Sirius' name

[s_shortsnout]

No: HPFGUIDX 56423

I don't know how many of you already know this, but I just found 
this out and thought it quite interesting.
Now we all know that Sirius' name derives from Sirius, the "dog 
star", the brightest star in the sky and in the constellation Canis 
Major (one of Orion's hunting dogs).However, Sirius is actually a 
binary star. The more prominent of the two, Sirius A, is a white 
star with a small oval orbit around Sirius B, "the pup", a black 
dwarf that is undetectable to the human eye. So I guess Sirius's 
name is actually derives from Sirius B, the Black Dwarf, or "the 
Pup", which makes sense because his name is "Sirius Black" and his 
animagus form makes him undetactable to the human eye.
Like I said, I don't know if most of you knew this, but I thought it 
interesting....I thought his name derived from "Sirius A", I had no 
idea there was a Sirius B!  

"S Shortsnout"