Manuel Pichardo Marcano (he/him)

Manuel Pichardo Marcano

  • De Santo Domingo, Rep. Dom.
  • 1 año en la UASD
  • B.S. Utah State University
  • M.S. Université Toulouse III-Paul Sabatier
  • PhD Texas Tech University
  • 1 año Post-doc AMNH
  • Sept EMIT Post-doc enVanderbilt/Fisk

Text

Estudio Binarias Compactas

Caltech

NASA

Credits: NASA/Rivera Sandoval

Cúmulos Globulares

47 Tuc en Rayos X

47 Tuc en Óptico

Estudio Binarias Compactas

2- SCOVaS: Survey for Compact Objects and Variables

 

Pichardo Marcano et al. (2021a)

Pichardo Marcano et al. (2023)

   Pichardo Marcano et al. (in prep.)

 

1- TACOS: TESS AM CVn Outbursts Survey

Pichardo Marcano et al. (2021b)

Caltech

NASA

¿Qué es una Estrella?

  • Objeto celeste autogravitatorio:
    • unido por la atracción gravitacional de sus partes.
  • Hay, o hubo una vez fusión termonuclear sostenida de hidrógeno en su núcleo.

Estrellas

El Sol

Enana Blanca Y

Estrella de Neutrones

No Estrellas

No Todas son Iguales

Diferencias:

  • Brillo Aparente:
    • Brillo ∝ 1/distancia2
    • Distancia:
      • Luminosidad (Brillo intrínseco) [Vatios]
      • L ∝ R2 T4
    • Color
      • Temperatura
    • Masa y Radio
      • Difíciles de Medir

25 Estrellas Más Brillantes

El Sol como una estrella

Nuestro Referente Estelar

Luminosidad Solar = 1 L☉ = 3.8 x 1026 Vatios

Masa Solar = 1 M☉ = 1.988 x 1030 Kg

Radio Solar = 1 R☉ = 695700 km

Temperatura ∼ 5772 K = 5498.85 C

 

Medir la temperatura del Sol

Todo lo que tiene temperatura > 0 K emite radiación (luz)

Medir la temperatura del Sol

Todo lo que tiene temperatura > 0 K emite radiación (luz)

Radiación de cuerpo negro

Medir la temperatura del Sol

El Color Depende de la Temperatura

Radiación de cuerpo negro

Necesitamos la Distancia

¿Cómo medir la Luminosidad?

Brillo ∝ L/distancia 2

Luminosidad ∝ Brillo X distancia 2

1 L☉

Gaia

El Cartógrafo de la Vía Láctea

  •  Telescopio espacial de la Agencia Espacial Europea (ESA)
  • ∼ 2 mil millones de estrellas
    • Distancias, Colores, Brillos Aparentes, Movimientos Propios

El paralaje

Gaia

¿Cómo Gaia mide distancias?

Gaia

¿Cómo Gaia mide distancias?

El paralaje

Gaia

¿Cómo Gaia mide Colores (temperatura)?

Filtros

  • Gaia tiene 3 Filtros:
    • G, BP (Azul), RP (Rojo)

Longitud de Onda

El Diagrama H-R de Gaia

Luminosidad

                          Temperatura                            

Color                     

Azul <-

Rojo ->

Más Luminosas

Menos Luminosas

 <- Más Calientes

 Menos Calientes ->

El Diagrama H-R de Gaia

Luminosidad (L)

                          Temperatura                            

Color                     

Azul <-

Rojo ->

Más Luminosas

Menos Luminosas

 <- Más Calientes

 Menos Calientes ->

Secuencia Principal

Enanas Blancas

Gigantes

La Secuencia Principal

                          Temperatura                            

Luminosidad (L)

Estrellas Masivas

.

Estrellas de Baja Masa

1 M☉

50 M☉

0.5 M☉

La Secuencia Principal

Estrellas "Normales"

  • Sostenidas por Fusión Nuclear:
    • H-> He
  • Pasan la mayor parte de su vida
    • L ∝ M4
    • Estrellas Masivas Viven Menos

La Secuencia Principal

Luminosidad

Color                     

Azul <-

Rojo ->

Secuencia Principal

¿Qué son estas letras?

