| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Telescopium |
| Right ascension | 18h 23m 14.66203s [2] |
| Declination | −56° 37′ 44.1401″ [2] |
| Apparent magnitude (V) | 9.30 [3] (9.24 - 9.40) [4] |
| Characteristics | |
| Spectral type | B5p [5] |
| U−B color index | −0.60 [3] |
| B−V color index | −0.10 [3] |
| Variable type | PV Tel [4] |
| Astrometry | |
| Radial velocity (Rv) | −169 [6] km/s |
| Proper motion (μ) | RA: −1.086 [2] mas/yr Dec.: −7.705 [2] mas/yr |
| Parallax (π) | 0.1162±0.0449 mas [2] |
| Distance | 23,000 ly (7,100+1,400 −2,000 [1] pc) |
| Absolute magnitude (MV) | −4.4 [7] |
| Details | |
| Mass | 0.94 [8] M☉ |
| Radius | 27.20+4.09 −7.26 [1] R☉ |
| Luminosity | 24,000+8,600 −9,900 [1] L☉ |
| Surface gravity (log g) | 1.60±0.25 [1] cgs |
| Temperature | 13,750±400 [1] K |
| Metallicity [Fe/H] | −0.15 [9] dex |
| Other designations | |
| PV Tel, CD−56°7300, HD 168476, HIP 90099, SAO 245434, 2MASS J18231466-5637441, AAVSO 1814-56 [10] | |
| Database references | |
| SIMBAD | data |
PV Telescopii, also known as HD 168476, is a variable star in the southern constellation of Telescopium. It is too dim to be visible to the naked eye, having an apparent visual magnitude that has been measured varying from 9.24 down to 9.40. [4] The star is the prototype of a class of objects called PV Telescopii variables. It is located at an estimated distance of approximately 23 kilolight-years (7.1 kiloparsecs ) from the Sun, [1] but is drifting closer with a radial velocity of −169 km/s. [6]
In 1973, Arlo Udell Landolt published an article suggesting that the star, then known as HD 168476, might vary in brightness on a timedcale of a decade. [11] In 1980, Helen Joan Walker and David Kilkenny confirmed that the star's brightness varies. [12] It was given its variable star designation, PV Telescopii, in 1981. [13]
This is an extreme helium star that shows a highly-processed atmosphere. [14] It is a blue-white hued B-type supergiant star with a peculiar spectrum that has "weak hydrogen lines and enhanced lines of He and C". [15] [16] This object may be a late thermal pulse post-AGB star or the result of a merger of two white dwarf stars. [8] [17] The star shows radial velocity changes thought to be due to radial pulsations caused by a strange mode instability. [8] It shows variations over a few days, 8–10 days being typically quoted. [8] [17] Despite a mass thought to be less than the Sun, [8] it is actually around 24,000 times more luminous. [1]
