Editing Sirius (section)

=== Apparent third star ===
{{redirect|Sirius C|the mythological star|Emme Ya}}
Since 1894, irregularities have been tentatively observed in the orbits of Sirius&nbsp;A and B with an apparent periodicity of 6–6.4&nbsp;years. A 1995 study concluded that such a companion likely exists, with a mass of roughly 0.05&nbsp;solar mass—a small [[red dwarf]] or large [[brown dwarf]], with an apparent magnitude of more than 15, and less than 3 arcseconds from Sirius A.<ref name="Benest1995"/>

In 2017, more accurate astrometric observations by the Hubble Space Telescope ruled out the existence of a stellar mass sized Sirius&nbsp;C, while still allowing a substellar mass candidate such as a lower mass [[Brown dwarf]]. The 1995 study predicted an astrometric movement of roughly 90&nbsp;[[Milliarcsecond|mas]] (0.09&nbsp;arcsecond), but Hubble was unable to detect any location anomaly to an accuracy of 5&nbsp;mas (0.005&nbsp;arcsec). This ruled out any objects orbiting Sirius&nbsp;A with more than 0.033&nbsp;solar mass (35&nbsp;Jupiter masses) in 0.5&nbsp;years, and 0.014 (15 Jupiter masses) in 2&nbsp;years. The study was also able to rule out any companions to Sirius&nbsp;B with more than 0.024&nbsp;solar mass (25&nbsp;Jupiter masses) orbiting in 0.5&nbsp;year, and 0.0095 (10&nbsp;Jupiter masses) orbiting in 1.8&nbsp;years. Effectively, there are almost certainly no additional bodies in the Sirius system larger than a small brown dwarf or large exoplanet.<ref name="siriusCruledout">{{cite news |last1=Andrew |first1=le&nbsp;Page |date=6 April 2017 |title=New Hubble observations of the Sirius system |website=drewexmachina.com |url=https://www.drewexmachina.com/2017/04/06/new-hubble-observations-of-the-sirius-system/ |access-date=21 March 2018}}</ref><ref name=bond/>