Clasificación de Las Estrellas

Las Estrellas se clasifican de acuerdo a sus Espectros

Se pasa la luz por un "prisma"

El Espectro del Sol

La Huella Digital de las Estrellas

Las "Computadoras" de Harvard

Annie Jump Cannon:

Desarrolló el sistema de clasificación basado en Temperatura

O B A F G K M

 

Clasificación de las estrellas

El Sol (G)

   Temperatura                            

Clasificación de las estrellas

   Temperatura                            

Clasificación de las estrellas

   Temperatura                            

¿Por que los espectros se ven diferentes?

Cecilia Payne-Gaposchkin:

  • La mujer que descubrió la composición de las estrellas.
  • Primera interpretación teórica de los espectros.

I- Secuencia Principal ( 10 mil millones de años)

  • Fusionando H en He

El Ciclo de Vida del Sol

¿Qué pasa cuando se le acaba el Hidrógeno?

El Sol y la mayoría de las estrellas del universo terminaran como una enana blanca

II- Gigante Roja

  • Núcleo inerte de Helio
  • Capas exteriores extendidas
  • Fusión de H a He en las capas

 

 

El Ciclo de Vida del Sol

II- Gigante Roja

El Ciclo de Vida del Sol

Nucleo Inerte

de He

Capa Fusionando H->He

Capa Exterior

Extendida

II- Gigante Roja

El Ciclo de Vida del Sol

                          Temperatura                            

Luminosidad (L)

Secuencia Principal

Tope Rama Gigante Roja

Base Rama Gigante Roja

Subgigante

II- Gigante Roja

El Ciclo de Vida del Sol

III- Flash de Helio

El Ciclo de Vida del Sol

                          Temperatura                            

Luminosidad (L)

Secuencia Principal

Rama Gigante Roja

Flash de Helio

Rama Horizontal​

IV- Rama Horizontal

El Ciclo de Vida del Sol

Núcleo Fusionando

He

Capa Fusionando H->He

Capa Exterior

Extendida

  • Helio se convierte en Carbono

V- Rama Asintótica Gigante

El Ciclo de Vida del Sol

Nucleo Inerte

de C

Capa Fusionando H->He

Capa Fusionando He

Capa Exterior

Extendida

V- Rama Asintótica Gigante

El Ciclo de Vida del Sol

                          Temperatura                            

Luminosidad (L)

Secuencia Principal

Rama Asintótica Gigante

V- Rama Asintótica Gigante

El Ciclo de Vida del Sol

Origen de los elementos

VI- Nebulosa Planetaria

El Ciclo de Vida del Sol

                          Temperatura                            

Luminosidad (L)

Secuencia Principal

Nebulosa Planetaria

VI- Nebulosa Planetaria

El Ciclo de Vida del Sol

Enana Blanca

Enanas Blancas

Masa ~ 1 M☉

Radio ~ 1 R🜨

 

Radio ~ 1 R🜨

Estrellas "Muertas"

Masa ~ 1 M☉

Radio ~ 1 R🜨

 

Radio ~ 1 R🜨

Presión Electrones

Fusión Nuclear

El Ciclo de Vida del Sol

Luminosidad (L)

            Temperatura             

Enana Blanca

Nebulosa Planetaria

RH

El Ciclo de Vida de Millones

Luminosidad

RGB = Rama de Gigante Roja

HB = Rama Horizontal

AGB = Rama Asintótica Gigante

Color                     

Azul <-

Rojo ->

Resumen

 

Cosas de las que no hablé

  • Evolución Estrellas Masivas:
    • Supernovas
    • Hoyos Negros
    • Estrellas de Neutrones
  • Evolución Estrellas Mediana Masa:
    • Enanas Blancas Masivas
    • Supergigante Rojas
  • Evolución Binaria
    • Formación de binarias compactas
    • Fuentes de ondas gravitacionales

