Editing Triangulum Australe (section)

===Variable stars===
Triangulum Australe contains several [[cepheid variable]]s, all of which are too faint to be seen with the naked eye:{{sfn|Klepešta|Rükl|1974|pp=248–49}} [[R Trianguli Australis]] ranges from apparent magnitude 6.4 to 6.9 over a period of 3.389 days, [[S Trianguli Australis]] varies from magnitude 6.1 to 6.8 over 6.323 days, and [[U Trianguli Australis]]' brightness changes from 7.5 to 8.3 over 2.568 days.{{sfn|Inglis|2004|p=119}} All three are yellow-white giants of spectral type F7Ib/II,{{sfn|SIMBAD R Trianguli Australis}} F8II,{{sfn|SIMBAD S Trianguli Australis}} and F8Ib/II respectively.{{sfn|SIMBAD U Trianguli Australis}} [[RT Trianguli Australis]] is an unusual cepheid variable which shows strong [[absorption band]]s in [[molecule|molecular]] fragments of [[Diatomic carbon|C<sub>2</sub>]], [[methylidyne radical|'''⫶'''CH]] and [[cyano radical|'''⋅'''CN]], and has been classified as a carbon cepheid of spectral type R. It varies between magnitudes 9.2 and 9.97 over 1.95 days.{{sfn|Wallerstein et al. 2000}} Lying nearby Gamma, [[X Trianguli Australis]] is a variable [[carbon star]] with an average magnitude of 5.63.{{sfn|SIMBAD X Trianguli Australis}} It has two periods of around 385 and 455 days, and is of spectral type C5, 5(Nb).{{sfn|Tabur|Bedding|2009}}

[[EK Trianguli Australis]], a [[dwarf nova]] of the SU Ursae Majoris type, was first noticed in 1978 and officially described in 1980.{{sfn|Hassall|1985}} It consists of a [[white dwarf]] and a donor star which orbit each other every 1.5 hours.{{sfn|Mennickent|Arenas|1998}} The white dwarf sucks matter from the other star onto an [[accretion disc]] and periodically erupts, reaching magnitude 11.2 in [[superoutburst]]s, 12.1 in normal outbursts and remaining at magnitude 16.7 when quiet.{{sfn|Gänsicke et al.|1997}} [[NR Trianguli Australis]] was a slow nova which peaked at magnitude 8.4 in April 2008, before fading to magnitude 12.4 by September of that year.{{sfn|Bianciardi|2009}}