The spelling of the word "sandage" can be explained using the IPA phonetic transcription. The first syllable "san" is pronounced as /sænd/, which represents the "s" sound followed by the short "a" vowel sound and the "n" sound. The second syllable "dage" is pronounced as /deɪdʒ/, representing the long "a" vowel sound followed by the "j" sound, which is the voiced palato-alveolar affricate. The word "sandage" is commonly used in the field of astronomy to refer to a system for measuring the brightness of stars.