Supergigante

Gigante

Cosas de las que sí hablé

  • Gaia
    • Cartógrafo de la Vía Lactea
  • El Diagrama H-R:
    • Diagrama más importante/útil para la astronomía estelar
  • Clasificación de Estrellas:
    • Espectros
  • Ciclo de Vida del Sol:
    • Estrellas de baja masa
    • Estrellas más comunes

Manuel Pichardo Marcano

Email: manuelpichardom@gmail.com

Extra

Accreting White Dwarf Binaries

Cataclysmic Variables

AM CVn

  • Main Sequence Star
  • Porb ~ 80 min - 10 hours
  • Outbursts:
    • 2-20 days
    • Disk instability model+ (DIM)
  • >1000 in the galactic field
  • Predicted large # in old Star Clusters
  • White Dwarf/Helium Star
  • Porb ~ 5 - 70 min
  • Outburts:
    • weeks?
    • DIM?
  • ~70 in the galactic field

Mark A. Garlick

Caltech

AM Canum Venaticorum AM CVn

  • White dwarf + White dwarf

  • White dwarf + He Star

  • Orbital Period: 5-70 minutes

  • Rare: 70 Galactic field

Caltech

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

Luminosity

Period (min)

High state (high Ṁ)

  • Hot ionized disk

Outbursting System

~20

~10

~40-60 (?)

Low state (low Ṁ)

  • Cold stable disk

Caltech

Outbursts

Pichardo Marcano et al. (2021)

SO duration

  • 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

PTF1 J0719+4858

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

  • 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)

rebrightening

SDSS J113732+405458

 Enhanced mass transfer

Rivera Sandoval et al. (2021)

Porb = 26.7 min

Porb ~ 60 min

Superoutburst duration vs Porb

Pichardo Marcano et al. (2021)

Cataclysmic Variables

  • White dwarf primary

  • "Main-sequence" donor

  • Roche-lobe overflow

  • Accretion disk (non-magnetic)

  • Highly Variables:

    • Dwarf novae

      • 2-8 mag outburst

      • 10-100 increase in L

Looking of CVs in GCs

NASA, ESA, H. Richer and J. Heyl (University of British Columbia), and J. Anderson and J. Kalirai (STScI)

Binaries in Globular Clusters

  • Globular Clusters
    • The binary population drives the dynamical evolution of GCs
  • Cataclysmic Variables:
    • Large (predicted) sample at known distance
    • Potentially very different from field CVs
    • A lot of open questions
  • Gravitational Waves:.
    • White dwarf degenerate sources for LISA

Finding CVs in X-rays and UV

  • Advantages of X-ray Searches:

    • Avoid crowding
  • Disadvantages:

    • Small FoV (FUV)
    • Lx ≥ 1029 ergs/s

Significant X-ray bias

X-ray: NASA/CXC/CfA/J.Grindlay & C.Heinke; Optical: ESO/Danish 1.54-m/W.Keel et al.

Summary CVs in GCs

  • Few of CVs per cluster

  • X-ray biased sample:

    • Lx > 1029ergs/s

  • Dearth of DNe:

    • Only 17 confirmed

  • Core-collapsed:

    • Bimodal population

  • Non core-collapsed:

    • 1 faint population

  • Period distribution?

    • 16 known periods

Need more detections. Need more Periods

All Magnetics ?

  • HST Archive
  • 7 Globular Clusters
  • Many Exposures
  • Different properties
    • Metallicity
    • Core-collapsed
    • Non core-collapsed

SCOVaS: Survey for Compact Objects and Variables

  

Preliminary Results

NGC 6397

  • Closest Core Collapse
  • Second Closest
    • 2.4 kpc
    • 15 CV candidates
    • 2 Pulsars

Preliminary Results

NGC 6397

Where are all the CVs?

We haven't found new

X-ray faint CVs

Spoiler Alert!

