Water Ice in 2060 Chiron and its Implications for Centaurs and Kuiper Belt Objects

We report the detection of water ice in the Centaur 2060 Chiron, based on near-infrared spectra (1.0 - 2.5 micron) taken with the 3.8-meter United Kingdom Infrared Telescope (UKIRT) and the 10-meter Keck Telescope. The appearance of this ice is correlated with the recent decline in Chiron's cometary activity: the decrease in the coma cross-section allows previously hidden solid-state surface features to be seen. We predict that water ice is ubiquitous among Centaurs and Kuiper Belt objects, but its surface coverage varies from object to object, and thus determines its detectability and the occurrence of cometary activity.Comment: 18 pages, 3 figures, accepted by ApJ Letter

Population of the Scattered Kuiper Belt

We present the discovery of three new Scattered Kuiper Belt Objects (SKBOs) from a wide-field survey of the ecliptic. This continuing survey has to date covered 20.2 square degrees to a limiting red magnitude of 23.6. We combine the data from this new survey with an existing survey conducted at the University of Hawaii 2.2m telescope to constrain the number and mass of the SKBOs. The SKBOs are characterized by large eccentricities, perihelia near 35 AU, and semi-major axes > 50 AU. Using a maximum-likelihood model, we estimate the total number of SKBOs larger than 100 km in diameter to be N = 3.1 (+1.9/-1.3) x 10^4 (1 sigma) and the total mass of SKBOs to be about 0.05 Earth masses, demonstrating that the SKBOs are similar in number and mass to the Kuiper Belt inside 50 AU.Comment: 15 pages, 3 figure

Towards a Centralized Venture Capital Data Source - The Key to Increased Minority Access to Venture Capital?

In 2016, Steven Kaplan and Josh Lerner wrote about how the shortage of reliable and comprehensive industry data has created challenges for academics who wish to replicate or build on previous venture capital1 (VC) studies (414). The author of this paper experienced a similar lack of data first-hand while attempting to validate findings from a 2008 study which found that minority focused VC funds tend to earn equivalent or higher returns on their investments than the returns of the VC industry (Bates and Bradford 2008). The data required was virtually nonexistent, which prompted a search for databases which collect VC data. This paper is a call to action for greater VC fund financial transparency. This paper’s original goal of validating a prior study should be replicable by any researcher. The findings, which result from first-hand experiences and secondary research sources, conclude that while there are various companies and resources that offer VC data, none can provide the necessary compilation of VC fund IRR data efficiently or inexpensively. This suggests that such a collection is needed

Population and Size Distribution of Small Jovian Trojan Asteroids

We present a study of Jovian Trojan objects detected serendipitously during the course of a sky survey conducted at the University of Hawaii 2.2-meter telescope. We used a 8192 x 8192 pixel charge-coupled device (CCD) mosaic to observe 20 deg^2 at locations spread over the L4 Lagrangian swarm and reached a limiting magnitude V = 22.5 mag (50% of maximum detection efficiency). Ninety-three Jovian Trojans were detected with radii 2 - 20 km (assumed albedo 0.04). Their differential magnitude distribution has a slope of 0.40 +/- 0.05 corresponding to a power law size distribution index 3.0 +/- 0.3 (1-sigma). The total number of L4 Trojans with radii > 1 km is of order 1.6 x 10^5 and their combined mass (dominated by the largest objects) is ~ 10^{-4} M_{Earth}. The bias-corrected mean inclination is 13.7 +/- 0.5 deg. We also discuss the size and spatial distribution of the L4 swarm.Comment: 21 pages, 11 figures. AJ, in pres

Large Bodies in the Kuiper Belt

We present a survey for bright Kuiper Belt Objects (KBOs) and Centaurs, conducted at the Kitt Peak National Observatory (KPNO) 0.9 m telescope with the KPNO 8k Mosaic CCD. The survey imaged 164 sq deg near opposition to a limiting red magnitude of 21.1. Three bright KBOs and one Centaur were found, the brightest KBO having red magnitude 19.7, about 700 km in diameter assuming a dark Centaur-like 4% albedo. We estimate the power-law differential size distribution of the Classical KBOs to have index q = 4.2 (+0.4)(-0.3), with the total number of Classical KBOs with diameters larger than 100 km equal to 4.7 (+1.6)(-1.0) x 10^4. Additionally, we find that if there is a maximum object size in the Kuiper Belt, it must be larger than 1000 km in diameter. By extending our model to larger size bodies, we estimate that 30 (+16)(-12) Charon-sized and 3.2 (+2.8)(-1.7) Pluto-sized Classical KBOs remain undiscovered.Comment: 33 pages, 7 figures, to appear in Nov 2001 Astronomical Journa

