Radial-velocity observations of pulsating stars with a new

Poznań Spectroscopic Telescope

23 June 2008

Poznań Astronomical ObservatoryAdam Mickiewicz University

Poznań, Poland

Our team

R. Baranowski, P. Bartczak, W. Borczyk, W. Dimitrov, M. Fagas, K. Kamiński, T. Kwiatkowski, R. Ratajczak, A. Rożek, A. Schwarzenberg-Czerny

The „dome”

Mirors diameter – 0.4 m

Focal length – 1.8 m

Optical system – Newtonian

Diameter of the fibers – 50 m

Accesible altitudes h>24°

Mean. slewing rate 90°/min

Guiding cameras ST7

The telescope

The echellé spectrograph

Baudrand and Bohm (1992)

CCD camera:Andor DZ 4365-stage peltier cooling Temp. –95°C2048 x 2048 pix

pixel size 13.5 x 13.5μmdark current <1el/hreadout noise 2.1 el/pix

Echellé spectrograph

Spectral range:

4480 Å – 9250 Å

Resolution:

R=35000 (~8 km/s)

Acquisition box

Echellé spectrum – 64 orders

4480 Å – 9250 Å

blue range: 1pix = 0.04 Å order length = 80 Å every order adds 40 Å

middle: 1pix = 0.05 Å ~2.5 km/s order length = 100 Å every order adds 80 Å

red range: 1pix = 0.08 Å order length = 160 Å every order adds 125 Å

ThAr calibration spectrum

1400 lines

Flatfield and fringe effect

Flatfield and fringe effect

Telluric lines removal

Flux calibration

Line profiles

Sp=B1

V=1m

exp=250s

Hβ 4861 Å

Limiting magnitude - BD+39 3012C 11m.2 Sp=F5 exp=30min

28 And

δ Sct

Sp=A7III

V=5m.2

exp=600s

analysed by T. Kwiatkowski, W. Borczyk & A. Rożek

γ Peg

β Cep

Sp=B2IV

V=2m.8

exp=600sor 300s

period=3.4h

υ1=6.59 c/d

analysed by W. Borczyk

V440 Per

δ Cep

Sp=F7Ib

V=6m.3

exp=600s

analysed by A.Schwarzenberg-Czerny and M. Fagas

σpoz=136 m/s---2 harmonics---1 harmonic

Polaris

analysed by M. Fagas and K. Kamiński

okres obs. P [d] 2K [km/s] ref.

1896 – 1950 ~5-6Campbell (1899),Roemer (1965)

1899 - 1923 3.96809 Moore (1924)

1944 – 1954 3.96961 Stebbius (1946)

1981 – 1982 3.971562 ± 1

2.8 ± 0.6Arellano Ferro (1983)Kamper et al. (1984)

1987 - 1988 3.9746 ± 0.0008 1.5 ± 0.08 Dinshaw et al. (1989)

1992.41993.2

3.97268 ± 0.00011

1.555 ± 0.0561.517 ± 0.047

Hatzes & Cochran (2000)

1994.261996.96

3.97211.66 ± 0.021.68 ± 0.08

Kamper & Fernie (1998)

2005.1832006.3602007.349

3.97208 ± 0.00013

2.210 ± 0.0482.080 ± 0.0422.406 ± 0.018

Lee et al. (2008)

20083.97792 ±

0.00152.52 ± 0.03 Borowiec (2008)

Statistics

13 august 2007 - 30 may 2008

• 83 nights• 637 hours• 1080 science spectra

Colaborators

• Warsaw CAMK• Vienna Institute of Astronomy• Wrocław Astronomical Institute• Toruń Centre for Astronomy

Future perspectives

Upgrade of the telescope:

• 2 x 0.5m mirrors• simultaneous exposure of two fibers• better automatisation and remote control

Upgrade of the calibration, some ideas:

• experiment - mixing the ThAr and stellar light• Vrad accuracy increase with a iodine cell• spectral resolution increase with the EDI

interferometer

Radial velocity measurements:

• broadening function• TODCOR• spectral disentangling