Report on Astronomical Constants

Report on Astronomical Constants

Recent progress in the determinations of astronomical constants is reviewed. First is the latest estimation of the general relativistic scale constants, LC , LG, and LB (Irwin and Fukushima, 1999). By reestimating the uncertainty, the value of the rst constant is given as LC = 1:480 826 867 4 10 8 1:4 10 . Also noted is the rigorous relation among these three, LB = LC +LG LCLG. Based on the lat...

Use of astronomical literature - A report on usage patterns

In this paper we present a number of metrics for usage of the SAO/NASA Astrophysics Data System (ADS). Since the ADS is used by the entire astronomical community, these are indicative of how the astronomical literature is used. We will show how the use of the ADS has changed both quantitatively and qualitatively. We will also show that different types of users access the system in different way...

Infrared spectra and optical constants of astronomical ices: II. Ethane and ethylene

Infrared spectroscopic observations have established the presence of hydrocarbon ices on Pluto and other TNOs, but the abundances of such molecules cannot be deduced without accurate optical constants (n, k) and reference spectra. In this paper we present our recent measurements of nearand mid-infrared optical constants for ethane (C2H6) and ethylene (C2H4) in multiple ice phases and at multipl...

Infrared spectra and optical constants of astronomical ices: I. Amorphous and crystalline acetylene

Multiplication by rational constants LIP research report

Multiplications by simple rational constants often appear in fixed-point or floating-point application code, for instance in the form of division by an integer constant. The hardware implementation of such operations is of practical interest to FPGA-accelerated computing. It is well known that the binary representation of rational constants is eventually periodic. This article shows how this fe...