Search Publications
Identification of young nearby runaway stars based on Gaia data and the lithium test†
Torres, Guillermo; Mugrauer, Markus; Lux, Oliver +6 more
Young nearby runaway stars are suitable to search for their place of origin and possibly associated objects, for example, neutron stars. Tetzlaff et al. (2011) selected young (≤50 Myr) runaway star candidates from Hipparcos, for which they had estimated the ages from the location in the Hertzsprung-Russell diagram and evolutionary models. Here, we…
Spectral energy distribution modeling of broadband emission in the pulsar wind nebula 3C 58
An, Hongjun; Kim, Seungjong
We investigate the broadband emission properties of the pulsar wind nebula (PWN) 3C 58 using a spectral energy distribution (SED) model. We attempt to match simultaneously the broadband SED and spatial variations of X‑ray emission in the PWN. We further use the model to explain a possible far‑IR feature of which a hint was recently suggested in 3C…
Observability of ultraviolet NI lines in the atmosphere of transiting Earth-like planets
France, Kevin; Cubillos, Patricio E.; Fossati, Luca +5 more
Nitrogen is a biosignature gas that cannot be maintained in its Earth-like ratio with CO2 under abiotic conditions. It has also been proven to be notoriously hard to detect at optical and infrared wavelengths. Fortunately, the ultraviolet region, which has only recently started being explored for terrestrial exoplanets, may provide new …
NLTE C and O abundances in RR lyrae stars
Wallerstein, George; Korotin, Sergey A.; Huang, Wenjin +5 more
The high excitation levels that form the O I and C I lines seen in RR Lyrae stars have long been known not to obey local thermodynamic equilibrium (LTE) statistics. We have observed 21 RR Lyrae and related stars with the Apache Point Observatory echelle spectrograph on the 3.5-m telescope and, for the first time, have derived abundances using non-…
Accuracy of magnitudes in pre‑telescopic star catalogs
Hoffmann, Susanne M.; Protte, Philipp
Historical star magnitudes from catalogs by Ptolemy (137 AD), al‑Sūfī (964), and Tycho Brahe (1602/27) are converted to the Johnson V‑mag scale and compared to modern‑day values from the HIPPARCOS catalog. The deviations (or "errors") are tested for dependencies on three different observational influences. The relation between historical and moder…
CCD UBV(RI)KC photometry of the open clusters Juchert 9 and Berkeley 97
Sung, Hwankyung; Oralhan, İnci Akkaya; Çakmak, Hikmet +3 more
The CCD UBV(RI)KC photometry of the poorly studied open clusters Juchert 9 (Juc 9) and Berkeley 97 (Be 97), which are observed with the 0.84 m telescope at the San Pedro Mártir National Observatory, México has been analyzed. For the likely cluster members, we determined the reddenings, E(B‑V) = 0.82 ± 0.04 (Juc 9) and E(B‑V) = 0.87 ± 0.05 (Be 97),…
Astrometric observations of visual binaries using 26‑inch refractor at Pulkovo Observatory during 2014–2019
Izmailov, Igor; Rublevsky, Aleksey; Apetyan, Arina
We present 18,365 astrometric observations of 290 visual binaries obtained with the 26‑inch refractor of Pulkovo Observatory during 2014–2019. The separation between components is from 1″.3 to 37″ with a median value of 4″.8. For a single observation, the mean separation error is 0″.013, and the mean position angle error is 0∘.44/ρ, where ρ is an …
Spectroscopic orbit determination of the long periodic binary system θ Cep
Mugrauer, Markus; Lux, Oliver; Bischoff, Richard +4 more
In 2015, a radial velocity monitoring campaign was started in order to redetermine and/or constrain the orbital solutions of spectroscopic binary systems. The observations were carried out at the University Observatory Jena with the Échelle spectrograph FLECHAS. The results from the main part of our target sample are already published. For the fin…
Atomic data and uncertainties with PyAtomDB
Foster, Adam R.
The Atomic Database project (AtomDB) atomic database provides access to a curated collection of atomic data, along with tools that convert this data into emissivities used in many analysis tools. We present the outline of some of the tools now available for accessing AtomDB using the new Python interface, developed to handle the larger datasets th…
Supernova remnants in nearby galaxies
Sasaki, Manami
Supernova remnants (SNRs) are the aftermath of stellar explosions, which inject large amounts of energy into the interstellar medium (ISM), carving out new structures and transferring kinetic energy to the ISM. They also act as recycling centers, which return elements processed in stars to the ISM, and cosmic particle accelerators. The evolution o…