For some time, trying to draw a circle on the sphere.
It comes to me.
Later this sphere with wheels trying to rotate around its axis.
But the wheels are spinning they are distorted. I want to go to the market in the x, y, z were further round

Please help as this to solve the problem.
Then he also plans to draw an ellipse


Code :
void GLWidget::paintGL()
{
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    // Wyczyszczenie okna bieżącym kolorem tła
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glColor3ub(0,0,34);  // niebieski
    glBegin(GL_QUADS);
        glVertex2f(-20.1f, -20.1f);
        glVertex2f(-20.1f,  20.1f);
        glVertex2f( 20.1f,  20.1f);
        glVertex2f( 20.1f, -20.1f);
    glEnd();
 
    glScaled(this->zoom,this->zoom,1);
 
    // Wyzerowanie macierzy widoku modelu
    glRotatef(-xRot / 16.0f, 1.0f, 0.0f, 0.0f);
    glRotatef(yRot / 16.0f, 0.0f, 1.0f, 0.0f);
    glRotatef(zRot / 16.0f, 0.0f, 0.0f, 1.0f);
 
 
    paintCoordinates();
 
    glRotated(180,0,0,0);
    glColor3ub(255,0,34);  // niebieski
    funkcje f;
    GLfloat kat;
    glBegin(GL_LINE_STRIP);
    daneStarsRA = f.deg2rad(70);
    daneStarsDEC = f.deg2rad(70);
 
    double x = sin(daneStarsRA) * cos(daneStarsDEC);
    double y = -sin(daneStarsDEC);
    double z = sin(daneStarsRA-M_PI/2) * cos(daneStarsDEC);
    double x1,y1;
 
    glBegin(GL_TRIANGLE_FAN);
    for(kat = 0.0f; kat < (2.0f*M_PI); kat += (M_PI/32.0f))
    {
        x1 = (0.1f * cos(kat)) + x;
        y1 = (0.1f * sin(kat)) + y;
        glVertex3d(x1, y1, z);
    }
    glEnd();
 
 
    glBegin(GL_LINE_STRIP);
    daneStarsRA = f.deg2rad(0);
    daneStarsDEC = f.deg2rad(0);
 
    x = sin(daneStarsRA) * cos(daneStarsDEC);
    y = -sin(daneStarsDEC);
    z = sin(daneStarsRA-M_PI/2) * cos(daneStarsDEC);
 
    glBegin(GL_TRIANGLE_FAN);
    for(kat = 0.0f; kat < (2.0f*M_PI); kat += (M_PI/32.0f))
    {
        x1 = (0.1f * cos(kat)) + x;
        y1 = (0.1f * sin(kat)) + y;
        glVertex3d(x1, y1, z);
    }
    glEnd();
 
 
    glBegin(GL_LINE_STRIP);
    daneStarsRA = f.deg2rad(30);
    daneStarsDEC = f.deg2rad(30);
 
    x = sin(daneStarsRA) * cos(daneStarsDEC);
    y = -sin(daneStarsDEC);
    z = sin(daneStarsRA-M_PI/2) * cos(daneStarsDEC);
 
    glBegin(GL_TRIANGLE_FAN);
    for(kat = 0.0f; kat < (2.0f*M_PI); kat += (M_PI/32.0f))
    {
        x1 = (0.1f * cos(kat)) + x;
        y1 = (0.1f * sin(kat)) + y;
        glVertex3d(x1, y1, z);
    }
    glEnd();
 
 
 
    glMatrixMode(GL_MODELVIEW);
    glPopMatrix();
 
    glMatrixMode(GL_PROJECTION);
    glPopMatrix();
 
    glPopAttrib();
}

Regards
Gregory