Search Publications
New online database of symbiotic variables: Symbiotics in X‑rays
Merc, J.; Gális, R.; Wolf, M.
Symbiotic variable stars belong to an interesting class of interacting binary systems. Since the beginning of this century, the systematic search for these objects has begun, and such surveys have led to discoveries of many new objects and dozens of candidates in the Milky Way and the Local Group. As the latest catalogue of symbiotic binaries is a…
On the possibilities of classical nova identifications among historical Far Eastern guest star observations
Hoffmann, Susanne M.; Vogt, Nikolaus; Tappert, Claus
More than 100 guest star observations have been obtained by Chinese, Korean, Japanese, and Vietnamese astronomers between ∼600 BCE and ∼1690 CE. Comparing the coordinates from the information given in old texts for eight supernova recoveries with modern supernova remnant positions, we estimate the typical positional accuracy of the order of 0.3–7°…
Galaxy rotation curve from classical Cepheids
Gnaciński, Piotr
The galaxy rotation curve is usually assumed to be flat. However, some galaxies have rotation curves that are lower than the flat rotation curve. In our galaxy, the Keplerian rotation of interstellar clouds in the galactic longitude l = 135° was observed. We use a kinematic approach to derive the rotational velocity of classical Cepheids. The rota…
The new 4‑m robotic telescope
Rebolo, R.; Steele, I. A.; Harvey, E. +9 more
We present a project to build a 4‑m‑diameter telescope (New Robotic Telescope [NRT]) with fully robotic operation. The telescope will be sited at the Observatory of Roque de los Muchachos in the island of La Palma (Spain). When it enters into operation in 5 years' time, it will be likely the largest robotic telescope in the world. This, in conjunc…
A catalog of spectroscopic binary candidate stars derived from a comparison of Gaia DR2 with other radial velocity catalogs
Jack, Dennis
Using the recently published Gaia second data release that includes measurements of the mean radial velocity of about 7.2 million stars, we performed a systematic comparison with other existing radial velocity catalogs to search for variations in the radial velocity measurements, with the goal that detected differences may indicate that these star…
Analytical Resolution of the Dark Night Sky (Olbers') Paradox
Harari, Zaki
We derive a spatiotemporal analytical resolution of the dark night sky, or Olbers' paradox, first showing that in an infinitely large universe the cumulative solid angle of the light that is projected upon the celestial sphere by an infinite population of directly observable stars is indeed finite. Using the GAIA DR2 data, we show that the number …
Project BMK10k: Zeiss Ballistische Messkammer with a 10k × 10k CCD for ground‑based PLATO support
Chini, Rolf; Strassmeier, Klaus G.; Granzer, Thomas +5 more
Ballistische Messkammer with 10k CCD's (BMK10k) central goal is supporting the upcoming PLAnetary Transits and Oscillation of stars (PLATO) mission by reducing its number of false positives (planet‑compatible transit candidates but not planets at the end). For Kepler, the number of false positives had been estimated to still be about 10%. Understa…