The Laboratory for Astronomy and Solar Physics ͑LASP͒ continues to conduct a broad program of research and instrument technology development in ultraviolet and infrared astronomy and in optical/UV, X-ray, gamma-ray, and visible-light studies of the Sun. The program encompasses theoretical, observational, and experimental work, using platforms in space such as the Hubble Space Telescope ͑HST͒ Space ...

We review a set of the possible ways to constrain extended gravity models at Galaxy clusters scales (the regime dark energy explanations and comparison with ΛCDM), for black hole shadows, gravitational wave astronomy, binary pulsars, Solar system Large Hadron Collider (consequences high-energy physics TeV scale). The key idea is that modern experimental observational precise data provide us cha...

In this essay, we immerse into the framework of normed division algebras as a suitable arena to accommodate standard model elementary particles, and explore some applications cosmology. Remarkably, they permit interesting non-trivial realisations cosmological principle with an interplay between symmetry groups quaternions octonions. We also argue how these give rise potentially observational si...

There has long been evidence that low-mass galaxies are systematically larger in radius, of lower central stellar mass density, and of lower central phase-space density, than are star clusters of the same luminosity. The larger radius, at a comparable value of central velocity dispersion, implies a larger mass at similar luminosity, and hence significant dark matter, in dwarf galaxies, compared...

National Astronomical Observatory is an inter-university institute serving as the national center for ground based astronomy offering observational facilities covering the optical, infrared, radio wavelength domain. NAOJ also has solar physics and geo-lunar science groups collaborating with JAXA for space missions and a theoretical group with computer simulation facilities. The outline of NAOJ,...

Using the known detection limits for high-resolution imaging observations and the statistical properties of true binary and line-of-sight companions, we estimate the binary fraction of Kepler exoplanet host stars. Our speckle imaging programs at the WIYN 3.5m and Gemini North 8.1-m telescopes have observed over 600 Kepler objects of interest (KOIs) and detected 49 stellar companions within ∼1 a...

We calculate how accurately parameters of the short-period binaries (10 Hz . f . 10 Hz) will be determined from the gravitational waves by LISA. In our analysis the chirp signal ḟ is newly included as a fitting parameters and dependence on observational period or wave frequency is studied in detail. Implications for gravitational wave astronomy are also discussed quantitatively. Subject heading...

The SKA's design is driven by the needs of cutting-edge radio astronomy for sensitivity and spacial resolution. However its design is also driven by the desire to explore the transient radio Universe. In addition to pulsars, the SKA will be able to carry out high time resolution observations of several classes of known and predicted transient sources. Here we consider a selection of them, and d...

We present an R-band lightcurve of an optical transient which is likely to be associated with the gamma-ray burst event GRB971214. Our first measurement took place 17 hours after the gamma-ray event. The brightness decayed with a power-law exponent α = −1.380 ± 0.013, which is significantly faster than the other two optically identified bursts, GRB970228 and GRB970508 which had exponents of α =...