Other Binaries

Credits: NASA/Rivera Sandoval

Main et al 2018 (Nature)

Redback 'spider' Pulsar

Redback  Pulsar

A new candidate Redback MSP

Pichardo Marcano et. al (2021a)

  • Porb 1.96 days
  • Longest Porb for Redback in GCs
  • Missed MSP in Pulsar Searchers
    • Confirmed by Zhang et al. (2022)

Magnetic He WD Candidate

  • Vrad > 150 km/s (MUSE)
  • Not Detected in X-rays
    • Lx < 1028 ergs/s
  • Roche-lobe filling stripped star?
    • M~ 2 x 10-4
  • 18.4 hours 

Rotational Period

ESO/L. Calçada

Please talk to me about:

(Things I want to learn more about)

  • Compact Binaries/Binary Evolution:

    • White Dwarfs Binaries and LISA
    • Common Envelope
    • Stripped Stars (e.g. sdB, WR, ...)
    • Products  of Binary Evolution (e.g. Barium Stars, R CrB, ELMs ...)
    • Halo vs Thick Disk Population (Gaia):
  • Star Clusters (GCs     ):
    • LISA background
    • WD binaries in GCs (Binary Evolution)
  • Time-Series Analysis:
    • Methods:
      • Gaussian Process
        • Flickering/QPOs/Magnetism in Symbiotics
      • Classification (unsupervised):
        • Dynamic time warping/The information bottleneck method
        • Where are all the AM CVns?

Evolutiocn Estrlar

 

Evolutiocn Estrlar

 

https://youtu.be/CouFXgUNK-M

 

https://pages.uoregon.edu/jimbrau/astr122-2015/Notes/Chapter20.html#lowm

Low Mass Star

Ciclo de Vida del Sol

Tipo G

https://www.astronomy.ohio-state.edu/thompson.1847/1144/Lecture15.html

Low Mass Star

Ciclo de Vida del Sol

Mirror Principle

Low Mass Star

Ciclo de Vida del Sol

Red Giant Branch

Low Mass Star

Ciclo de Vida del Sol

AGB

Low Mass Star

Ciclo de Vida del Sol

Planetary Nebula

Low Mass Star

Ciclo de Vida del Sol

White Dwarf

Low Mass Star

Ciclo de Vida del Sol

White Dwarf

Low Mass Star

Ciclo de Vida del Sol

White Dwarf

Low Mass Star

 

Clusters

https://youtu.be/wbvgjzW3Xz0

Manuel Pichardo Marcano (he/him)

Things I Love

Things I Hate

  • Dominican Republic
  • Astronomy
  • Chess, Xiangqi, Shogi, Go
  • Time-series/Light-Curves
  • Globular Clusters
  • Binary Evolution
  • White Dwarfs
  • Super Conservative Country
  • No Dominican Astronomers
  • Cooking (but love eating)
  • TESS data systematics
  • Crowded photometry (Dolphot)
  • I love all Astro
  • I love all Compact Objects

Caltech

AM CVn

Cataclysmic Variables

White Dwarf

White Dwarf

White Dwarf

Main Seq.

Accreting White Dwarf Binaries

Cataclysmic Variables

AM CVn

  • Main Sequence Star
  • Porb ~ 80 min - 10 hours
  • Outbursts:
    • 2-20 days
    • Disk instability model+ (DIM)
  • >1000 in the galactic field
  • Predicted large # in old Star Clusters
  • White Dwarf/Helium Star
  • Porb ~ 5 - 70 min
  • Outburts:
    • weeks?
    • DIM?
  • ~70 in the galactic field

Mark A. Garlick

Caltech

AM Canum Venaticorum AM CVn

  • White dwarf + White dwarf

  • White dwarf + He Star

  • Orbital Period: 5-70 minutes

  • Rare: 70 Galactic field

Caltech

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

Luminosity

Period (min)

High state (high Ṁ)

  • Hot ionized disk

Outbursting System

~20

~10

~40-60 (?)

