| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Telescopium |
| Right ascension | 18h 18m 51.2224s [2] |
| Declination | −46° 32′ 53.427″ [2] |
| Apparent magnitude (V) | 10.67 [3] |
| Characteristics | |
| Spectral type | R0 |
| B−V color index | 2.100±0.510 [3] |
| Variable type | R CrB [4] |
| Astrometry | |
| Radial velocity (Rv) | −3.0 [3] km/s |
| Proper motion (μ) | RA: −2.730 [2] mas/yr Dec.: −6.670 [2] mas/yr |
| Parallax (π) | 0.1732±0.0166 mas [2] |
| Distance | 19,000 ± 2,000 ly (5,800 ± 600 pc) |
| Details | |
| Radius | 73 [5] R☉ |
| Luminosity | 288 (at max) [6] L☉ |
| Surface gravity (log g) | 1.0 [7] cgs |
| Temperature | 5,800 [6] K |
| Other designations | |
| RS Tel, CD−46°12279, HIP 89739 [8] | |
| Database references | |
| SIMBAD | data |
RS Telescopii, abbreviated RS Tel, is a variable star in the southern constellation of Telescopium. It is a dim star with an apparent visual magnitude of 10.67, [3] which is much too faint to be visible without a telescope. The variability of this star was discovered by Evelyn F. Leland and announced by Edward C. Pickering in 1910. [9] It was first studied by Cecilia H. Payne in 1928 at the Harvard College Observatory. [10] [11]
This is an R-type carbon star with a class of R0. [12] RS Tel is a typical R Coronae Borealis variable [10] —an extremely hydrogen-deficient supergiant thought to have arisen as the result of the merger of two white dwarfs; fewer than 100 have been discovered as of 2012. [4] It has under 55% [13] the mass of the Sun and an effective temperature of around 5,800 K. [6] The spectrum of the star shows anomalously weak lines of hydrogen, with strong lines of C2, CN, and neutral carbon. [14]
RS Tel has a maximum magnitude of 9.6 and a minimum magnitude 16.5. [15] The star undergoes large, random variations in brightness on a time scale of thousands of days with no apparent periodicity. [16] The star is surrounded by a circumstellar shell of dust which radiating an infrared excess. [16]
