IPA: /ˌboʊləˈmɛtrɪkli/
KK: /bɑlˈoʊməˌtrɪkli/
In a way that relates to measuring the total energy of radiation, typically using a device called a bolometer.
The researchers measured the star's brightness bolometrically to get a complete picture of its energy output.
Bolometrically → It is formed from "bolometer" (from Greek "bōlos" meaning a mass or a lump, and "metron" meaning measure) and the suffix "-ically" (meaning in a manner relating to). The word "bolometrically" refers to the manner of measuring radiant energy using a bolometer.
Think of measuring a 'mass' ('bōlos') of energy with a 'meter' ('metron') — that's how bolometrically relates to measuring energy.