![]() Such a comparison yields a mass of ∼5 Jupiter masses for the fainter companion, a mass value placing the object firmly within the range of planets. The observed brightness, colors, and spectral information can be compared to theoretical models for young planets. But is it a planet? This is the tricky part to decide. First low-resolution spectra of the companion were also obtained. At the distance to the brown dwarf, this transforms to a projected separation of 55 AU. The fainter (and thus presumably much less massive) companion was detected 0.8 arcsec away from the brown dwarf ( Fig. This region contains young stars that are estimated to be only 8 million years old. Its location also gives away its age: The brown dwarf lies within a young star-forming region, the so-called TW Hydrae association. The central object (called 2MASSWJ 1207334-393254) has only ∼25 times the mass of Jupiter and is located at a distance of approximately 230 lightyears. One candidate was found near a young “failed” star, a brown dwarf, which itself is not massive enough to start thermonuclear reactions in its core. Computer controlled diamond machining has created even thinner cores (less than 1 mm in thickness) but the process requires longer generation times. Water jets could machine core walls that could be held to a thickness of around 1.5 mm over a core depth of 20 cm. ![]() In addition, the water jet cutting provided the ability to create very flexible geometries optimized to minimize weight while retaining stiffness. High-pressure water jets were developed that allowed cores to be made much faster than with diamond tooling. Diamond tooling was developed along with computer controlled systems to machine cores from solid blanks. New advances were also made in core manufacturing. The thicknesses of face-plates were typically reduced to around 7 mm and areal densities in the 40–50 kg m −2 range became routine. This allowed the cross-sections of the glass elements to be significantly reduced. Unlike the fusion process, Frit allowed the bonding of glass elements at a lower temperature. ![]() Photography courtesy of NASA.ĭuring the 1980s, Frit bonding technology was developed. 2.4 m ULE™ mirror made by Corning/Perkin Elmer for the Hubble Space Telescope.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |