Urbain Le Verrier Announces Vulcan at the French Academy, 1860

On January 2 1860 the French mathematician Urbain Le Verrier announced at the French Academy of Sciences that he had found evidence for a new planet he called Vulcan. The claim aimed to explain oddities in Mercury’s orbit and sparked widespread interest in a planet between the Sun and Mercury.

Le Verrier’s reputation and the search for new planets

Urbain Jean Joseph Le Verrier was a French astronomer and mathematician known for predicting Neptune’s position using only mathematics. His success gave him credibility in celestial mechanics, encouraging him to address other orbital puzzles.

The Vulcan hypothesis

Vulcan was a hypothetical planet proposed to exist in an orbit between Mercury and the Sun. Astronomers had speculated about such an intermercurial body since the early 17th century, hoping it would account for irregularities in Mercury’s motion.

Why the announcement mattered

Presenting the claim at the French Academy of Sciences—a learned society founded in 1666 to promote French scientific research—gave the idea high visibility. The proposal influenced 19th‑century discussions of planetary motion and highlighted the limits of existing astronomical theory.

Key facts

• Date of announcement: January 2 1860.
• Speaker: French mathematician and astronomer Urbain Le Verrier.
• Venue: Meeting of the French Academy of Sciences in Paris.
• Vulcan was imagined as a planet between the Sun and Mercury.

Frequently asked questions

Who announced the discovery of Vulcan?

Urbain Le Verrier, a French astronomer and mathematician, announced it.

Where was the announcement made?

At a meeting of the French Academy of Sciences in Paris.

What was the purpose of proposing Vulcan?

To explain observed irregularities in Mercury’s orbit by positing a planet between Mercury and the Sun.