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 HowellSteve 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 Short Porb, Low M outburst ~ 1/20 yrsoutburst ~ 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. 2013 PASP 125, 1421

Tramposch et al. 2005, PASP 117, 262

Positive SH

Negative SH

SDSSJ2100+00

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 SDSS0926+36

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 J0632+25 from K2-0

Eclipse of accretion column by M star Polar

Schmidt, et al. 2005 ApJ, 620, 422

SDSS1344+20 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. 1998 PASP Pspin= 21 min

Spin from Intermediate Polar

Light curves & DFTs of accreting pulsator SDSS0745+45

SDSS found 9/17 accreting pulsators

Mukadam et al. 2007 ApJ,667

SH

pulse

Mukadam et al. 2013, AJ, 146, 54

Flickering – sec to min

Novalike LS PegNovalike LS Peg

Recurrent nova Recurrent nova (Dobratka et al. 2010)(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

2000-2008

Szkody et al. AJ

2002-2011

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 What future surveys need to enable good science for CVs and other variables: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