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. Indeed, this star is the prototype (archetype in practice) for DZ white dwarfs. Physical models of white dwarfs used by today's astrophysicists show that elements with mass greater than helium would sink, all things being equal, below the photosphere, leaving hydrogen and helium to be visible in the spectrum; for heavier elements to appear here requires a recent external source. It is unlikely that they were obtained from the interstellar medium, since that is primarily composed of hydrogen and helium. Instead, the surface of the star was likely strewn with circumstellar material, such as from the remains of one or more rocky, terrestrial planets.