What are the mantras for Surya Grahan?

The Gayatri Mantra is the most important for a solar eclipse. The Aditya Hridayam from the Ramayana is also particularly appropriate. Other recommended mantras include the Maha Mrityunjaya Mantra for protection, the Rahu Beej Mantra (Om Bhram Bhreem Bhraum Sah Rahave Namah), and the Vishnu Sahasranama. All mantras yield exponentially greater merit during the eclipse period.