Rotation and Luminosity Budgets of a White-Dwarf Merger Product from a 0.9 plus 0.6 Solar-Mass Pair

This paper examines the merger of white dwarfs of 0.90 and 0.60 solar masses in contact, producing a rapidly rotating remnant of about 1.42 solar masses after modest mass loss, with a radius near 0.009 solar radii. Using published input values and the standard energy comparison between envelope binding and orbital release, the calculation addresses the specific budget that decides the outcome for this pairing. The headline results are: omega_fraction_of_breakup = 2.837; spin_period_if_all_retained_min = 0.04; breakup_period_min = 0.12. The method, inputs and limitations are stated in full so that any reader can reproduce or rescale every number from the deposited calculation script. A white-dwarf merger converts orbital angular momentum into spin, heat and expelled material in proportions that decide what the remnant looks like for the next billion years. Agreement and disagreement with published values for this class are reported at their actual size, and the conclusions are limited to what the budget arithmetic supports.