In anticipation of JWST data, today’s study of early Universe galaxies focuses on preparations for efficient data handling. For that reason, in our previous work (Burgarella et al. 2021, in press), we constructed an IR template which is based mainly on the ALPINE data sample with an addition of a few other well-studied galaxies, which includes galaxies in the redshift range 4.5 $<$ z $<$ 6.2....
Here we study the flux densities at 1380, 4908 and 15365 MHz, as well as the radio spectral index distribution of 3C 84, a Double Radio source Associated with Galactic Nucleus (DRAGN). 3C 84 is the dominant giant elliptical galaxy in the Perseus cluster, and thus very interesting for our research. This famous radio galaxy Perseus A has Relaxed Double classification because it has the large...
We present one part of our long-term photometry program, targeted at studying the shape and spin state of asteroids. The CCD photometric observations were carried out in the first half of 2022 with two telescopes at the Astronomical Station Vidojevica (Serbia): 1.4m Ritchey-Chrétien-Coude "Milanković" and the 60cm Cassegrain "Nedeljković" telescope.
In this work, lightcurves, the synodical...
Milutin Milankovitch published his influential research ”Canon of Insolation and the Ice-age Problem” in Belgrade, Serbia, 1941. His work is important nowadays in terms of studying climate changes. In this paper we consider new scientific knowledge about solar insolation. Periodic solar activities such as sunspots and the magnetic field cycle or grand solar minimum/maximum affect the Earth’s...
The Commensal Radio Astronomy FAST Telescope Survey (CRAFTS) is underway. With over 2,000 hours complete (out of 11,000 planned) we have mapped significant sections of the sky visible from the Five Hundred Meter Spherical Aperture Telescope (FAST) located in Guizhou, China. The Survey itself represents a technological leap forward in radio telescope observation techniques which allows for...
In the last two decades, part of the observational time at Bulgarian National Astronomical Observatory (BNAO) Rozhen was dedicated to asteroid observations. Even though we had limited time, we collected enough information to proceed with differential photometry on many asteroids. Using a combination of lightcurves of an asteroid, gained from observations at several oppositions, we were able to...
Bulgarian National Astronomical Observatory Rozhen is located in the Rhodope Mountains at about 1750 m above sea level. The astronomical observatory is the biggest one-time Bulgarian investment in scientific infrastructure and a leading astronomical center in the South-East Europe. So far, the observatory has four telescopes: 2-m RCC multipurpose telescope equipped with four new professional...
Polarization is a property of light widely used as a source of additional information in astronomy. The primary source of polarization in the atmosphere is the scattering by gas molecules although meteorological conditions, sky pattern, underlying surface reflectance, etc. may influence the observed sky polarization. In order to explicate polarization measurements correctly, it is important to...
One of the current problems of our contemporary time is related to changes in the climate of local, as well as global scope. We offer an analysis of long-term time series of meteorological data from different weather stations in Bulgaria. The main portion of the analyzed data are monthly average values of temperature, precipitation, atmospheric pressure, and they can be related to different...
A well-known paradigm about the origin of Galactic cosmic rays (CRs) is that these high-energy particles are accelerated in the process of diffusive shock acceleration (DSA) at collisionless shocks (at least up to the so-called “knee” energy of $10^{15}$ eV). Knowing the details of injection of electrons, protons and heavier nuclei into the DSA, their initial and the resulting spectrum, is...
Big Bang Nucleosynthesis (BBN) is one of the most reliable tests of Beyond Standard Model (BSM) physics due to the remarkable concordance between the theoretically predicted and the derived from observations abundances of light elements produced primordially. Recently the primordial light elements D and He-4 were determined with higher accuracy. This allows to update and strengthen the Big...
S-Z is an effect, which consists in the inverse Compton effect of the hot electronic gas interacting with Cosmic Microwave Background (CMB) photons passing through Intra Cluster Medium (ICM). Building more accurate profiles for temperature and density of hot electronic gas, concentrated in the center of clusters of galaxies, is a constant problem in survey of Sunyeav Zel’dovich effect (SZ)....
We report BR-bands monitoring of 6 massive star candidates selected in a 10x10 sq. arcmin field in north-east quarter of the IC342 galaxy on the base of our B+H$\alpha$ images obtained with the 2m RCC telescope at NAO Rozhen, Bulgaria. We analyzed 2.3 yr BR-light curves of the objects. The candidates demonstrate photometric variations smaller than 0.2 mag, and no overall brightness changes has...
Analyzing our catalog of active-region-related activity events of solar cycle 24, we pay special attention to solar flares. In addition to Geostationary Operational Environmental Satellite (GOES) soft X-ray flare listing data that we investigated to associate solar flares with active regions, we added microwave flare observations by the Badary Broadband Microwave Spectropolarimeter (BBMS). ...
For the detection of celestial bodies near the Earth, called NEO bodies, Near Earth Object, among which are NEA asteroids, Near Earth Asteroids, several types of software and utilities have been created. This paper includes the way in which the image packets were processed, taken from the telescope, highlighting the characteristics of NEO bodies and how they were used in Astronomy, to obtain a...
