V371 Per - A Thick-Disk, Short-Period F/1O Cepheid

V371 Per was found to be a double-mode Cepheid with a fundamental mode period of 1.738 days, the shortest among Galactic beat Cepheids, and an unusually high period ratio of 0.731, while the other Galactic beat Cepheids have period ratios between 0.697 and 0.713. The latter suggests that the star has a metallicity [Fe/H] between -1 and -0.7. The derived distance from the Galactic Plane places it in the Thick Disk or the Halo, while all other Galactic beat Cepheids belong to the Thin Disk. There are indications from historical data that both the fundamental and first overtone periods have lengthened.Comment: Accepted for publication in MNRA

Optical Imaging of Nova Shells and the Maximum Magnitude-Rate of Decline Relationship

An optical imaging study of recent 30 novae has been undertaken using both ground-based and space-based observations. Resolved shells have been detected around 9 objects in the ground-based data, while another four objects have shells detected by HST observations; for RW UMi, we fail to detect a shell which was observed five years earlier. Images in H-alpha, and when appropriate [O III], are shown, and finding charts for novae without shells are given if no published chart is available. Expansion parallaxes for all systems with shells are derived, and absolute magnitudes for a total of 28 objects are presented, along with a discussion of the maximum magnitude-rate of decline relation. We find that separate linear fits for fast and slow novae may be a better representation of the data than a single, global fit. At minimum, most novae have similar magnitudes as those of dwarf novae at maximum and novalike stars.Comment: 39 pages, 5 ps-figures, 13 jpg-figures. Accepted for publication in the Astronomical Journal (October 2000

A radio-pulsing white dwarf binary star

White dwarfs are compact stars, similar in size to Earth but ~200,000 times more massive. Isolated white dwarfs emit most of their power from ultraviolet to near-infrared wavelengths, but when in close orbits with less dense stars, white dwarfs can strip material from their companions, and the resulting mass transfer can generate atomic line and X-ray emission, as well as near- and mid-infrared radiation if the white dwarf is magnetic. However, even in binaries, white dwarfs are rarely detected at far-infrared or radio frequencies. Here we report the discovery of a white dwarf / cool star binary that emits from X-ray to radio wavelengths. The star, AR Scorpii (henceforth AR Sco), was classified in the early 1970s as a delta-Scuti star, a common variety of periodic variable star. Our observations reveal instead a 3.56 hr period close binary, pulsing in brightness on a period of 1.97 min. The pulses are so intense that AR Sco's optical flux can increase by a factor of four within 30 s, and they are detectable at radio frequencies, the first such detection for any white dwarf system. They reflect the spin of a magnetic white dwarf which we find to be slowing down on a 10^7 yr timescale. The spin-down power is an order of magnitude larger than that seen in electromagnetic radiation, which, together with an absence of obvious signs of accretion, suggests that AR Sco is primarily spin-powered. Although the pulsations are driven by the white dwarf's spin, they originate in large part from the cool star. AR Sco's broad-band spectrum is characteristic of synchrotron radiation, requiring relativistic electrons. These must either originate from near the white dwarf or be generated in situ at the M star through direct interaction with the white dwarf's magnetosphere

Urogenital disease morbidity among the adult and child population of the Osh Region for the period from 2010 to 2019

It is presented the results of a study on the prevalence, structure, and trends in urogenital diseases in the adult population of the Osh Region of Kyrgyzstan for the period between 2010 and 2019. Official statistics on morbidity provided by the National Statistical Committee of the Kyrgyz Republic are used as materials for the study. Information on the main indices characterizing adult morbidity is selected and summarized, and dynamic statistical analysis of the data is performed. The data analysis demonstrates that the highest morbidity of urogenital diseases in the Osh Region was registered in 2017, and the lowest – in 2019