Related papers: Moti e distanze angolari in cielo con telescopio e…
Several mission concepts are being studied to directly image planets around nearby stars. It is commonly thought that directly imaging a potentially habitable exoplanet around a Sun-like star requires space telescopes with apertures of at…
We use the new reduction of the Hipparcos data (van Leeuwen 2007) and a self-consistent distance determination technique for Lutz-Kelker limited samples to obtain distances to the massive stars in the solar vicinity. The distance…
The modern usage of the words astronomy and astrology is traced back to distinctions, largely ignored in recent scholarship. Three interpretations of celestial phenomena (in a geometric, a substantialist and a prognostic versions) coexisted…
Time-series transit photometry from the Kepler space telescope has allowed for the discovery of thousands of exoplanets. We explore the potential of yet improved future missions such as PLATO 2.0 in detecting solar system analogues. We use…
An emerging theme in modern astrophysics is the connection between astronomical observations and the underlying physical phenomena that drive our cosmos. Both the mechanisms responsible for the observed astrophysical phenomena and the tools…
We are conducting a spectroscopic monitoring of O and WN -type stars in our Galaxy. In this work, we summarize some of our first results related to the search for radial-velocity variations indicative of orbital motion.
We present a new analysis of the Jupiter+Saturn analog system, OGLE-2006-BLG-109Lb,c, which was the first double planet system discovered with the gravitational microlensing method. This is the only multi-planet system discovered by any…
In the 70s of the last century, the stratospheric solar observatory "Saturn" with a 100cm telescope was launched at Pulkovo Observatory. The photographs and spectra obtained on it for more than 45 years remained record-breaking in angular…
In May 2008, the Antares neutrino telescope was completed at 2.5 km depth in the Mediterranean Sea; data taking has been going on since. A prerequisite for neutrino astronomy is an accurate reconstruction of the neutrino events, as well as…
We summarize some of the compelling new scientific opportunities for understanding stars and stellar systems that can be enabled by sub-milliarcsec (sub-mas) angular resolution, UV-Optical spectral imaging observations, which can reveal the…
Large area surveys will dominate the forthcoming decades of astronomy and their success requires characterizing thousands of discoveries through additional observations at higher spatial or spectral resolution, and at complementary cadences…
The lifetime of a satellite is limited, and its calibration may be not stable, it is necessary to continue ground-based measures of the solar diameter with methods less affected by atmospheric turbulence, and optical aberrations: planetary…
An inert sphere of a few meters diameter, placed in a special stable geosynchronous orbit in perpetuo, can be used for a variety of scientific experiments. Ground-based observations of such a sphere, "GeoSphere", can resolve very difficult…
The angular momentum of a star is an important astrophysical quantity related to its internal structure, formation and evolution. On average, helioseismology yields S = 1.92 10^41 kg m^2 s^-1 for the angular momentum of the Sun. We show how…
The hope is that in the near future neutrino astronomy, born with the identification of thermonuclear fusion in the sun and the particle processes controlling the fate of a nearby supernova, will reach throughout and beyond our Galaxy and…
We report Venus image observations around the two maximum elongations of the planet at June and October 2015. From these images we describe the global atmospheric dynamics and cloud morphology in the planet before the arrival of JAXA…
This paper is to introduce an online tool for the prediction of exoplanet transit light curves. Small telescopes can readily capture exoplanet transits under good weather conditions when the combination of a bright star and a large…
An array of large observational programs using ground-based and space-borne telescopes is planned in the next decade. The forthcoming wide-field sky surveys are expected to deliver a sheer volume of data exceeding an exabyte. Processing the…
This paper on ASTROD I is based on our 2010 proposal submitted for the ESA call for class-M mission proposals, and is a sequel and an update to our previous paper [Experimental Astronomy 23 (2009) 491-527; designated as Paper I] which was…
If one wants to translate the heliocentric picture of planets moving uniformly on circular orbits about the sun to the perspective of a terrestrial observer, using classical (ancient) geometric means only, one is naturally led to the…