|Fomalhaut,(Alpha Piscis Austrini) is an A3 main-sequence star|
"Heic0821f" by Davide De Martin
Licensed under Public Domain via Commons
Mu Lyrae (μ Lyr, μ Lyrae) is main-sequence dwarf star with apparent magnitude 5.12. It belongs to the spectral class A0IV. Located around 439 light-years distant, it shines with a luminosity approximately 125 times that of the Sun and has a surface temperature of 8190 K.
The star has the traditional name Alathfar, from the Arabic الأظفر al-’uz̧fur "the talons (of the swooping eagle)", a name it shares with Eta Lyrae (usually spelled with d instead of th: Aladfar).
Let me repeat: luminosity of 125 times that of the Sun.
These are among the more common naked eye stars and are white or bluish-white.
They have strong hydrogen lines, at a maximum by A0, and also lines of ionized metals (Fe II, Mg II, Si II) at a maximum at A5. The presence of Ca II lines is notably strengthening by this point.
About 1 in 160 (0.625%) of the main-sequence stars in the solar neighborhood are A-type stars.
- A0Van: Gamma Ursae Majoris
- A0Va: Vega
- A0Ib: Eta Leonis
- A0Ia: HD 21389
- A2Ia: Deneb
- A3Va: Fomalhaut