Although the halo stars represent only 3% of the stellar content of  our galaxy, several
groups are competing to study this population of stars. In particular, these groups  are interested to 
find the most metal poor stars. I  will present the methods used to find them and show why this very metal poor stellar population is particularly interesting.

I will present a few simple tricks and tips how to do a good outreach talk and I will explain and show several simple and cheap experiments, which can spice up every outreach presentation by using simple household articles to explain complex astronomical phenomena.

I will discuss some of the current problems in planet formation and their connection to circumstellar disk properties and evolution.

Narrow-line Seyfert 1 (NLS1s) galaxies show extreme properties compared to broad-line Seyfert 1 and Seyfert 2 galaxies. Their AGN are likely to be driven by high accretion rates onto relatively low-mass black holes. NLS1s are candidates for rapidly growing black holes and strong radiation-pressure-driven feedback in the local universe. Because of their extreme properties, NLS1s may provide new insight into black hole-galaxy coevolution models and into the primary mechanisms responsible for nuclear activity.
I will summarize the current knowledge on NLS1s and provide a list of open issues for discussion. I will also outline the main motivation for our ongoing analysis of IFU spectroscopy for a sample of nearby NLS1s.

QSOs whose SEDs are reddened by dust either in their host galaxies or in
intervening absorber galaxies are to a large degree missed by optical
colour selections like the one used by SDSS. To overcome this bias against
Red QSOs, we employ a combined optical and near-infrared colour selection.
We conducted a spectroscopic follow-up campaign of a sample of candidate
Red QSOs which were selected from the overlap of the SDSS and UKIDSS
surveys, using the ALFOSC instrument at the 2.5m Nordic Optical Telescope
(NOT). Of the 106 candidates which we observed, 102 (96%) are confirmed to
be QSOs. We use a statistical algorithm to identify plausible intervening
absorption systems and find 7 such cases. We find MgII absorption systems
towards 8 QSOs, two of which are consistent with the best-fit absorber
redshift from the template fitting, as well as three Damped Lyman α
Absorbers (DLAs). Furthermore, we observe a broad variety in the QSO SEDs.
We also find QSOs with a strong excess as well as QSOs with a large
deficit at rest-frame 2μm relative to a QSO template, and discuss
potential solutions to these discrepancies. Finally, a significant
fraction of the identified QSOs shows broad absorption lines (BALs), that
allow us to study the dependence of the BAL QSO population from redshift,
reddening and luminosity. The results show a strong evolution of the BAL
QSO fraction with cosmic time, with a peak at z~2.5 where several
quantities in the Universe are also found to peak or vary. In addition,
the dependence of this fraction with reddening and luminosity provides new
constraints on the models for broad absorption origin in quasars. Overall,
our study demonstrates the high efficiency of the optical/near-infrared
selection of Red QSOs.

Planck Collaboration et al. (2013) used SDSS to assemble a catalog of ~250000 "locally brightest galaxies" - essentially central galaxies for halos ranging from sub-L* galaxies up to medium-sized galaxy clusters. They stacked the SZ signal from these halos and found an unbroken powerlaw from galaxy clusters down to galaxy groups, with a slope consistent with self-similarity -- suggesting the same physics governs the intracluster and intragroup media. We have extended this analysis by stacking these same galaxies in X-rays, using the ROSAT All-Sky Survey. We find a similar unbroken powerlaw extending all the way down to L* galaxies, although the slope of this powerlaw is significantly steeper than expected for self-similarity. We show that this single powerlaw describes both the LX-M500 relation for galaxy clusters and the LX-LK relation for galaxies. The slope, normalization, and scatter of this relation are important constraints on AGN feedback and other non-gravitational heating.

Cool evolved stars are the main source of dust in the universe. They are at the end of the stellar life that is driven by nuclear
fusion, and the mass-loss process is the main driver for the further stellar evolution toward Planetary Nebulae and core-collapse Supernovae.
They are located on the Hertzsprung Russell diagram at similarly cool effective temperatures between about 2500K and 4000K, temperatures
which are favorable conditions for molecule and dust formation. However, they encompass many orders of luminosities depending on
their initial masses and include asymptotic giant branch (AGB) stars with initial masses up to about 8 solar masses and red supergiant (RSG)
stars with initial masses above about 8 solar masses.

Observed properties of AGB and RSG stars are often qualitatively and quantitatively similar. However, these stars and their subsequent
evolutionary phases are not often discussed in the same framework, because of their different masses and luminosities. Indeed, physical processes
that lead to similar observed properties may not be the same. There are, however, some recent attempts to discuss cool evolved stars
together, such as during the upcoming Vienna AGB conference this August or an approved ESO workshop next year.

To stimulate discussions on this topic, I will summarize observational results of AGB and RSG stars obtained by optical interferometry, as well
as their comparisons to theoretical models of pulsation, convection, and the mass-loss process.

