Cataclysmic Variables: A Perfect Testbed for Variability Brokering Paula Szkody University of Washington Santa Barbara May 13, 2015

Disk System Polar Intermediate Polar LARP CV Types Steve Howell

Summary of Variability and timescales for Interacting Binaries

Dwarf nova outbursts Novalikes - high-low states 1 week to 30 years

K2-0

K2-1 TW Vir

 parabola-like decay of outburst  linear and slow transit between outburst and quiescence.  quiescence covering at least 28 days shows typical flickering behavior. ~ 1 mag ~ 4.5 days 28 days USNO Dwarf nova K2-0

July 23 Short Porb, Low M outburst ~ 1/20 yrs.

V1159 Ori ER UMA Type Supercycles Szkody et al. 1999, ApJ, 521, 362

Z Cam system standstills quiescence outburst Szkody et al PASP 125, 1421

Tramposch et al. 2005, PASP 117, 262 Positive SH Negative SH SDSSJ P=2.099 hr P=1.96 hr

Novalike systems (VY Scl, SW Sex types) Honeycutt & Kafka, 2004, AJ, 128, 1279 Low states

Honeycutt, Turner & Adams 2003 Roboscope 10 yr erratic variability

Orbital variability - hrs

P=3.96hr Eclipsing systems- WD goes behind M star P=2.4hr Hot spot Szkody et al. 2003,2004, AJ

Phot P: 42.5 min Spect P: 85 min Long P: hrs Szkody et al. 2006, AJ 131, 973

Eclipsing AM CVn P=28 min, eclipse=1 min

CRTS data on SDSS

3.9 hr Orbital: 7.8 hr  VSNET reported in 2012 that its periodicity may not be stable. But, the two significant peaks shown in our periodogram confirm the previously derived period and its harmonic. SDSS J from K2-0

Eclipse of accretion column by M star Polar Schmidt, et al ApJ, 620, 422

SDSS KPNO 2.1m 2011 Day-week variability of a Polar Szkody et al. 2014, AJ 148, 63

PTF candidate magnetics (Margon, Levitan,Prince, Hallinan 2013 ASPCS)

Examples from CSS

White dwarf spin, pulsations - minutes

FO Aqr Patterson et al PASP P spin = 21 min Spin from Intermediate Polar

Light curves & DFTs of accreting pulsator SDSS SDSS found 9/17 accreting pulsators Mukadam et al ApJ,667

SH pulse Mukadam et al. 2013, AJ, 146, 54

Flickering – sec to min

Novalike LS Peg Recurrent nova (Dobratka et al. 2010) Flickering Examples

Effects of Color

Cyclotron harmonics result in strange colors

Low Accretion Rate Polars as a function of magnetic field Schmidt et al. 2005, ApJ, 630, 1037

P=4.4 hrs Cyclotron harmonics depend on filter and orbital phase Szkody et al. 2008, ApJ 683, 967

CVs in SDSS Szkody et al. AJ Papers I-VIII Need lots of follow-up spectra for ID and properties! What we learned from SDSS: Cyclotron humps Pulsating WD

Howell, Nelson, Rappaport 2001, ApJ, 550 Log number of CVs Population models PG, Hamburg SDSS. ID+period constrains evolution LSST

Survey Results depend on: Limiting magnitude Filter(s) or spectra Cadence Timespan covered

What future surveys need to enable good science for CVs and other variables: a cadence that produces a recognizable light curve sufficient colors to aid in classification rapid/smart classification to ensure followup as needed spectral followup to confirm classification and provide basic parameters