What Is Dimming KIC 8462852? Alien Megastructure Star Update 10/06/2016

TL;DR

The cause of KIC 8462852’s dimming remains unknown, although natural explanations such as passing debris or disintegrating comets are more likely than an alien megastructure. Observations indicate two puzzles: deep short-term dips and a possible long-term dimming trend spanning a century. Kepler data strengthens the case for the longer trend, while the lack of infrared emissions constrains several theories. Read on to compare how each explanation fits the evidence.

Transcript

This is another installment in my continuing coverage of KIC 8462852 or Tabby's star, easily the strangest star we've yet come across in our universe. Since my last update, a number of scientific papers have been published that offer a new group of potential explanations for the dimming phenomena, but the possibility of alien megastructures causing... Read More

Key Insights

• 🍉 There are two phenomena at Tabby's star: major short-term dimming events and a long-term dimming trend over a century.
• 👶 The long-term dimming trend was initially disputed but seems to be confirmed by new data from Kepler.
• 👶 New theories suggest natural explanations such as a debris disk or disintegrating comets for the dimming events.
• 👽 The possibility of alien megastructures causing the dimming events is still on the table, but highly unlikely.
• 🤩 More observations of Tabby's star are needed to provide further insights into the cause of the dimming events.
• 😶‍🌫️ The lack of infrared emissions supports the theory of a cold cloud or disc of debris causing the dimming.
• 👷 The rapid construction implied by the megastructure theory contradicts the findings of the long-term dimming trend.

Questions & Answers

Q: What is causing the dimming of KIC 8462852?

The cause remains unknown. Proposed natural explanations include a passing cloud or disk of debris, disintegrating comets, and debris associated with a younger star, while an alien megastructure remains possible but highly unlikely.

Q: What two dimming phenomena have been observed at Tabby’s Star?

The first consists of the deep, short-term dimming events that initially drew attention to the star. The second is a possible long-term dimming trend occurring over the course of a century.

Q: Does KIC 8462852 really have a long-term dimming trend?

The existence of the trend was disputed after Michael Hippke questioned Bradley Schaeffer’s methodology and reported no supporting evidence from another plate collection. Later analysis by Benjamin Montet using Kepler data tipped the evidence in favor of a long-term trend, although the star still requires further observation.

Q: How could passing debris explain Tabby’s Star’s dimming?

A cloud or disk of debris could pass across the line of sight to Tabby’s Star without being directly associated with it. Different densities within that material could produce deep dips and a dimming trend lasting centuries.

Q: Why is the lack of infrared emissions important?

Material orbiting KIC 8462852 might be expected to produce detectable infrared emissions. A cold cloud or disk in interstellar space could account for the lack of those emissions, making passing debris a potentially better fit.

Q: Could disintegrating comets explain the dimming events?

A very large number of disintegrating comets could reproduce the short-term dimming events seen in the Kepler data. However, the comet models could not explain every observation, so the theory does not fully resolve the mystery.

Q: Why is the alien megastructure explanation considered unlikely?

The Kepler light curves may be consistent with a large space-based baffle, but the long-term dimming would imply extremely rapid construction. The speaker argues that this speed works against the megastructure explanation, which remains the least likely proposal discussed.

Q: How can scientists determine whether the dips repeat periodically?

Scientists must continue observing KIC 8462852 and check for recurring periodic dips. Active observations are already underway, but the transcript notes that obtaining a clear answer could take several years.

Summary & Key Takeaways

• Scientists have discovered two phenomena at Tabby's star: major short-term dimming events and a long-term dimming trend over a century.

• The long-term dimming trend was initially questioned, but new data from Kepler seems to confirm its existence.

• Several theories have emerged to explain the short-term dips, including a debris disk passing in front of the star or a cloud of disintegrating comets.