How do you catch heatran in heart gold?

You can't catch Heatran in Pokémon HeartGold. Heatran is a Pokémon that was introduced in Generation IV (Pokémon Diamond and Pearl).

Here's a breakdown:

* HeartGold is a Generation IV game, but it is based on the original Gold and Silver games. This means it features the same Pokémon from those games and some new ones, but it doesn't include all the Pokémon from Generation IV.

* Heatran is a Generation IV Pokémon. It was first introduced in Diamond and Pearl and is not available in HeartGold.

If you want to catch Heatran, you'll need to play Pokémon Diamond or Pearl.