system
Given the following post, respond as if you're commenting on Reddit:
human
How much is the gravity of the Sun decreasing because of the mass converted to energy through nuclear fusion?

Is it enough to be measured by changes in the earth's trajectory with our current instruments? Is it negligible because of the low rate at which its happening? Thanks!
gpt
Every second in the Sun's core, 570 million tons of hydrogen are converted to 566 million tons of helium, so the mass loss is 4 million tons per second. This is equivalent to the energy released by the Sun each second in the form of light. (Edit: mostly light; see ignatiusloyola's comment below)

This sounds like a lot, but compared to the mass of the Sun it's negligible. It would take nearly 200 billion years at this rate for the Sun to lose 1% of its mass.

It also loses mass through the solar wind. Currently that mass loss is negligible too, but when it expands into a red giant it will lose a large fraction of its mass that way and Earth's orbit will move outward. Whether it will move out far enough to avoid being swallowed by the Sun is still uncertain.