R Aquarii

R Aquarii

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R Aquarii is an unusual red giant variable star in the constellation Aquarius. It is classified as a symbiotic variable because it interacts with a white dwarf star. AAVSO light observations from 1928 to the present show a wide variation from magnitude 11 to 6.8. In 1938 Edwin Hubble detected expansion of the surrounding nebula in comparative image plates. Current observations attribute the expansion to violent eruptions spewing enormous amounts of material from the close gravitational interaction of the two stars. The interacting system is of special interest to astronomers because it is a rare case wherein the smaller and much older white dwarf star is absorbing fresh material and heavier elements such as nitrogen and carbon from it dieing neighbor.


This 5 hours exposure was taken through a 16” Newtonian at 4,200mm. Rambunctious seeing degraded detail sharpness considerably. An earlier and less magnified version taken with a D7000 DSLR can be found here.

Date Imaged       :

November 19, 2013

Lens       :

N16 f/10.4

Camera       :


Exposure       :

5 hours

Filter       :

LHaGB 24:18:16:18 x 4 minutes

Mount       :

Losmandy Titan

Location       :

Stardust Observatory, Baguio