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Guide to R Serpentis

A Mira type variable near the 'head' of Serpens, that currently reaches its annual peak around the middle of the year.

R Serpentis is a red giant star whose brightness variations are primarily related to pulsations in its outer layers.

As can be seen from the above light curve, the rise to maximum is much steeper than the fade afterwards and some maxima are brighter than others.

Extreme brightness range 5.7 - 14.4
More typical range 6.9 - 13.4
Period of variation 357 days  (8 days shorter than a year)
Frequency of observation Worth checking a few times per month
Observe using 50mm binoculars will suffice when near maxima. Larger binoculars will be required as it fades. A telescope will be required to follow it all the way down to minimum
Visibility Can be observed all year round, but is visible only in the morning sky from December to February
Dates of Maxima early July 2017, late June 2018

The finder charts which follow have north at the top and show the location of R Serpentis.

The first shows a wider view showing its location relative to Arcturus and Corona Borealis:

The second chart, which is approx 7 degrees by 5 degrees,  shows the area close to R Ser in more detail.

If you wish to follow R Serpentis all the way down to minimum, suitable comparison stars can be found on this BAA VSS chart .  Note that this latter chart has south at the top