With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Jack Black was the main character in School of Rock.
text_B: Cataclysmic variable stars -LRB- CV -RRB- are stars which irregularly increase in brightness by a large factor , then drop back down to a quiescent state .. They were initially called novae , from the Latin ` new ' , since ones with an outburst brightness visible to the naked eye and an invisible quiescent brightness appeared as new stars in the sky .. Cataclysmic variable stars are binary stars that consist of two components ; a white dwarf primary , and a mass transferring secondary .. white dwarf. white dwarf. The stars are so close to each other that the gravity of the white dwarf distorts the secondary , and the white dwarf accretes matter from the companion .. white dwarf. white dwarf. Therefore , the secondary is often referred to as the donor star .. The infalling matter , which is usually rich in hydrogen , forms in most cases an accretion disc around the white dwarf .. white dwarf. white dwarf. hydrogen. hydrogen. accretion disc. accretion disc. Strong UV and X-ray emission is often seen from the accretion disc , powered by the loss of gravitational potential energy from the infalling material .. accretion disc. accretion disc. X-ray. X-ray. Material at the inner edge of disc falls onto the surface of the white dwarf primary .. white dwarf. white dwarf. A classical nova outburst occurs when the density and temperature at the bottom of the accumulated hydrogen layer rise high enough to ignite runaway hydrogen fusion reactions , which rapidly convert the hydrogen layer to helium .. nova. nova. hydrogen. hydrogen. density. density. temperature. temperature. runaway. thermal runaway. hydrogen fusion. nuclear fusion. helium. helium. If the accretion process continues long enough to bring the white dwarf close to the Chandrasekhar limit , the increasing interior density may ignite runaway carbon fusion and trigger a Type Ia supernova explosion , which would completely destroy the white dwarf .. white dwarf. white dwarf. density. density. runaway. thermal runaway. Chandrasekhar limit. Chandrasekhar limit. runaway carbon fusion. Carbon detonation. Type Ia supernova. Type Ia supernova. The accretion disc may be prone to an instability leading to dwarf nova outbursts , when the outer portion of the disc changes from a cool , dull mode to a hotter , brighter mode for a time , before reverting to the cool mode .. nova. nova. accretion disc. accretion disc. instability. instability. dwarf nova. dwarf nova. Dwarf novae can recur on a timescale of days to decades .
not_related.