Sirius

White Dwarf

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

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

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

Astronomical Surveys

Astronomical Surveys

Unsupervised Time Series Classification

Extract Time Series Features

Cluster Time Series

Unsupervised Time Series Classification

Time-series everywhere

Unsupervised Time-Series Classification

Searching for Exotic Binaries using their light-curves?

Unsupervised Time-Series Classification

Searching for Exotic Binaries using their light-curves?

JD - 2458636

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

Unsupervised "Time-Series" Classification

Gaia Spectra

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

Gaia Spectra

Apply new methods?

• Wavelets?
  • Gaussian Process + PCA

Information bottleneck method?  

Based on mutual information. 1 hyper-parameter.

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

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

AM Canum Venaticorum AM CVn

• White dwarf + White dwarf

• White dwarf + He Star

• Orbital Period: 5-70 minutes

• Rare: 70 Galactic field