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Sun, 14 Aug 2016 - R Ursae Majoris is approaching maximum

The Mira type variable R Ursae Majoris is currently approaching its 2016 maximum.

R UMa has an average gap between maxima of 302 days - approx 10 months. As the light curve below shows, the most recent maximum occurred in November 2015.

This maximum was fainter than average, with R UMa only reaching about mag 8.0, more than half a magnitude below its average peak (some can become as bright as mag 6.7). Following a minimum at around mag 12.5 during spring 2016, R UMa had by early August brightened to around mag 8.1.

Maximum brightness is expected to occur in late August or early September.

You can follow the brightness changes of R UMa using this chart, which has north at the top and is approx 7 degrees by 4 degrees. Comparison stars are labelled with their magnitudes (decimal points omitted so, for example, '76' labels a comparison star of magnitude 7.6).

More information about R UMa, including a wider angle chart showing the location of R UMa relative to the main stars of the 'Plough', can be found  here

 

Added by: Tracie Heywood