Some planetary nebulae (PNe) show microstructures of low ionization located in their outer regions, i.e. external to the bright rim defined by the fast vs. slow...

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We have observed a sample of "ordinary" quasars, selected only on the grounds of their relative brightness in the visible, with the Turku Photopolarimeter on...

Studying Broad Absorption Line Quasars (BAL QSOs) is interesting because they probe the physics of the AGN environment, and because AGN outflows are important...

In addition to the well-known 11-year solar cycle, the Sun's magnetic activity also shows significant variation on shorter time scales, e.g. between one and two...

Simulation of encounters of disk galaxies (Barnes 2002, MNRAS, 333, 481) shows that the newly formed disks are often warped, many have rather complex kinematics...

The effect of temperature fluctuations in the spectra of ionized nebulae was firstly explored by Peimbert (1967). Since then, the problem of their existence has...

We study the photoionization of the Extended Narrow Line Region (ENLR) using three anisotropic radiation fields: (1) a geometrically thick accretion disk; (2) a...

We present the visible spectrum of asteroid-comet transition object 133P/Elst-Pizarro (7968), the first member of the new population of objects called Main Belt...