IAC science with the prototype SONG node

at Tenerife

Katrien Uytterhoeven

research group ‘Solar and Stellar Seismology and Extrasolar

planet searches’

Interests in SONG:

* the Sun-as-a-star* solar-like stars* red giants* SdB stars* δ Sct, γ Dor* β Cep, SPB* OB supergiants* binaries with pulsating components

* follow-up of planet candidates

Seis

molo

gy

pla

nets

(7 staff, 2 PostDocs, 3 PhD)

Massive main-sequence pulsators

= γ Dor, δ Sct, SPB, β Cep

Problem: mode-ID does not rely on regularity of frequency spectrum

Seismic study requires identified (l,m) modes!

δ Sct HD50844

Mode-ID via line-profile analysis!

(l,m)* amplitude and phase

distribution across line-profile* velocity moments

GOAL: SONG RV time-seriesa)mode-identification!

b) test and improve seismic models

Sun-as-a-star: SONG and Mark-I

Mark-I * operational at Obs. Teide since 1976

* full-time monitoring since 1984

* RV of the Sun through potassium KI 769.9 nm line

* sampling rate: 2sec

GOAL: daytime solar spectra with SONG

a) compare simultaneous (same site!) Mark-I and SONG observations (resample to same sampling rate)

b) evaluate quality and sensitivity of SONG solar observations

Planet transits

See talk by Brandon!

Use SONG photometry to confirm transit candidates through color changes during transit

> 50 staff scientists

> 65 post-docs

> 35 PhD students

Interests in SONG from IAC research groups other than the

group on ‘Solar and Stellar Seismology and

Extrasolar planet searches’

twilight sky spectrumHET McDonald

observatory

* 1 yr solar orbitampl=0.507 km s-1

* 1 d Earth orbit(not well covered)

+ other deviations!

i. Wavelength variations in Solar spectral lines

ΔT = 1750 days

Origin of deviations?

* changes in granulation properties along solar cycle

* presence of planets e.g. Jupiter: 13 m s-1 over 12yr

GOAL: twilight sky spectra with SONG and I2 cell

a) investigate wavelength stability of the solar spectrum

b) demonstrate that deviations due to a Jupiter-size planet can unambigously be found

c) study stellar activity

* Compact Binaries (Porb~hrs), primary is compact object (neutron star, black hole).

* Roche-lobe overflow, matter accreted via accretion disk.

* Inner accretion disk gives rise to X-rays.

* optical emission due to Reprocessing of X-rays in outer accretion disk

* Different optical wavelengths probe different parts of the outer accretion disk

ii. Low mass X-ray binariesRémon Cornelisse

Large night to night changes in lightcurve morphology

Goal: ~1 week continuous multi-colour photometric monitoring with the SONG network

a) understand the origin of the lightcurve changes b) understand physics of the accretion disk

Origin? changes in accretion disk due to precession or the presence of a warp?

Nova = thermonuclear explosions on surface of white dwarf accreting mass in a close binary

questions:

* model that fits at all wavelengths ?

T Pyx, lightcurve

Mag

MJD - 2450000

* brightening (< V=10mag few weeks)

* FeII or He/N line absorption

* origin of absorption lines?

* mysterious absorption systems (THEA)

iii. Classical Novae at maximum light

Alessandro Ederoclite

T Pyx, FIES spectraTim

e

15.04.2011

30.05.2011

GOAL: few SONG spectra per day (without I2 cell) during max light of

novae

follow-up optical thick and thin phase

a) describe chemistry

b) describe dynamics of explosion

Well-detached EBs are best calibrators for models of stellar structure and evolution

accurate orbital parameters, M*, R* !

BUT! spectral chemical analysis is lacking!

GOAL: SONG spectra (without I2 cell) of well-known, bright, well-

detached EBs at max separation

a)derive metallicity and chemical abundances of binary componentsb)calibrate models stellar structure & evolution

iv. Chemical analysis of EBs

Carlos Allende Prieto

v. Multiple populations in globular clusters

Antonino Milone

Many globular clusters show multiple sequences!

GOAL: SONG spectra of bright stars in GCs

(filling program)

derive chemical and dynamical properties

and try to solve:

a)abundance anomalies

b) multiple sequences

c)horizontal branch morphology

CMD of NGC 2808 with isochrones

vi. macroturbulent broadening in OB supergiants

Sergio Simón Díaz

pilot study!signature of collective effect of pulsations?!

OB SGs show extra line broadening:

‘macrotubulence’

origin?

GOAL: time-series of SONG

spectra of bright OB supergiants

a) understand ‘macroturbulence’

b) improve atmosphere models of OB SGs

c) first seismic studies of OB SGs!

promising!

IAC science

many interesting filling programs and additional SONG science programs

for SONG-OT!