Guide To R Lyrae

R Lyrae is a naked eye variable, easily found in the constellation of Lyra. R Lyrae varies between an extreme range of magnitudes 3.9 and 5.0 with a period of 46 days. Like all semi-regular stars, it can be hard to determine the exact period of variability. Several periods have been suggested for R Lyrae, including 64, 378 and 1000 days. However, 46 days is the most widely observed period.

R Lyrae is a very red star and this can make it hard to observe. One problem facing variable star observers is the Purkinje Effect. This is when red light builds-up on the retina, so as you stare at a red star, the star appears to get brighter and brighter. When observing red stars with the naked eye, it is best to take brief glimpses and not too stare at the star for any length of time. Mist and moonlight can also affect your ability to estimate red stars accurately; so it is best to observe red stars when the sky is dark and clear.

Extreme brightness range 3.9 – 5.0
More typical range 3.8 – 4.4
Period of variation 46 days
Frequency of observation Once a week
Observe using Naked eye – if you have a reasonably dark observing site. Otherwise use 40mm or 50mm binoculars.
Visibility Best observed between May and November