Low state (low Ṁ)

  • Cold stable disk

Caltech

Outbursts

Pichardo Marcano et al. (2021)

SO duration

  • 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

PTF1 J0719+4858

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

  • 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)

rebrightening

SDSS J113732+405458

 Enhanced mass transfer

Rivera Sandoval et al. (2021)

Porb = 26.7 min

Porb ~ 60 min

Superoutburst duration vs Porb

Pichardo Marcano et al. (2021)

Cataclysmic Variables

  • White dwarf primary

  • "Main-sequence" donor

  • Roche-lobe overflow

  • Accretion disk (non-magnetic)

  • Highly Variables:

    • Dwarf novae

      • 2-8 mag outburst

      • 10-100 increase in L

Looking of CVs in GCs

NASA, ESA, H. Richer and J. Heyl (University of British Columbia), and J. Anderson and J. Kalirai (STScI)

Binaries in Globular Clusters

  • Globular Clusters
    • The binary population drives the dynamical evolution of GCs
  • Cataclysmic Variables:
    • Large (predicted) sample at known distance
    • Potentially very different from field CVs
    • A lot of open questions
  • Gravitational Waves:.
    • White dwarf degenerate sources for LISA

Finding CVs in X-rays and UV

  • Advantages of X-ray Searches:

    • Avoid crowding
  • Disadvantages:

    • Small FoV (FUV)
    • Lx ≥ 1029 ergs/s

Significant X-ray bias

X-ray: NASA/CXC/CfA/J.Grindlay & C.Heinke; Optical: ESO/Danish 1.54-m/W.Keel et al.

Summary CVs in GCs

  • Few of CVs per cluster

  • X-ray biased sample:

    • Lx > 1029ergs/s

  • Dearth of DNe:

    • Only 17 confirmed

  • Core-collapsed:

    • Bimodal population

  • Non core-collapsed:

    • 1 faint population

  • Period distribution?

    • 16 known periods

Need more detections. Need more Periods

All Magnetics ?

  • HST Archive
  • 7 Globular Clusters
  • Many Exposures
  • Different properties
    • Metallicity
    • Core-collapsed
    • Non core-collapsed

SCOVaS: Survey for Compact Objects and Variables

  

Preliminary Results

NGC 6397

  • Closest Core Collapse
  • Second Closest
    • 2.4 kpc
    • 15 CV candidates
    • 2 Pulsars

Preliminary Results

NGC 6397

Where are all the CVs?

We haven't found new

X-ray faint CVs

Spoiler Alert!

Other Binaries

Credits: NASA/Rivera Sandoval

Main et al 2018 (Nature)

Redback 'spider' Pulsar

Redback  Pulsar

A new candidate Redback MSP

Pichardo Marcano et. al (2021a)

  • Porb 1.96 days
  • Longest Porb for Redback in GCs
  • Missed MSP in Pulsar Searchers
    • Confirmed by Zhang et al. (2022)

Magnetic He WD Candidate

  • Vrad > 150 km/s (MUSE)
  • Not Detected in X-rays
    • Lx < 1028 ergs/s
  • Roche-lobe filling stripped star?
    • M~ 2 x 10-4
  • 18.4 hours 

Rotational Period

ESO/L. Calçada

Please talk to me about:

(Things I want to learn more about)

  • Compact Binaries/Binary Evolution:

    • White Dwarfs Binaries and LISA
    • Common Envelope
    • Stripped Stars (e.g. sdB, WR, ...)
    • Products  of Binary Evolution (e.g. Barium Stars, R CrB, ELMs ...)
    • Halo vs Thick Disk Population (Gaia):
  • Star Clusters (GCs     ):
    • LISA background
    • WD binaries in GCs (Binary Evolution)
  • Time-Series Analysis:
    • Methods:
      • Gaussian Process
        • Flickering/QPOs/Magnetism in Symbiotics
      • Classification (unsupervised):
        • Dynamic time warping/The information bottleneck method
        • Where are all the AM CVns?

Also interested in:

  • TESS:
    • Transients
    • Crowding
    • Symbiotics
  • Halo vs Thick Disk:
    • Halo CVs
    • Halo AM CVns?

