Decipher the greeting card $( X^2 +Y^2 -1 ) ^3 - X^2 Y^3 = 0$

Question

A friend of mine just got a rather weird congratulations card through the door

They have zero idea what it means, I have tried graphing it and nothing spectacular comes out. Is there a standard name for this equation or does it signify anything?

Any help would be appreciated.

Answer 1

Using Maple it is:

 [> with(plots):
    implicitplot((x^2+y^2-1)^3-x^2*y^3 = 0, x = -10 .. 10, y = -10 .. 10);

Answer 2

http://mathworld.wolfram.com/HeartCurve.html

Have a look at the second graph here

It is a cardiod curve.

Answer 3

Your friend had a great equation for his greetings, check the graph below