From the source
OpenAI announced GPT-6 Sol and GPT-6 Luna, two new models in the GPT-6 family that are faster and more affordable than GPT-6 Astra.
Sol ($2 input, $10 output per million tokens) and Luna ($0.10 input, $0.50 output) aim to reduce costs for professional work, coding, and agentic tasks.
The models are rolling out in ChatGPT Work and Codex for Plus, Pro, Business, Enterprise and Edu users; Luna is also available to Free and Go users in the desktop app.