Data from Peters (2008)

Blue Variables

  • Periodicity Search:
    • Lomb-Scargle
    • Phase Dispersion Minimization
  • False Alarm Probability < 10-8

NGC 6397

  • Pipeline to find interesting objects:
    • CMD Position and Periodicity/Variability Searches
  • We were able to recover all known CV Candidates
  • Found Orbital Period Redback Pulsar
  • Detached White Dwarf-Red Dwarf
  • First Magnetic He Core WD in GCs
  • Many more variables to analyze...

Where are all the CVs?

Preliminary Results

M 92

  • WFPC-2
  • 2008-01-25 to 2008-01-30:
    • 76 Exposures
    • F555W
    • Exp time: 10 s

Preliminary Results

NGC 6397

  • WFPC-2
  • March-April 2005:
    • 126 orbits
    • F814W, F606W and F336W
    • Exp time: 500-700 s

He WD Candidate

 Pichardo Marcano et al. (2023)

HACKS CMD

 Data: Libralato et al. (2022)

Also interested in:

  • Magnetic White Dwarfs:
    • A Magnetic Extremely Low-Mass WD in a Globular Cluster?
    • Magnetic WDs in Symbiotics from TESS:
      • Spin-up?

Data from Peters (2008)

  • 18.4 hours 
  • Halo vs Thick Disk:
    • Halo CVs:
      • Not Period Bouncers
    • Halo AM CVns

Pichardo Marcano et al. (2023)

Z And

28 min to 26.7 min in 20 Yr

BF Cyg (88 min)

He WD Candidate

Tracks from Althaus et al. (2009)

0.16 M☉

 0.22  M⊙

0.52 M⊙

  • 18.4 hours 

He WD Candidate

Magnetic He WD Candidate

  • Binary: Vrad > 150 km/s (MUSE)
  • Not Detected in X-rays
    • Lx < 1028 ergs/s
  • Not an Roche-lobe filling stripped star
    • M~ 2 x 10-4
  • 18.4 hours 

Rotational Period

ESO/L. Calçada

He WD Candidate

 Pichardo Marcano et al. (2023)

MUSE spectrum

Data from Husser et al. (2016), Kamman et al. (2016)

  • 5.3 hours 

Variable and No Hα Excess

  • Not Detected in X-rays
  • 0.2 Δmag in F336W
  • No Hα in Excess
  • Periodicity
    • 5.3 hours 

Variable WD Candidate

 Pichardo Marcano et al. (in prep.)

HUGS CMD

Data: Piotto et al.(2015)/ Nardiello et al. (2018)

Variable WD Candidate

 Pichardo Marcano et al. (in prep.)

HUGS CMD

Data: Piotto et al.(2015)/ Nardiello et al. (2018)

AM CVn Donors

van Roestel et al. 2022

q = M2/M1

0.0125 < q < 0.18

M2 = Donor

AM CVn Donors

Coleman et al. 2018

0.0125 < q < 0.18

<Rd> ~1010cm

q = M2/M1

AM CVn Donors

Coleman et al. 2018

0.0125 < q < 0.18

<Rd> ~1010cm

q = M2/M1

Mass-transfer rates vs orbital period

Mass-transfer rates vs orbital period

Magnetic He WD Candidate

 Pichardo Marcano et al. (2023)

  • 18.4 hours

  • 0.16 M☉

  • 0.24 R☉
  • 0.11 Gyr
  • Teff 7586 K
  • log g = 4.9

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

Compact Binaries Surveys

2- SCOVaS: Survey for Compact Objects and Variables

 

Pichardo Marcano et al. (2021a)

Pichardo Marcano et al. (2023)

   Pichardo Marcano et al. (in prep.)

