Binary Star Hypothesis By Henry Norris Russell (1937)

The Binary Star Hypothesis, proposed by American astronomer Henry Norris Russell in 1937, suggests that our solar system formed from a three-star interaction. It’s an example of a “catastrophic” or “encounter” theory, which is no longer widely accepted.

The Binary Star Hypothesis

The theory proposes the following sequence of events:

1. Initial State: The Sun was originally part of a binary star system, meaning it had a companion star orbiting it.
2. The Intruder: A third, “approaching” star passed very close to this system, at a distance estimated to be between 48,000 and 64,000 km from the companion star.
3. Tidal Interaction: The immense gravitational pull of the approaching star exerted powerful tidal forces on the companion star. This is similar to how the Moon creates tides on Earth, but on a stellar scale.
4. Filament Ejection: These tidal forces were strong enough to pull a long filament of gaseous matter from the companion star. According to the hypothesis, the companion star was revolving in a direction opposite to the path of the approaching star, which facilitated the drawing out of this material.
5. Planet Formation: As the approaching star moved away, this filament was left in space. It was then captured by the Sun’s gravity and began to orbit the Sun. Over millions of years, this material cooled, broke into pieces, and condensed to form the planets and other bodies in our solar system.

Criticisms of the Hypothesis

The Binary Star Hypothesis faced significant criticism and has been largely discredited for several key reasons:

• The Companion’s Fate: The theory does not explain what happened to the remaining portion of the companion star after the encounter. It focuses on the filament that formed the planets but fails to account for the massive remnant of the companion star itself. Did it escape the system? Was it destroyed? The model provides no satisfactory answer.
• Contradictory Gravity: A major flaw is the question of gravitational capture. The theory requires the Sun to capture the relatively small, distant filament of matter to form the planets. However, it simultaneously implies that the Sun’s gravity was not strong enough to retain its own, much larger, and closer companion star after the encounter. This scenario is dynamically improbable.
• Low Probability: The chances of such a close stellar encounter are extremely low, making it an unlikely explanation for the formation of the many planetary systems we now know exist.