Manuel Pichardo Marcano (Fisk/Vanderbilt)

 

A Needle in a Haystack:

Finding Exotic Binaries in Astronomical Surveys

 

White Dwarfs

Mass ~ 1 M☉

Radius ~ 1 R🜨

Radius ~ 1 R🜨

NASA

Stellar Remants

Sirius

White Dwarf

Sirius A

"Normal Star"

Sirius B

White Dwarf

Closest White Dwarf

A Binary White Dwarf

Accreting White Dwarf Binaries

Caltech

Semi-detached systems

Cataclysmic Variables

AM CVn

  • "Normal" Star
  • Porb ~ 80 min - 10 hours
  • >1000 in the galactic field
  • Predicted large # in old Star Clusters
  • White Dwarf/Helium Star
  • Porb ~ 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

AM Canum Venaticorum AM CVn

  • White dwarf + White dwarf

  • White dwarf + He Star

  • Orbital Period: 5-70 minutes

  • Rare: 70 Galactic field

Caltech

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

Variability Search

Astronomical Surveys

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

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

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

Extract Time Series Features

Cluster Time Series

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

Szkody et. al (2020)

Magnitude

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