This star had been captured on a plate taken November 11, 1896 for the Carte du Ciel Catalog of Toulouse and it showed an apparent magnitude of 12.3.

[17] These are stars that have an unusually low absolute magnitude for their spectral class, lying well below the main sequence on the Hertzsprung–Russell diagram of stellar temperature vs.

[18] The high mass density of white dwarfs was demonstrated in 1925 by American astronomer Walter Adams when he measured the gravitational redshift of Sirius B as 21 km/s.

[19] In 1926, British astrophysicist Ralph Fowler used the new theory of quantum mechanics to show that these stars are supported by electron gas in a degenerate state.

He showed that the latter no longer occurs within a white dwarf, and calculated the internal temperature of van Maanen 2 as 6 × 106 K. He gave a preliminary age estimate of 1011/A years, where A is the mean atomic weight of the nuclei in the star.

Van Maanen 2 is 14.1 light-years (4.3 parsecs) from the Sun in the constellation Pisces, about 2° to the south of the star Delta Piscium,[26] with a relatively high proper motion of 2.978″ annually along a position angle of 155.538°.

As all white dwarfs steadily radiate away their heat over time, this temperature can be used to estimate its age, thought to be around 3 billion years.

[8] The stellar classification of Van Maanen 2 is DZ8, having a helium atmosphere with a significant presence of heavier elements in its spectrum – what astronomers term metals.

In the case of van Maanen 2, observations at a wavelength of 24 μm do not show the infrared excess that might be generated by a dusty disk.

[40] No potential proper motion companions have been identified between an angular separation of 5 arcseconds out to 10°, ruling out objects with a mass of 75 MJ or greater.