- 1. Straizys/Sudzius (Dima, Jes):
- Syntetic Photometry, Transformation
between systems
To construct a photometric system for calassification
of white dwarfs. This needs good calibarated stpectra of white dwarfs,
and on task for the students will be to find and get hold of such
spectra. They should then be integrated through syntetic "filters" or
spectral windows to select the most ortogonal set of filters.
- 2. Sudzius/Sperauskas (Katya, Robert):
- Observe a set of stars with the 2 ch
photometer, and do a complete reduction. Data will be provided if bad weather.
- 3. Wyse (Bernhard, Oscar):
- Stellar populations
I propose a literature search on `the second parameter in globular
cluster horizontal branch morphology', and that the students write a concise summary of
the current understanding : why this is important; what is the nature of the second
parameter, and what does this tell us about how the Milky Way galaxy evolved.
- 4.Linde (Alar, Kirsten):
- Write a proposal for HST observing time.
- 5. Lindegren (Dmitry, Sasha):
- Quasar detection with GAIA.
Among the 10^9 point like objects observed by GAIA it is important to
identify as any quasars as possible for establishing a non rotating
reference frame. Faint quasars have to be identified mainly by
photometric criteria, i.e. from their unusual colours and variability.
The assignment could consist in deriving the typical QSO colours in the
GAIA broadband system as function of redshift, (Using a composite QSO
specrum as in Francis et al ApJ 373, 465, 1991) and compare with colours
for ordinary ( unreddened and reddened ) star\Using the known
photometric precision versus magnitude, estimate how well quasars can be
separated from stars as function of magnitude and redshift.
- 6.Solheim/Meistas (Rimas, Morten):
-
White dwarf Asteroseismology.
One white DA white dwarf PG 1159-03 has been observed twice with the
Whole Earth Telescope. The second run in 1993 should be analysed by the
students, and the results compared with the first one (Winget et al APJ
378,326,1991.) What changes has occured, and what does this tell us about
the star? Explain how the Whole Earth Telescope works and what results
it has obtained.
- 7. Solheim/Meistas (Lilya, Rubina):
- Searching for pulsating sdB objects.
Data: High speed photometry from NOT, July 16-23, 1999, and follow up observations
at the Moletai observatory
A set of 13 sdB objects have been observed with the method of continuous
photometry with the NOT. Each object has been bserved less than two hours
in one or more nights. The objects have all temperatures between 30 and
34 000K, which corresponds to the instability strip for the pulsating EC
14026 stars.
The students shall reduce the data, and investigate which, if any objects
are pulsators. Discuss the detection criteria and the most favourable
observational stategy to find such pulsators. Follow up observations on
one of the object is foreseen during the course, and the results should
be reduced and compared with the light curves from the NOT
- 8. Kjeldsen (Vygandas, Jianpeng):
- Time-series photometry of beta Cepehi variables in NGC 6231
Data: 128 frames in V, B, and U taken July 30/31 1999
Length of the time series: 4 hr and 24 min
Total number of CCD-frames (incl FF and Bias) : 482 1050 x 1026 pix
NGC 6231 is a very young cluster (5 Myr) and it is known to contain a
number of relative unevolved beta Cephei variables.
The data should be used to study:
- Locate the variable stars, plot light curves and determine periods.
- Study the oscillations in the three different filters, U,B,and V
- Try to reach high photometric precision in this semi-crowded field
(but the stars are not in focus! -- in order not to saturate the
chip)
- Explain what we can learn about stellar evolution of massive stars
from a study of unevolved beta Cep stars
- 9. Jorgensen/Milvang (Karlis, Eira):
- Surface Photometry of two galaxies in the Virgo
cluster
The students will derive surface photometry in two colors (R and B) for
two galaxies in the Virgo Cluster. The data are CCD images and will be
suplied in already reduced and calibarated form.
Based on the surface photometry the students will determine the effective
parameters (radius, mean surface brightness, total magnitude) colors and
the color gradient.
The project will include a discussion of uncertainties, both for the
surface photometry and the derived parameters, a discussion of the colors
and the color gradient, and a comparison with the litterature data. The
students will also discuss the characteristic residuals from the fitting
procedure in connection with the classification of the galaxies.
The project assumes that the students have a basic knowledge of IRAF.
- 10. Hagen-Thorn/Marchenco (Justas, Roy):
- Reduction and analysis of Blazar data.
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