 

1- TACOS: TESS AM CVn Outbursts Survey

Pichardo Marcano et al. (2021b)

Caltech

NASA

  • Color Evolution

PTF1 J0719+4858

Pichardo Marcano et al. (2021)

ZTF

SO

NO

SO

NO

rebrightening

rebrightening

  • Precursor
  • Echo Outbursts
  • DIM with Enhanced Mass Transfer  (e.g. Hameury & Lasota 2021)

SDSS J1043+5632

ZTF

TESS

  • Precursor
  • Echo Outbursts
  • DIM with Enhanced Mass Transfer  (e.g. Hameury & Lasota 2021)

SDSS J1043+5632

ZTF

TESS

PTF1 J0719+4858:

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

Color Evolution

Pichardo Marcano et al. (2021)

Accreting White Dwarf Binaries

Cataclysmic Variables

AM CVn

  • Main Sequence Star
  • Porb ~ 80 min - 10 hours
  • Outbursts:
    • 2-20 days
    • Disk instability model+ (DIM)
  • >1000 in the galactic field
  • Predicted large # in old Star Clusters
  • White Dwarf/Helium Star
  • Porb ~ 5 - 70 min
  • Outburts:
    • weeks?
    • DIM?
  • ~70 in the galactic field

Mark A. Garlick

Caltech

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)

rebrightening

SDSS J113732+405458

 Enhanced mass transfer

Rivera Sandoval et al. (2021)

Color Evolution

PTF1 J0719+4858

SDSS J113732+405458

 Enhanced mass transfer

  • Similar to Dwarf Novae
    • Hameury et al. (2020)

  • Similar SDSS J1411+4812
    • Rivera Sandoval et al. (2021)
  • Compare to SDSS 1137/SDSS 0807
    • Rivera Sandoval et al. (2021)

Pichardo Marcano et al. (2021)

Rivera Sandoval et al. (2021)

AM CVns

  •  Helium Rich and Know to go into outburts

Kupfer et. al (2013)

Duffy 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)

AM Canum Venaticorum AM CVn

  • White dwarf + White dwarf

  • White dwarf + He Star

  • Orbital Period: 5-70 minutes

  • Rare: 70 Galactic field

Caltech

Caltech

  • Porb 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

AM CVns

  •  Helium Rich and (some) known to go into outbursts

Kupfer et. al (2013)

Duffy et. al (2021)

Color Evolution

PTF1 J0719+4858

SS Cyg

Cataclysmic Variable

Hameury et al. (2020)

  • Similar to Dwarf Novae
    • Hameury et al. (2020)

  • Similar SDSS J1411+4812
    • Rivera Sandoval et al. (2021)
  • Compare to SDSS 1137/SDSS 0807
    • Rivera Sandoval et al. (2021)

Pichardo Marcano et al. (2021)

rebrightening

Type of Super Outbursts

Osaki et al. (2005)

High Mass Ratio

DIM

Cataclysmic Variables

  • Evolution Superhump

Pichardo Marcano et al. (2021)

Caltech

  • Porb 20 to ~ 60 minutes (?)

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

    • SO: Superhumps (periodic brightness variation )

  • Disk instability model (DIM)

    •  Constant Mass transfer rate

    • Tidal-thermal disk instability model

Outbursting Systems

Caltech

  • Porb 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

Place Constraints

Constraint Empirical Relationships

  1. Trec ∝ Porb7.35
  2. Tdur ∝ Porb4.54
  3. Δ mag ∝ Porb
  4. Ground-Based:
    1. PTF/CRTS
    2. ZTF
    3. LINEAR

Levitan et al. 2015

See also Duffy et al. 2021

  1. Trec ∝ Porb7.35
  2. Tdur ∝ Porb4.54
  3. Δ mag ∝ Porb
  4. Ground-Based:
    1. PTF/CRTS
    2. ZTF
    3. LINEAR

Levitan et al. 2015

See also Duffy et al. 2021

Need detailed short-term variability

Constraint Empirical Relationships

Long-term monitoring

Pichardo Marcano et al. (2021)

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

Gaia16all

Type of Super Outbursts

Osaki et al. (2005)

High Mass Ratio

DIM

Cataclysmic Variables

Pichardo Marcano et al. (2021)

See also Duffy et al. (2021)

Evolucion Estelar

By mmarcano22

Evolucion Estelar

  • 100