What spectral characteristic is a key identifier for A-type stars?
Answer
The prominence of their hydrogen spectral lines
A key characteristic of A-type stars is that their hydrogen spectral lines reach peak strength in their temperature range of $7,500 ext{ K}$ to $10,000 ext{ K}$.
Related Questions
What physical property is fundamental for astronomers sorting stars into the O, B, A, F, G, K, M sequence?Which sequence correctly lists the main spectral classes from hottest to coolest?What temperature range generally defines O-type stars, the hottest class?What spectral characteristic is a key identifier for A-type stars?Which spectral class includes our Sun, and what is its typical color?What feature dominates the spectra of M-type stars?How are finer distinctions made within the OBAFGKM sequence (e.g., between G0 and G5)?What characteristic spectral signature is observed in B-type stars?What is the primary purpose of the Yerkes luminosity classification system, designated by Roman numerals?What did Annie Jump Cannon originally use as a proxy for temperature when formalizing the spectral classification system?