arXiv subjects

Robert Jaros

Publications and source records attributed to Robert Jaros.

4 recordsLinked to original sources

arXiv2026

Joint Observations of PTPS Targets (JOTA). Combined spectroscopic and photometric analysis of 16 SB1 systems

Context. The Pennsylvania-Toru\'n Planet Search, which operates on a sample of $\sim$1000 northern-hemisphere stars, has been underway since 2004. Stars with radial velocity (RV) amplitudes exceeding 2 km s$^{-1}$ represent a backup subprogram sample dedicated to monitoring binary stars with multiple instruments. Aims. We used almost 21 years of combined RV measurements to search for Doppler signals consistent with stellar or brown dwarf companions and to produce a catalog of both known and previously unpublished binary stars in our planet-search sample. Methods. We analyzed the combined RV measurements, searching for stellar companions and obtaining orbital solutions for both known and new binary systems. We also searched for periods in available long-term photometric monitoring data from All Sky Automated Survey (ASAS), and applied Gaia astrometric data whenever available. Results. We report the results of long-term RV monitoring of 16 systems: new detections of low-mass companions to 11 stars and updated orbital elements based on combined sets of our new and literature data for five systems. For two objects (TYC 3318-00789-1 and TYC 3318-01538-1), we find evidence of activity or the influence of another unseen companion, possibly due to line-profile variations or unresolved spectral contamination. We present true masses for three systems in our sample: TYC 1931-1040-1, TYC 3451- 1449-1, and TYC 3667-1636-1. We obtained these masses using Gaia DR3 non-single star data.

astro-ph.SR↗

arXiv2025

Planetary-mass companions to a retired B star BD+37 3172 and a retired F star BD+42 2315

Radial velocity searches may lead to detection of exoplanets at large orbital separations only if long-enough time-series of data are available. Therefore publication of precise measurements collected in the past is very valuable even if not successfully completed with a definitive detection. Here we present 309 precise ($\sigma$RV$\approx$5-7 m s$^{-1}$) multi-epoch radial velocities for 28 stars observed with the Hobby-Eberly Telescope and its High Resolution Spectrograph between 2004 and 2013. Based on the observations gathered we present a low mass companion ($m_{p}\sin{i}$ = 10.6 $M_{J}$ in 1887.76 $\pm$ 0.01 d, 4.65 au orbit with $e$ = 0.59 $\pm$ 0.01) to a K giant BD+37 3172 ($M$=3.75$\pm$ 0.86 M$_{\odot}$), and a planetary mass companion (m$_{p}\sin{i}$=0.55 M$_{J}$ in 123.05$\pm$0.04 day, 0.55 au orbit with e=0.73$\pm$0.03) to a K giant BD+42 2315 ($M$=1.38$\pm$ 0.30 M$_{\odot}$). We also present two preliminary detections of new spectroscopic binaries: BD+56 2957 (K5) and HD 236555 (G5).

astro-ph.SR↗

arXiv2025

Low-mass companions to nine stars

We present an independent spectroscopic and radial velocity analysis for nine stars from the Pennsylvania-Toru\'n Planet Search. For BD+24 4697, we present an updated true companion's mass (0.16$\pm$0.02 \, M$_{\odot}$), as well as evidence of stellar activity. For BD+54 1640 and BD+65 1241 we present true masses of companions, $m = 0.15 \pm 0.04\,M_\odot$ and $m = 0.091 \pm 0.005\,M_\odot$, respectively. For BD+63 974 and BD+69 935 we find low mass companions with $m \sin i = 0.046 \pm 0.001\,M_\odot$ and $m \sin i = 0.090 \pm 0.005\,M_\odot$. For BD+52 1281, BD+54 1382, TYC 2704-2680-1, and TYC 3525-02043-1 we present evidence of low-mass companions with $m \sin i$ of 0.115 $\pm 0.006\,M_\odot$, 0.083 $\pm 0.007\,M_\odot$, 0.279 $\pm 0.009\,M_\odot$, and $0.064 \pm 0.006\,M_\odot$, respectively. Consequently, BD+54 1382, BD+63 974, BD+65 1241, BD+69 935 and TYC 3525-02043-1 appear to be Brown Dwarf host candidates.

astro-ph.SR↗

arXiv2020

Transport of dust grain particles in the accretion disk

Entrainment of dust particles in the flow inside and outside of the proto-planetary disk has implications for the disk evolution and composition of planets. Using quasi-stationary solutions in our star-disk simulations as a background, we add dust particles of different radii in post-processing of the results, using our Python tool DUSTER. The distribution and motion of particles in the disk is followed in the cases with and without the backflow in the disk. We also compare the results with and without the radiation pressure included in the computation.

astro-ph.SR↗