Recent observations from the BICEP2 instrument of the polarisation (B-mode) of the Cosmic Microwave Background (CMB), if confirmed, are a real breakthrough in Cosmology as they would prove the occurrence of the inflation, the period of accelerated expansion in the early Universe.

I will briefly show why measurements of the polarised/unpolarised light from the CMB are related to the physical processes occurring during the inflation and before the Hydrogen recombination: fluctuations and gravitational waves originated from quantum fluctuations.

Pre-biotic molecules such as amino acids have extensively been searched for in the interstellar medium during several decades. Glycine and other amino acids have indeed been found in meteorites and comets, suggesting that these organic compounds may have an interstellar origin. However, observational studies performed in molecular clouds (in particular, in high-mass star forming regions) have not yielded any firm detection. 

In this discussion, I will present some simple radiative transfer calculations that show that the detection of amino acids and other complex pre-biotic species could be feasible at the earliest stages in the formation of Solar-type systems with current millimeter/sub-millimeter facilities. I will also discuss the implications that these results have on the development of the Band 2 receivers of ALMA.

Transitional disks are protoplanetary disks that have developed large
central cavities or annular gaps. Although several mechanisms have been
proposed to explain these features, dynamical clearing due to tidal
interactions with low-mass companions (either brown dwarfs or giant
planets) seems to be favored by the currently available data. Therefore,
transitional disks are the best sites to search for planets in the verge
of their formation.

I will present some results of our recent JVLA observations at 7mm towards
the pre-transitional disk around HD169142. Based on our detection of two
annular gaps and a protoplanet candidate, I plan to start a discussion
about the signposts of planetary formation in this kind of disks.

One of the biggest mysteries in cosmology is Dark Energy, which is required to explain the accelerated expansion of the universe within the standard model. But maybe one can explain the observations without introducing new physics, by simply taking one step back and re-examining one of the basic concepts of cosmology, homogeneity. In standard cosmology, it is assumed that the universe is homogeneous, but this is not true at small scales (a few 100 Mpc). Since general relativity, which is the basis of modern cosmology, is a non-linear theory, one can expect some backreactions in the case of an inhomogeneous matter distribution. Estimates of the magnitude of these backreactions (feedback) range from insignificant to being perfectly able to explain the accelerated expansion of the universe. In the end, the only way to be sure is to test predictions of inhomogeneous cosmological theories, such as timescape cosmology, against observational data. If these theories provide a valid description of the universe, one expects aside other effects, that there is a dependence of the Hubble parameter on the line of sight matter distribution. The redshift of a galaxy, which is located at a certain distance, is expected to be smaller if the environment in the line of sight is mainly high density (clusters), rather than mainly low density environment (voids). Here we present a test for this prediction using redshifts and fundamental plane distances of elliptical galaxies obtained from SDSS DR8 data. In order to get solid statistics, which can handle the uncertainties in the distance estimate and the natural scatter due to peculiar motions, one has to systematically study a very large number of galaxies. Therefore, the SDSS forms a perfect basis for testing timescape cosmology and similar theories. The amazing preliminary results of this cosmological test are presented.

One of the biggest mysteries in cosmology is Dark Energy, which is required to explain the accelerated expansion of the universe within the standard model. But maybe one can explain the observations without introducing new physics, by simply taking one step back and re-examining one of the basic concepts of cosmology, homogeneity. In standard cosmology, it is assumed that the universe is homogeneous, but this is not true at small scales (a few 100 Mpc). Since general relativity, which is the basis of modern cosmology, is a non-linear theory, one can expect some backreactions in the case of an inhomogeneous matter distribution. Estimates of the magnitude of these backreactions (feedback) range from insignificant to being perfectly able to explain the accelerated expansion of the universe. In the end, the only way to be sure is to test predictions of inhomogeneous cosmological theories, such as timescape cosmology, against observational data. If these theories provide a valid description of the universe, one expects aside other effects, that there is a dependence of the Hubble parameter on the line of sight matter distribution. The redshift of a galaxy, which is located at a certain distance, is expected to be smaller if the environment in the line of sight is mainly high density (clusters), rather than mainly low density environment (voids). Here we present a test for this prediction using redshifts and fundamental plane distances of elliptical galaxies obtained from SDSS DR8 data. In order to get solid statistics, which can handle the uncertainties in the distance estimate and the natural scatter due to peculiar motions, one has to systematically study a very large number of galaxies. Therefore, the SDSS forms a perfect basis for testing timescape cosmology and similar theories. The amazing preliminary results of this cosmological test are presented.

The structure of a galaxy can tell us a great deal about its evolutionary past. However, in an era of wide-area data-intensive astronomy, robustly measuring galaxy structure on a large scale across cosmic time can prove to be challenging. I discuss some of the methods we have employed thus far within the GAMA survey to begin to tackle this problem, and in so doing, the contribution we can make to furthering our knowledge of galaxy formation and evolution on the largest scales.