330 pc) |
| Absolute magnitude (MV) | −2.64[2] |
| Details | |
| Mass | 6.6[5] M☉ |
| Radius | 134[5] R☉ |
| Luminosity | 3,413[5] L☉ |
| Surface gravity (log g) | 0.99[5] cgs |
| Temperature | 4,529[5] K |
| Other designations | |
| ξ Tel, CPD−53°9794, FK5 755, HD 190421, HIP 99120, HR 7673, SAO 246443[10] | |
| Database references | |
| SIMBAD | data |
This is an evolved star with a stellar classification of K5 III[6] or M1 IIab,[7] indicating it is a giant or bright giant star. This is a variable star tentatively classified as a slow irregular-type variable with a brightness that varies between magnitude +4.89 and +4.94.[4] Koen and Eyer examined the Hipparcos data for this star, and found that it varied periodically, with a period of 12.36 days, and an amplitude of 0.0083 magnitudes.[11] With around 134 times the Sun's radius, it shines with a luminosity approximately 3,400 times that of the Sun and has a surface temperature of 4,529 K.[5]