Is Power Artifact legal in Standard, Modern, and Commander?

Power Artifact is legal in: Legacy, Vintage, Commander.

What type of card is Power Artifact?

Power Artifact is an Enchantment — Aura. Its oracle text reads: "Enchant artifactEnchanted artifact's activated abilities cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana."

Power Artifact

Enchantment — Aura

Enchant artifact<br>Enchanted artifact's activated abilities cost less to activate. This effect can't reduce the mana in that cost to less than one mana.