The Citation Impact of Digital Preprint Archives for Solar Physics Papers

Papers that are posted to a digital preprint archive are typically cited twice as often as papers that are not posted. This has been demonstrated for papers published in a wide variety of journals, and in many different subfields of astronomy. Most astronomers now use the arXiv.org server (astro-ph) to distribute preprints, but the solar physics community has an independent archive hosted at Montana State University. For several samples of solar physics papers published in 2003, I quantify the boost in citation rates for preprints posted to each of these servers. I show that papers on the MSU archive typically have citation rates 1.7 times higher than the average of similar papers that are not posted as preprints, while those posted to astro-ph get 2.6 times the average. A comparable boost is found for papers published in conference proceedings, suggesting that the higher citation rates are not the result of self-selection of above-average papers.Comment: 5 pages, 1 table, Solar Physics accepte

A deeper understanding of white dwarf interiors

A detailed record of the physical processes that operate during post-main-sequence evolution is contained in the internal chemical structure of white dwarfs. Global pulsations allow us to probe the stellar interior through asteroseismology, revealing the signatures of prior nuclear burning, mixing, and diffusion in these stars. I review the rapid evolution of structural models for helium-atmosphere variable (DBV) white dwarfs over the past five years, and I present a new series of model-fits using recent observations to illustrate the relative importance of various interior structures. By incorporating physically motivated C/O profiles into double-layered envelope models for the first time, I finally identify an optimal asteroseismic model that agrees with both diffusion theory and the expected nuclear burning history of the progenitor. I discuss the implications of this fundamental result, and I evaluate the prospects for continued progress in the future.Comment: 5 pages, 2 figures, 1 table, Accepted for MNRAS Letter

The Consequences of assuming m=0 for Global Model-fitting

A recent re-analysis of Whole Earth Telescope observations of GD 358 obtained in 1990 suggests that asteroseismology of additional DBV white dwarfs can lead to independent constraints on the important, but poorly determined, ^{12}C(alpha,gamma)^{16}O nuclear reaction rate. Data exist for several other DBV white dwarfs, but relatively few modes are detected and there is often no multiplet structure to aid in the identification of the spherical harmonic indices (l,m). I use a new grid of one million DBV models covering a broad range of masses, temperatures, and surface helium layer masses to investigate the consequences of assuming m=0 for global model-fitting. I find that when the spherical degree is known and the rotation period is of order 1 day, the model-fitting procedure applied to modes with unknown m-values will still correctly identify the_families_ of possible solutions, and has a high probability of identifying the same globally optimal solution found when the m-value is known.Comment: 5 pages, 2 figures, to appear in proceedings of the 6th Whole Earth Telescope worksho

Crowdfunding Astronomy Research with Google Sky

For nearly four years, NASA's Kepler space telescope searched for planets like Earth around more than 150,000 stars similar to the Sun. In 2008 with in-kind support from several technology companies, our non-profit organization established the Pale Blue Dot Project, an adopt-a-star program that supports scientific research on the stars observed by the Kepler mission. To help other astronomy educators conduct successful fundraising efforts, I describe how this innovative crowdfunding program successfully engaged the public over the past seven years to help support an international team in an era of economic austerity.Comment: 7 pages, 3 figures, Journal of Astronomy & Earth Sciences Education, accepted. Project website is at http://adoptastar.whitedwarf.or

WhiteDwarf.org - Establishing a permanent endowment for the Whole Earth Telescope

White Dwarf Research Corporation is a 501(c)(3) non-profit organization dedicated to scientific research and public education on topics relevant to white dwarf stars. It was founded in 1999 in Austin, Texas to help fulfill the need for an alternative research center where scarce funding dollars could be used more efficiently, and to provide a direct link between astronomers who study white dwarf stars and the general public. Due to its administrative simplicity, WDRC can facilitate the funding of multi-institutional and international collaborations, provide seamless grant portability, minimize overhead rates, and actively seek non-governmental funding sources. I describe the motivation for, and current status of, one of the long-term goals of WDRC: to establish a permanent endowment for the operation of the Whole Earth Telescope. I pay particular attention to fund-raising efforts through the website at http://WhiteDwarf.org/donate/Comment: 5 pages, to appear in proceedings of the 6th Whole Earth Telescope worksho