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

Disk AM CVns

High state (high Ṁ)

• Hot ionized disk

~20

~10

~40-60 (?)

Low state (low Ṁ)

• Cold stable disk

Caltech

Caltech

• P_orb 20 to ~ 60 minutes (?)

• Superoutburts (SO) and "Normal" outbursts (NO)

• Disk instability model (DIM)

  •  Constant Mass transfer rate

  • Tidal-thermal disk instability model

    • SO: Superhumps (periodic brightness variation )

Outbursting Systems

Tidal radius

3:1 Resonance radius

Accretion disk

Precessing eccentric disc

Kley et al. 2008

Kimura 2020

Caltech

• P_orb 20 to ~ 60 minutes (?)

• Superoutburts (SO) and "Normal" outbursts (NO)

• Disk instability model (DIM)

  •  Constant Mass transfer rate

  • Tidal-thermal disk instability model

    • SO: Superhumps (periodic brightness variation )

Outbursting Systems

Better LC → Better Constraints

Place Constraints

Tidal radius

3:1 Resonance radius

Accretion disk

1. T_rec ∝ P_orb^7.35
2. T_dur ∝ P_orb^4.45
3. Δ mag ∝ Porb
4. Ground-Based:
   1. PTF/CRTS
   2. LINEAR
   3. ZTF

Levitan et al. 2015

See also Duffy et al. 2021

Better LC → Better Constraints

Constraint Empirical Relationships

Outbursts

Pichardo Marcano et al. (2021)

SO duration

ASASSN-14cc

Pichardo Marcano et al. (2021)

9–18 d

kato et al. (2015)

• 2 Super Outbursts:
  • P_orb 22.5 min
  • Variable in length
    • Compare Kato+'15 and Duffy+'21
• Superhump period
  • 10 minute cadence

~7 d

• Precursor
  • TESS (Duffy et al. 2021)
• 5/6 have Precursor
  • Except ASASSN-14cc

PTF1 J0719+4858

Pichardo Marcano et al. (2021)

ZTF

TESS

Precursor

Type of Super Outbursts

Osaki et al. (2005)

High Mass Ratio

DIM

Cataclysmic Variables

See also Duffy et al. (2021)

High Mass Ratio

High Mass Ratio

High Mass Ratio

 eccentric disc develops rapidly

Type of Echo Outbursts

SDSS J1043+5632

• P_orb = 28.5 min
• WZ Sge like
  • Precursors
  • EMT (Hameury+'20)
  • Reflection:
    • Hot Massive WD

• P_orb = 26.7 min
• Compare to TCP J21040470+4631129
  • EMT (Hameury+'20)
• Helium "SU UMa"
  • EMT+TTI (Kotko+'12)

SO

rebrightening

SO

rebrightening

• Color Evolution

PTF1 J0719+4858

Pichardo Marcano et al. (2021)

ZTF

SO

NO

SO

NO

rebrightening

rebrightening

Color Evolution

PTF1 J0719+4858

SS Cyg

Cataclysmic Variable

• Similar to Dwarf Novae

  • Hameury et al. (2020)

• Similar SDSS J1411+4812
  • Rivera Sandoval et al. (2021)
• Compare to SDSS 1137
  • Rivera Sandoval et al. (2021)

Pichardo Marcano et al. (2021)

Color Evolution

PTF1 J0719+4858

• Similar to Dwarf Novae

  • Hameury et al. (2020)

• Similar SDSS J1411+4812
  • Rivera Sandoval et al. (2021)
• Compare to SDSS 1137
  • Rivera Sandoval et al. (2021)

Pichardo Marcano et al. (2021)

SDSS J113732+405458

 Enhanced mass transfer

Rivera Sandoval et al. (2021)

P_orb = 26.7 min

P_orb ~ 60 min

• Color Evolution

SDSS J1043+5632

Pichardo Marcano et al. (2021)

ZTF

TESS

SDSSJ1043+5632

• Similar to Dwarf Novae:
  • Hameury et al. (2020)
  • Rivera Sandoval et al. (2021)

Color Evolution

Long-term monitoring

• Observed 357 days
• Recurrence Time:
  • 203 days
• P_orb = 30.14 min :
  • 2-minute cadence
• "Normal Outburts"

Sector 5

Sector 12

Normal Outbursts

V803 Cen

• V803 Cen
  • P_orb = 26.9 min
  • "Cycle"
  • Low Ṁ
• PTF1 J2219+3135:
  • New P_orb= 27.7 min
  • Agrees with T_rec
  • Permanent Superhumper?

Superoutburst duration vs P_orb

Pichardo Marcano et al. (2021)

TACOS Summary

• Precursors and "Normal" Outbursts:
  • Relatively Common
  • Short Duration (missed by ground-based)
• Echo Outbursts:
  • Different morphology
  • Enhanced Mass Transfer
• Superoutburst durations overestimated
• Two new candidate orbital periods
  • Constraint on T_rec vs. P_orb
• Color Evolution

Extra

Mass-transfer rates vs orbital period

Mass-transfer rates vs orbital period

Other work with Accreting WDs

• Follow-up eROSITA transient:

• TESS time series analysis

• • Atel: Pichardo Marcano (2020)

  • Paper: Schwope, [...], Pichardo Marcano, et al. (2021)

Caltech

PTF1 J0719+4858:

• Similar to Dwarf Novae:
  • Hameury et al. (2020)
  • Rivera Sandoval et al. (2021)

Color Evolution

Pichardo Marcano et al. (2021)

Normal Outbursts

V803 Cen

• WZ Sge like ?
  • Precursors
  • EMT (Hameury+'20)
  • Massive WD?

• Compare to TCP J21040470+4631129
  • EMT (Hameury+'20)
• Helium "SU UMa"
  • EMT+TTI (Kotko+'12)

Long-term monitoring

Pichardo Marcano et al. (2021)

• Orbital Periods:
  • 2-minute cadence
• Limits on Recurrence Time
• "Normal Outburts"