HIGH SPEED VIDEO IMAGING OF OVERHANG SURFACES IN BEAM SHAPED LASER POWDER BED FUSION OF 316L STAINLESS STEEL

Beam shaping has seen rising interest in the AM industry and research field because of the increased level of control over the spatial distribution of the thermal input during Laser Powder Bed Fusion, allowing for faster build rates. This report investigates if the more uniform heat input offers benefits to the scanning of unsupported overhanging structures. In-situ high speed video imaging is combined with post process surface characterization to derive a relation between the scan parameters and quality of the overhang surface. The best results were achieved at low energy densities, but no clear advantage of top-hat shaped laser spots over the standard Gaussian beams is observed.Mechanical Engineerin

XO-5b: A Transiting Jupiter-sized Planet With A Four Day Period

The star XO-5 (GSC 02959-00729, V=12.1, G8V) hosts a Jupiter-sized, Rp=1.15+/-0.12 Rjup, transiting extrasolar planet, XO-5b, with an orbital period of P=4.187732+/-0.00002 days. The planet mass (Mp=1.15+/-0.08 Mjup) and surface gravity (gp=22+/-5 m/s^2) are significantly larger than expected by empirical Mp-P and Mp-P-[Fe/H] relationships. However, the deviation from the Mp-P relationship for XO-5b is not large enough to suggest a distinct type of planet as is suggested for GJ 436b, HAT-P-2b, and XO-3b. By coincidence XO-5 overlies the extreme H I plume that emanates from the interacting galaxy pair NGC 2444/NGC 2445 (Arp 143).Comment: 10 pages, 9 Figures, Submitted to Ap

Discovery of a New Deeply Eclipsing SU UMa-Type Dwarf Nova, IY UMa (= TmzV85)

We discovered a new deeply eclipsing SU UMa-type dwarf nova, IY UMa, which experienced a superoutburst in 2000 January. Our monitoring revealed two distinct outbursts, which suggest a superoutburst interval of ~800 d, or its half, and an outburst amplitude of 5.4 mag. From time-series photometry during the superoutburst, we determined a superhump and orbital period of 0.07588 d and 0.0739132 d, respectively.Comment: 5 pages, 3 figures, accepted by PASJ lette

XO-3b: A Massive Planet in an Eccentric Orbit Transiting an F5V Star

We report the discovery of a massive (Mpsini = 13.02 +/- 0.64 Mjup; total mass 13.25 +/- 0.64 Mjup), large (1.95 +/- 0.16 Rjup) planet in a transiting, eccentric orbit (e = 0.260 +/- 0.017) around a 10th magnitude F5V star in the constellation Camelopardalis. We designate the planet XO-3b, and the star XO-3, also known as GSC 03727-01064. The orbital period of XO-3b is 3.1915426 +/- 0.00014 days. XO-3 lacks a trigonometric distance; we estimate its distance to be 260 +/- 23 pc. The radius of XO-3 is 2.13 +/- 0.21 Rsun, its mass is 1.41 +/- 0.08 Msun, its vsini = 18.54 +/- 0.17 km/s, and its metallicity is [Fe/H] = -0.177 +/- 0.027. This system is unusual for a number of reasons. XO-3b is one of the most massive planets discovered around any star for which the orbital period is less than 10 days. The mass is near the deuterium burning limit of 13 Mjup, which is a proposed boundary between planets and brown dwarfs. Although Burrows et al. (2001) propose that formation in a disk or formation in the interstellar medium in a manner similar to stars is a more logical way to differentiate planets and brown dwarfs, our current observations are not adequate to address this distinction. XO-3b is also unusual in that its eccentricity is large given its relatively short orbital period. Both the planetary radius and the inclination are functions of the spectroscopically determined stellar radius. Analysis of the transit light curve of XO-3b suggests that the spectroscopically derived parameters may be over estimated. Though relatively noisy, the light curves favor a smaller radius in order to better match the steepness of the ingress and egress. The light curve fits imply a planetary radius of 1.25 +/- 0.15 Rjup, which would correspond to a mass of 12.03 +/- 0.46 Mjup.Comment: 26 pages, 10 figures. Accepted by ApJ. Current version has several small corrections as a result of a bug in the fitting softwar

XO-2b: Transiting Hot Jupiter in a Metal-rich Common Proper Motion Binary

We report on a V=11.2 early K dwarf, XO-2 (GSC 03413-00005), that hosts a Rp=0.98+0.03/-0.01 Rjup, Mp=0.57+/-0.06 Mjup transiting extrasolar planet, XO-2b, with an orbital period of 2.615857+/-0.000005 days. XO-2 has high metallicity, [Fe/H]=0.45+/-0.02, high proper motion, mu_tot=157 mas/yr, and has a common proper motion stellar companion with 31" separation. The two stars are nearly identical twins, with very similar spectra and apparent magnitudes. Due to the high metallicity, these early K dwarf stars have a mass and radius close to solar, Ms=0.98+/-0.02 Msolar and Rs=0.97+0.02/-0.01 Rsolar. The high proper motion of XO-2 results from an eccentric orbit (Galactic pericenter, Rper<4 kpc) well confined to the Galactic disk (Zmax~100 pc). In addition, the phase space position of XO-2 is near the Hercules dynamical stream, which points to an origin of XO-2 in the metal-rich, inner Thin Disk and subsequent dynamical scattering into the solar neighborhood. We describe an efficient Markov Chain Monte Carlo algorithm for calculating the Bayesian posterior probability of the system parameters from a transit light curve.Comment: 14 pages, 10 Figures, Accepted in ApJ. Negligible changes to XO-2 system properties. Removed Chi^2 light curve analysis section, and simplified MCMC light curve analysis discussio