or reddish in appearance. Epsilon Telescopii is a binary star system: the brighter component, Epsilon Telescopii A, is an orange giant of spectral type K0III with an apparent magnitude of +4.52, while the 13th magnitude companion, Epsilon Telescopii B, is 21 arcseconds away from the primary, and just visible with a 15 cm aperture telescope on a dark night. The system is 417 light-years away. Iota Telescopii and HD 169405—magnitude 5 orange giants of spectral types K0III and K0.5III respectively—make up the quartet. They are around 370 and 497 light-years away from the Sun respectively. Another ageing star, Kappa Telescopii is a yellow giant with a spectral type G9III and apparent magnitude of 5.18. Around 1.87 billion years old, this star of around 1.6 solar masses has swollen to 11 times the Sun's diameter. It is approximately 293 light-years from Earth, and is another optical double. Xi Telescopii is an irregular variable star that ranges between magnitudes 4.89 and 4.94. Located 1079 light-years distant, it is a red giant of spectral type M2III that has a diameter around 5.6 times the Sun's, and a luminosity around 2973 times that of the Sun. Another irregular variable, RX Telescopii is a red supergiant that varies between magnitudes 6.45 and 7.47, just visible to the unaided eye under good viewing conditions. BL Telescopii is an Algol-like eclipsing binary system that varies between apparent magnitudes 7.09 and 9.08 over a period of just over 778 days (2 years 48 days). The primary is a yellow supergiant that is itself intrinsically variable. Dipping from its baseline magnitude of 9.6 to 16.5, RS Telescopii is a rare R Coronae Borealis variable—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. The dimming is thought to be caused by carbon dust expelled by the star. As of 2012, four dimmings have been observed. PV Telescopii is a class B-type (blue) extreme helium star that is the prototype of a class of variables known as PV Telescopii variables. First discovered in 1952, it was found to have a very low level of hydrogen. One theory of its origin is that it is the result of a merger between a helium- and a carbon-oxygen white dwarf. If the combined mass does not exceed the Chandrasekhar limit, the former will accrete onto the