G240-72 - White Dwarf
This white dwarf with the designation "G240-72" is located just 20.26 light-years from Earth in the constellation Draco, making it the seventh closest dwarf star to us.
With a mass of 0.81 solar masses, it has a diameter of 13,700 kilometers and is therefore only slightly larger than our Earth. Because it is already very old at an age of
5.7 billion years, it has been cooling down for even half an eternity and is therefore only 5,700 Kelvin hot. This results in a very low luminosity of 1/12,000 suns. It has
a helium atmosphere and it takes over 100 years for a single rotation.
----------------------------------------------------------------------------------------------------------------------------------------------
In my 20" f/3 telescope, the white dwarf is a faint object that is easy to see at a magnification of 270x. Due to its high proper motion, the star has moved considerably
further in the last few decades, which can be seen very clearly in the eyepiece if you take a DSS printout. An exciting thing! :)
