Should we keep Navagraha idols in the home mandir?

most families do not keep Navagraha idols at home and worship them in temples or through stotras; if your family has a yantra or custom, continue it.

The nine grahas — Sūrya, Candra, Maṅgala, Budha, Guru, Śukra, Śani, Rāhu and Ketu — are honoured as divine beings who carry out the results of karma. In most temples they stand on a separate platform, each facing a different direction, and devotees walk around them, often nine times.

In the home mandir, the general custom is to keep the main deities and not separate Navagraha idols; the grahas are honoured instead through the daily Sūrya arghya, the Navagraha Stotra attributed to Vyāsa (“Japākusuma-saṅkāśaṁ…”), and a Navagraha pūjā or śānti when an astrologer advises it, for example in a griha-praveśa. Some families keep a Navagraha yantra installed by a priest, and that is fine to continue with regular worship.

Worship of your main deity — Śiva, Viṣṇu, Devī or Hanumān — is also traditionally said to bring the grahas’ blessings with it.

Source: Navagraha Stotra (attributed to Vyāsa); temple practice · Nine grahas, including Rāhu and Ketu

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