The differences between physical conditions in solar faculae and those in sunspots and quiet photosphere (increased temperature and different magnetic field topology) suggest that oscillation characteristics in facula areas may also have different properties. The analysis of 28 time series of simultaneous spectropolarimetric observations in facula photosphere (Fe I 6569 Å, 8538 Å) and chromosphere (Hα, Ca II 8542 Å) yields the following results. The amplitude of five-minute oscillations of line-of-sight (LOS) velocity decreases by 20 -40% in facula photosphere. There are only some cases revealing the inverse effect. The amplitude of four-to five-minute LOS velocity oscillations increases significantly in the chromosphere above faculae, and power spectra fairly often show pronounced peaks in a frequency range of 1.3 -2.5 mHz. Evidence of propagating oscillations can be seen from space -time diagrams. We have found oscillations of the longitudinal magnetic field (1.5 -2 mHz and 5.2 mHz) inside faculae.

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A small-scale flare SOL2012-09-21T02:19 (B2) occurred in a spotless active region that we observed at a groundbased telescope equipped with a spectrograph. During the flare, we registered an increase in absorption in the He i 10830Å line by 25%, while other chromospheric and coronal spectral lines demonstrated increase in brightness at the same location. This phenomenon called negative flare had rarely been observed at the Sun before. In this paper, we describe the morphology of this flare and investigate its dynamics based on our spectral observations and space imaging data. The Hα and He i 10830Å lines reach their extreme intensities 5 and 6 minutes after the 171Å line. The brightening first occurred in the 171Å and 193Å Solar Dynamics Observatory (SDO) channels followed by the 94Å, 304Å, and 1600Å signals ∼2 minutes after (for the maximum phases). However, the abrupt changes in line-of-sight (LOS) velocities in the chromospheric lines occur simultaneously with the intensity changes in the 304Å and 1600Å lines: we observed a downward motion that was followed by two upward motions. The measured horizontal speed of the perturbation propagation was close to 70 km s −1 both in the chromospheric and coronal lines.We assume that we observed the photoionization-recombination process caused by UV radiation from the transition region during the coronal flare. With this, we point out the difficulties in interpreting the time lag between the emission maximum in the SDO UV channels and the second absorption maximum in the He i 10830Å line.

One of the most important problems of modern solar physics is the observation of the small-scale structure of the solar atmosphere at various heights (including the chromosphere and corona) in different spectral lines. Such observations can be made only with large solar telescopes whose main mirror has a diameter of at least 3 m. Currently, several large solar telescopes are under construction or development in the world. In 2013 in Russia, the work began on the development of a national large solar telescope with a mirror 3 m in diameter (LST-3), which is a part (subproject) of the National Heliogeophysical Complex of the Russian Academy of Sciences. The telescope is planned to be located in the Sayan Solar Observatory at an altitude of more than 2000 m. The choice was made in favor of the classic axisymmetric Gregory optical layout on an alt-azimuth mount. The scientific equipment of LST-3 will consist of several systems of narrow-band tunable filters and spectrographs for various wave ranges. The equipment will be placed both in the main coude focus on a rotating platform and in the Nasmyth focus. To achieve a diffraction resolution, high-order adaptive optics (AO) will be used. It is assumed that with a certain modification of the optical configuration, LST-3 will work as a 0.7 m mirror coronograph in near infrared lines and can also be used for observing astrophysical objects in the nighttime.

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