Properties of the Trans-Neptunian Belt: Statistics From the CFHT Survey

We present the results of a wide-field survey designed to measure the size, inclination, and radial distributions of Kuiper Belt Objects (KBOs). The survey found 86 KBOs in 73 square degrees observed to limiting red magnitude 23.7 using the Canada-France-Hawaii Telescope and the 12k x 8k CCD Mosaic camera. For the first time, both ecliptic and off-ecliptic fields were examined to more accurately constrain the inclination distribution of the KBOs. The survey data were processed using an automatic moving object detection algorithm, allowing a careful characterization of the biases involved. In this work, we quantify fundamental parameters of the Classical KBOs (CKBOs), the most numerous objects found in our sample, using the new data and a maximum likelihood simulation. Deriving results from our best-fit model, we find that the size distribution follows a differential power law with exponent q = 4.0 (+0.6)(-0.5) (1 sigma, or 68.27% confidence). In addition, the CKBOs inhabit a very thick disk consistent with a Gaussian distribution of inclinations with a Half-Width of i(1/2) = 20 (+6)(-4) deg (1 sigma). We estimate that there are N = 3.8 (+2.0)(-1.5) x 10^4 (1 sigma) CKBOs larger than 100 km in diameter. We also find compelling evidence for an outer edge to the CKBOs at heliocentric distance R = 50 AU.Comment: To be published in the Astronomical Journal, July 200

Isotope effect for associative detachment: H(D)−+H(D)→H2(D2)+e

We report experimental and theoretical results for associative detachment (AD) of D−+D→D2+e−. We compare these data to our previously published results for H−+H→H2+e−. The measurements show no significant isotope effect in the total cross section. This is to be contrasted with previously published experimental and theoretical work which has found a significant isotope effect in diatomic systems for partial AD cross sections, i.e., as a function of the rotational and vibrational levels of the final molecule formed. Our work implies that though the rovibrational distribution of flux is different for AD of H− + H and D− + D, the total flux for these two systems is essentially the same when summed over all possible final channels

High relative expression of two genes of a melon near-isogenic line versus its parental during ripening

[SPA] Con el fin de comparar la expresión génica de una línea casi isogénica (NIL) SC10-2 de melón y su Piel de Sapo (PS) parental durante la maduración y para comprender los mecanismos de diferenciación, se realizó una secuenciación de transcriptoma. Los genes CmTCP15 (Factor de actividad de transcripción) y CmGDSL (actividad de la esterasa y la lipasa) tenían una alta expresión diferencial en el NIL SC10-2 en comparación con el PS debido a la introgresión en LG X. En consecuencia, algunos atributos de calidad de fruto como el aroma, dulzura y, probablemente otros pueden estar afectados por tales genes. [ENG] In order to compare the gene expression of a melon Near-isogenic Line (NIL) SC10-2 and its parental Piel de Sapo (PS) during ripening and to understand the differentiate mechanisms, a transcriptome sequencing was performed. CmTCP15 (Transcription factor activity) and CmGDSL (Esterase and lipase activity) genes were high differentially expressed in the NIL SC10-2 compared with PS due to the introgression in LG X. Consequently, some fruit quality traits such as aroma, sweetness and probably others can be affected by such genes.Financial support: Fundación Séneca de la Región de Murcia (11784/PI/09), MINECO & UE-FEDER funds (AGL2010-20858). Thanks for the technical assistance to P. Varó and his team in CIFEA-Torre Pacheco (Consejería de Agricultura, Región de Murcia), N. Dos-Santos, E. Cuadros, M. García-Gutiérrez, A. Hakmaoui (UPCT), M.J. Roca (SAIT-UPCT), and IRTA-CRAG for the seeds of the NIL