Sirius from Nashville

Sirius A

"Normal Star"

Sirius B

White Dwarf

Closest White Dwarf

 Mroz et. al (2016) Image: (J. Skowron, K. Ulaczyk / Warsaw University Observatory)

Variability Search

Vera C. Rubin Observatory

• 20 TB per day
• ~40 billion catalog objects
• Observe the entire southern night sky every three nights.

Transiting Exoplanet Survey Satellite TESS

Astronomical Surveys

Unsupervised Time Series Classification

Extract Time Series Features

Cluster Time Series

Time-series everywhere

Unsupervised Time-Series Classification

Searching for Exotic Binaries using their light-curves?

• Feature Selection:
  • Mean, Max, Min, ...
• Clustering Methods:
  • Affinity Propagation algorithm
  • K-means
• Distance Metric:
  • Time Warp Edit Distance
  • Dynamic Time Warping

Extra

NASA

Stellar Remants

White Dwarfs

Mass ~ 1 M☉

Radius ~ 1 R🜨

Radius ~ 1 R🜨

TESS Cadence and Coverage

• Primary mission:
  • 2-min selected targets
  • 30-min full-frame images (FFI).
• Extended:
  • 20 sec selected targets
  • 10-min FFI
• Second extended mission
  • 200-second FFI

A Binary White Dwarf

Accreting White Dwarf Binaries

Caltech

Semi-detached systems

Cataclysmic Variables

AM CVn

• "Normal" Star
• P_orb ~ 80 min - 10 hours
• >1000 in the galactic field
• Predicted large # in old Star Clusters

• White Dwarf/Helium Star
• P_orb ~ 5 - 70 min
• Poorly understood Outburst
• Type Ia SN and GW Sources
• ~70 in the galactic field

Caltech

Mark A. Garlick

Hydrogen-rich  "normal" Star

White Dwarf

White Dwarf

White Dwarf

Gaia:

Mapping the Milky Way

Gaia:

Mapping the Milky Way

Big Data in Astronomy

Astrophysics and Big Data: Challenges, Methods, and Tools. DOI: 10.1017/S1743921316012813

Unsupervised Time-Series Classification

Unsupervised Time-Series Classification

Unsupervised Time-Series Classification

> 1200 Time-Series Features

Unsupervised Time-Series Classification

Searching for Exotic Binaries using their light-curves?

JD - 2458636

AM Canum Venaticorum AM CVn

• White dwarf + White dwarf

• White dwarf + He Star

• Orbital Period: 5-70 minutes

• Rare: 70 Galactic field