A-type main-sequence star
| A-type main-sequence star | |
|---|---|
Vega, the second brightest star in the northern celestial hemisphere, is an A-type main-sequence star (field of view approx. 1°). | |
| Characteristics | |
| Type | Class of moderate-large main sequence star. |
| Mass range | 1.63–2.33 M☉ |
| Temperature | 7400–9700 K |
| Average luminosity | 8–38 L☉ |
| External links | |
| Media category | |
| Q471805 | |
An A-type main-sequence star is a main-sequence (core hydrogen burning) star of spectral type A. The spectral luminosity class is V. These stars have spectra defined by strong hydrogen Balmer absorption lines. They measure between 1.7 and 2.1 solar masses (M☉), have surface temperatures between 7,600 and 10,000 K, and live for about a quarter of the lifetime of the Sun. Bright and nearby examples are Altair (A7), Sirius A (A1), and Vega (A0). A-type stars do not have convective zones and thus are not expected to harbor magnetic dynamos. As a consequence, because they do not have strong stellar winds; they lack a means to generate X-ray emission.