#astronomy Are There Extra Stars Like Boyajian’s Star?

September 25, 2019 - Comment

Bear in mind KIC 8462852, higher generally known as Boyajian’s star (or you might have seen it known as the “alien megastructure” star)? We nonetheless don’t have a definitive rationalization for this supply’s odd conduct — partially as a result of we thought that Boyajian’s star was one-of-a-kind. However what if it isn’t? Artist’s impression


Bear in mind KIC 8462852, higher generally known as Boyajian’s star (or you might have seen it known as the “alien megastructure” star)? We nonetheless don’t have a definitive rationalization for this supply’s odd conduct — partially as a result of we thought that Boyajian’s star was one-of-a-kind.

However what if it isn’t?

Boyajian's Star (art)

Artist’s impression of a hypothetical ring of mud orbiting KIC 8462852, also referred to as Boyajian’s star. A brand new research has discovered quite a lot of analogs to this mysteriously dipping supply.
NASA / JPL-Caltech

Uncommon Dimming

Comet Swarm

On this artist’s illustration, a star’s mild is blocked by orbiting comets. A swarm of comets is simply one of many many explanations which were proposed for Boyajian’s uncommon light-curve dips.
NASA / JPL-Caltech

Boyajian’s star was first found in 2016 by a gaggle of citizen scientists analyzing mild curves within the Planet Hunters Challenge. This seemingly abnormal supply was doing one thing somewhat extraordinary: its mild curve confirmed a collection of bizarre and irregular dips scattered throughout 1,460 days of remark by Kepler.

Extra dips had been discovered later in ensuing knowledge. The dips final wherever from a number of days to every week, didn’t look like periodic, and block out zero.5–22% of the star’s mild — presenting a mix of traits that appear to rule out most abnormal explanations, corresponding to transiting planets or intrinsic stellar variability. So what causes this weird star’s odd conduct?

The Hunt for Analogs

Up to now, our seek for conclusive solutions stays hindered by a shortage of knowledge. Future observations of Boyajian’s star will proceed to assist us higher perceive its conduct — however that also leaves us working with a pattern measurement of 1 star, which makes it onerous to find out something with certainty.

However what if there are extra stars like Boyajian’s star?

A brand new research revealed by scientist Edward Schmidt (College of Nebraska, Lincoln) particulars the hunt for analogs of this uncommon dipper — with quite a lot of successes!

Extra Dippers Discovered!

Light curves of Boyajian's Star analogs

Gentle curves for the 15 slow-dipper candidates recognized within the research. Click on to enlarge.
Schmidt 2019

Schmidt seemed for Boyajian’s star analogs by making use of an automatic search algorithm to a subset of the Northern Sky Variable Survey dataset, a catalog of sunshine curves for greater than 14 million objects noticed in an enormous photometric survey of variable stars.

The algorithm recognized mild curves that confirmed dipping occasions just like Boyajian’s star. Schmidt then adopted up on promising candidates manually, exploring their mild curves from the All Sky Automated Survey for Supernovae (ASAS-SN) and rejecting sources whose dips may very well be readily defined by issues like a binary companion or intrinsic variability.

In the long run, Schmidt was left with a complete of 21 stars displaying doable uncommon, unexplained dipping.

Additional Observations, Please

The brand new dimming stars fall into two classes:

15 sluggish dippers, whose mild curves present dimming with charges just like Boyajian’s star. These sources might be analogs of Boyajian’s star.

6 speedy dippers, whose mild curves present much more frequent variability. These sources could also be extra excessive variations of Boyajian’s star.
Color-magnitude diagram with dipper stars

An H-R diagram displaying the areas of the 21 candidate dipping stars (circles signify sluggish dippers; triangles signify speedy dippers) discovered on this research. They appear to cluster in two distinct areas of the diagram.
Schmidt et al. 2019

Knowledge from the Gaia Knowledge Launch 2 present that the dipper candidates cluster in two areas on an HR diagram, suggesting that dippers are typically main-sequence stars of ~1 photo voltaic mass or developed purple giants of ~2 photo voltaic lots.

So what’s subsequent? Schmidt encourages different astronomers to comply with up on these candidates and observe their conduct over longer timescales! Maybe one in every of these new dimming stars can reveal what’s occurring with Boyajian’s star — and its analogs.

Quotation
“A Seek for Analogs of KIC 8462852 (Boyajian’s Star): A Proof of Idea and the First Candidates,” Edward G. Schmidt 2019 ApJL 880 L7. doi:10.3847/2041-8213/ab2e77

This submit initially appeared on AAS Nova, which options analysis highlights from the journals of the American Astronomical Society.



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