Transit Timing Analysis in the HAT-P-32 system

We present the results of 45 transit observations obtained for the transiting exoplanet HAT-P-32b. The transits have been observed using several telescopes mainly throughout the YETI network. In 25 cases, complete transit light curves with a timing precision better than $1.4\:$min have been obtained. These light curves have been used to refine the system properties, namely inclination $i$, planet-to-star radius ratio $R_\textrm{p}/R_\textrm{s}$, and the ratio between the semimajor axis and the stellar radius $a/R_\textrm{s}$. First analyses by Hartman et al. (2011) suggest the existence of a second planet in the system, thus we tried to find an additional body using the transit timing variation (TTV) technique. Taking also literature data points into account, we can explain all mid-transit times by refining the linear ephemeris by 21ms. Thus we can exclude TTV amplitudes of more than $\sim1.5$min.Comment: MNRAS accepted; 13 pages, 10 figure

Photometric observations of Epsilon Aurigae during the eclipse of 2009-2011

Epsilon Aurigae is a bright binary system, in which an F0 supergiant is eclipsed by a dark disk around the companion, every 27.1 years. Although the star has been observed and studied for nearly two centuries, it remains an usolved mystery. For the latest ε Aur eclipse, which occurred in 2009-2011, an international observing campaign was organized. In this publication, multicolor BV R photometric observations obtained in the framework of this campaign, are presented. Part of these data have been corrected for atmospheric extinction and transformed to the standard Johnson's photometric system

Photometric observations of Epsilon Aurigae during the eclipse of 2009-2011

Epsilon Aurigae is a bright binary system, in which an F0 supergiant is eclipsed by a dark disk around the companion, every 27.1 years. Although the star has been observed and studied for nearly two centuries, it remains an usolved mystery. For the latest ε Aur eclipse, which occurred in 2009-2011, an international observing campaign was organized. In this publication, multicolor BV R photometric observations obtained in the framework of this campaign, are presented. Part of these data have been corrected for atmospheric extinction and transformed to the standard Johnson's photometric system

The Araucaria Project: Improving the cosmic distance scale

The book consists of a number of short articles that present achievements of the Araucaria members, collaborators, and friends, in various aspects of distance determinations and related topics. It celebrates the 20-year anniversary of the Araucaria Project, acknowledges the people who worked for its success, and popularises our methods and results among broader readership. This book is a part of a project that has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 695099.Comment: 114 pages, book published in 2021 on behalf of the Nicolaus Copernicus Astronomical Center of the Polish Academy of Sciences, to celebrate 20 years of the Arauria Projec

Emission lines in the spectrum of the symbiotic star AG Draconis from 1997 to 2003

The halo symbiotic star AG Dra has been monitored spectroscopically at the Tartu Observatory, Estonia, from September 1997 to March 2003. Altogether 189 spectra are used in the present paper. In addition, photometric UBVri observations at the Piwnice Observatory, Poland, from March 1996 to May 2003 are presented. Equivalent widths (${\it EW}$) of the strongest emission lines (Hα, Hβ, \ion{He}{ii} λ 4686, \ion{O}{vi} Raman scattered λ 6825) appear to be strongly variable, and in general, correlate with the U brightness of the star. No apparent correlation with the orbital motion of the binary system was found, except for Hβ in the quiescent state. At the same time, there is a clear convergence of the high values of ${\it EW}$ to certain phases according to the shorter photometric period (378.5 days) proposed by Bastian (1998) and the pulsational period of the cool giant (355.27 days) by Gális et al. (1999). Higher resolution spectra show variability of the Hα profiles, with weak absorption component on the blue wing of the line around photometric minimum if the star is in quiescent state. The significant role of the cool giant in the activity of AG Dra is discussed

A new look at the long-period eclipsing binary V383 Scorpii

Context. The system V383 Sco was discovered to be an eclipsing binary star at the beginning of the twentieth century. This system has one of the longest orbital periods known (13.5 yr) and was initially classified as a ζAur-type eclipsing variable. It was then forgotten about for decades, with no progress made in understanding it. Aims. This study provides a detailed look at the system V383 Sco, using new data obtained before, during, and after the last eclipse, which occurred in 2007/8. There was a suspicion that this system could be similar to eclipsing systems with extensive dusty disks like EE Cep and ε Aur. This and other, alternative hypotheses are considered here. Methods. The All Sky Automated Survey (ASAS-3) V and I light curves have been used to examine apparent magnitude and colour changes. Low- and high-resolution spectra have been obtained and used for spectral classification, to analyse spectral line profiles, as well as to determine the reddening, radial velocities and the distance to the system. The spectral energy distribution (SED) was analysed using all available photometric and spectroscopic data. Using our own original numerical code, we performed a very simplified model of the eclipse, taking into account the pulsations of one of the components. Results. The low-resolution spectrum shows apparent traces of molecular bands, characteristic of an M-type supergiant. The presence of this star in the system is confirmed by the SED, by a strong dependence of the eclipse depth on the photometric bands, and by the nature of pulsational changes. The presence of a very low excitation nebula around the system has been inferred from [O 

Gaia18aen: First symbiotic star discovered by Gaia

Context. Besides the astrometric mission of the Gaia satellite, its repeated and high-precision measurements also serve as an all-sky photometric transient survey. The sudden brightenings of the sources are published as Gaia Photometric Science Alerts and are made publicly available, allowing the community to photometrically and spectroscopically follow up on the object. Aims. The goal of this paper is to analyze the nature and derive the basic parameters of Gaia18aen, a transient detected at the beginning of 2018. This object coincides with the position of the emission-line star WRAY 15-136. The brightening was classified as a “nova?” on the basis of a subsequent spectroscopic observation. Methods. We analyzed two spectra of Gaia18aen and collected the available photometry of the object covering the brightenings in 2018 and also the preceding and following periods of quiescence. Based on this observational data, we derived the parameters of Gaia18aen and discussed the nature of the object. Results. Gaia18aen is the first symbiotic star discovered by Gaia satellite. The system is an S-type symbiotic star and consists of an M giant of a slightly super-solar metallicity, where Teff ∼ 3500 K, a radius of ∼230 R⊙, and a high luminosity L ∼ 7400 L⊙. The hot component is a hot white dwarf. We tentatively determined the orbital period of the system ∼487 d. The main outburst of Gaia18aen in 2018 was accompanied by a decrease in the temperature of the hot component. The first phase of the outburst was characterized by the high luminosity L ∼ 27 000 L⊙, which remained constant for about three weeks after the optical maximum, later followed by the gradual decline of luminosity and increase of temperature. Several re-brightenings have been detected on the timescales of hundreds of days

Imaging of Clear Cell Renal Carcinoma with Immune Checkpoint Targeting Aptamer-Based Probe

Immune checkpoint targeting immunotherapy has revolutionized the treatment of certain cancers in the recent years. Determination of the status of immune checkpoint expression in particular cancers may assist decision making. Here, we describe the development of a single-stranded aptamer-based molecular probe specifically recognizing human PD-L1. Target engaging aptamers are selected by iterative enrichment from a random ssDNA pool and the binding is characterized biochemically. Specificity and dose dependence is demonstrated in vitro in the cell culture using human kidney tumor cells (786-0), human melanoma cells (WM115 and WM266.4) and human glioblastoma LN18 cancer cells. The utility of the probe in vivo is demonstrated using two mouse tumor models, where we show that the probe exhibits excellent potential in imaging. We postulate that further development of the probe may allow universal imaging of different types of tumors depending on their PD-L1 status, which may find utility in cancer diagnosis