[ peer-ee-uh d-loo-muh-nos-i-tee ]
/ ˈpɪər i ədˌlu məˈnɒs ɪ ti /
the relationship between the period of light variation and of the absolute magnitude of Cepheid variable stars.
What Do A.M. And P.M. Stand For?Most English speakers know that a.m. refers to the hours from midnight and noon, and p.m. to the hours from noon and midnight. But what do these ubiquitous abbreviations stand for? The term we associate with the morning, a.m., is an abbreviation the Latin phrase ante merīdiem meaning “before midday”; p.m. is an abbreviation of post merīdiem, meaning—you guessed it—“after midday.” These two terms help …
Verb Tenses: Past, Future, And Even PerfectThe six basic verb tenses are past, present, future, past perfect, present perfect, and future perfect. Verb tenses identify the time period when an action occurs. They also show relationships between events that happen at different times. The simple tenses (past, present, and future) are the most basic forms. Simple Tenses Present tense describes events happening now. It’s also useful for describing a direct action …
Origin of period-luminosity relation
First recorded in 1945–50
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019