Find all the integer pairs $ (x,y)$ such that:
                                  \[ x^2\minus{}y^4\equal{}2009\]
To find all integer pairs \((x, y)\) such that \(x^2 - y^4 = 2009\), we can proceed as follows:

1. **Factorization and Parity Consideration**:
   - Notice that \(2009 = 7^2 \cdot 41\).
   - Since \(x^2 - y^4 = 2009\), \(x\) and \(y\) must be of different parity (one even, one odd) because \(2009\) is odd.

2. **Greatest Common Divisor (GCD) Analysis**:
   - Let \(\gcd(x, y) = g\). Then we can write \(x = gm\) and \(y = gn\) where \(\gcd(m, n) = 1\).
   - Substituting these into the equation, we get:
     \[
     (gm)^2 - (gn)^4 = 2009 \implies g^2(m^2 - g^2n^4) = 2009
     \]
   - Since \(2009 = 7^2 \cdot 41\), \(g\) must be a divisor of \(7\). Therefore, \(g = 1\) or \(g = 7\).

3. **Case \(g = 1\)**:
   - If \(g = 1\), then \(x = m\) and \(y = n\), and the equation simplifies to:
     \[
     x^2 - y^4 = 2009
     \]
   - We can factorize the left-hand side:
     \[
     (x - y^2)(x + y^2) = 2009
     \]
   - Since \(\gcd(x - y^2, x + y^2) = \gcd(x - y^2, 2y^2) = 1\) (because \(x\) and \(y\) are of different parity), the factors of \(2009\) must be \(1\) and \(2009\), or \(7\) and \(287\), or \(41\) and \(49\).

4. **Possible Factor Pairs**:
   - Consider the factor pairs \((x - y^2, x + y^2)\):
     - \( (1, 2009) \) does not work because it does not yield integer solutions.
     - \( (7, 287) \) does not work because it does not yield integer solutions.
     - \( (41, 49) \):
       \[
       x - y^2 = 41 \quad \text{and} \quad x + y^2 = 49
       \]
       Adding these equations:
       \[
       2x = 90 \implies x = 45
       \]
       Subtracting these equations:
       \[
       2y^2 = 8 \implies y^2 = 4 \implies y = \pm 2
       \]
     - Therefore, the solutions are \((x, y) = (45, 2)\) and \((x, y) = (45, -2)\).

5. **Case \(g = 7\)**:
   - If \(g = 7\), then \(x = 7m\) and \(y = 7n\), and the equation becomes:
     \[
     (7m)^2 - (7n)^4 = 2009 \implies 49m^2 - 2401n^4 = 2009 \implies 49(m^2 - 49n^4) = 2009 \implies m^2 - 49n^4 = 41
     \]
   - This implies:
     \[
     (m - 7n^2)(m + 7n^2) = 41
     \]
   - The factor pairs of \(41\) are \((1, 41)\) and \((-1, -41)\):
     - For \((1, 41)\):
       \[
       m - 7n^2 = 1 \quad \text{and} \quad m + 7n^2 = 41
       \]
       Adding these equations:
       \[
       2m = 42 \implies m = 21
       \]
       Subtracting these equations:
       \[
       14n^2 = 40 \implies n^2 = \frac{40}{14} = \frac{20}{7} \quad \text{(not an integer)}
       \]
     - Therefore, there are no integer solutions for \(g = 7\).

Conclusion:
The only integer solutions are \((x, y) = (45, 2)\) and \((x, y) = (45, -2)\).

The final answer is \(\boxed{(\pm 45, \pm 2)}\).