Tabby's Star

“Tabby’s Star” The most mysterious star in the universe James
R. A. Davenport NSF Astronomy & Astrophysics Postdoctoral Fellow, Western Washington University DIRAC Fellow, University of Washington jradavenport UNIVERSITY OF WASHINGTON

!2 The search for planets around other stars  aka “Exoplanets”

!4 jradavenport

!5 jradavenport ~120 mph

!6 A “Hot Jupiter” jradavenport

!7 Transiting exoplanets jradavenport

!8 jradavenport Transiting exoplanets

!9 Kepler 4 years, 1 ﬁeld Study 200,000 stars Stars
of all ages! jradavenport Transiting exoplanets

!10 jradavenport

!11 First planets announced by Kepler (Jan 2010, DC) jradavenport

!12 An “orrery” jradavenport

!13 jradavenport The Kepler Orrery

Kepler has found some weird & neat things! ? ?
? ? ? ? ? ? ? ? ? jradavenport

jradavenport !16 “Circumbinary planets” jradavenport

!17 jradavenport “Circumbinary planets”

!18 Phase / Longitude Flux jradavenport Kepler can even measure
stars rotating Walkowicz+ (2010)

!19 jradavenport “Tabby’s Star” or “Boyajian’s Star”

!20 “Tabby’s Star” or “Boyajian’s Star”

!21 jradavenport Wikipedia Twitter “Tabby’s Star” or “Boyajian’s Star”

!22 jradavenport

!23 jradavenport

!24 jradavenport “Tabby’s Star” or “Boyajian’s Star”

A seemingly normal “F type” star artist conception

A seemingly normal “F type” star Temperature: 6000–76000 deg K
artist conception

A seemingly normal “F type” star Temperature: 6000–76000 deg K
artist conception ? Huh?

!28 slow 3% fade! The plot thickens “Tabby’s Star” or
“Boyajian’s Star”

!29 1-2% variation jradavenport Continued monitoring… still weird “Tabby’s Star”
or “Boyajian’s Star”

!30 2 Mysterious Behaviors 1.Short timescale: dimming events. Strange shape,
very “deep”, random times.        2.Long Timescale: slow fading. Very slow,   timescale/depth unknown

!31 So, what is it?!    or What isn’t it?

!32 Phase / Longitude Flux Probably not rotation i.e. not
the surface of the star

!33 jradavenport comets?

!34 comets? jradavenport

!35 comets? jradavenport but, 20%…? and?

!36 jradavenport a funky disk or ring? Needs to be
very dynamic, not periodic

!37 jradavenport planet smash?! Needs to be very dynamic, not
periodic

!38 jradavenport Visible light Infrared Far-Infrared Brightness Normal No sign
of a dusty disk

!39 jradavenport

!40 Dyson sphere

!41 Dyson sphere

!42 Visible light Infrared Far-Infrared Brightness Dyson sphere No IR
emission, and no sensible pattern/shape

!43 Well, what DO we know?

!44 Ultraviolet data rules out   “normal” interstellar dust Davenport
et al. (2017)

!45 “Normal” interstellar dust

!47 Long timescale modulations may be repeating…? Simon et al.
(2018)

!48 Long timescale modulations may be repeating…? Simon et al.
(2018) Hippke et al. (2018)

!50 Short timescale modulations may be repeating…?!?!

!51 Current “best idea”…

!52 Current “best idea”…

!53 Current “best idea”… The next frontier: where are the
OTHER “Tabby Stars”?

Tabby's Star

Tabby's Star

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