### Jay Cross

Shared publicly -**Astronomy Papers That Caught Fred's Eye In Today's arXiv**

These are the Friday papers.

"Eye-catching" papers submitted to astro-archives today (Friday).

Topics selected include

* A minimal width of the arrival direction distribution of ultra-high energy cosmic rays detected with the Yakutsk array* http://arxiv.org/abs/1502.07496 This paper supports recent announcements that cosmic rays arrive from fairly compact source 'areas'; but on the narrowest of scales, we are still a ways from pinning them down.

All well and good, but wouldn't this exact cancelation be manifest by any similarly contrived pairs of phenomena, and wouldn't there be the same results if their were no off-setting effects at all? (There is a similar cancelation of General Relativistic mass effects between polar and equatorial masses.)

Topics selected include

**Dark Matter, The James Webb Telescope, Cosmic Ray origins, Planetary Rings, VLBI, Crowdfunding****Milking the spherical cow: on aspherical dynamics in spherical coordinates**http://arxiv.org/abs/1502.07356 We have had some fun with 'round cow' assumptions on this thread; this paper looks at the differences between 'real dark matter' and 'round cow' approximations.**James Webb Space Telescope can Detect Kilonovae in Gravitational Wave Follow-up Search**http://arxiv.org/abs/1502.07426 What surprised me the most about this paper is that the launch date for the James Webb Space Telescope has been pushed out to at least 2018; and the Advanced Ligo Gravitational Wave telescope is not expected to be operating at optimum sensitivity until 2019.* A minimal width of the arrival direction distribution of ultra-high energy cosmic rays detected with the Yakutsk array* http://arxiv.org/abs/1502.07496 This paper supports recent announcements that cosmic rays arrive from fairly compact source 'areas'; but on the narrowest of scales, we are still a ways from pinning them down.

**Why are dense planetary rings only found between 8 AU and 20 AU?**http://arxiv.org/abs/1502.07696 This seemingly obvious question has an equally obvious answer, but has anyone really ask it; or answered it before?**The deflection of light induced by the Sun's gravitational field and measured with geodetic VLBI**http://arxiv.org/abs/1502.07395 The authors claim an explicit proof of General Relativity using VLBI data; but one aspect of the proof is very troubling to me. From the authors: "In addition, the coordinate term explicitly presented in the conventional geometric delay model ceases to exist because it is compensated by the same effect in the gravitational delay with the opposite sign."All well and good, but wouldn't this exact cancelation be manifest by any similarly contrived pairs of phenomena, and wouldn't there be the same results if their were no off-setting effects at all? (There is a similar cancelation of General Relativistic mass effects between polar and equatorial masses.)

**Crowdfunding Astronomy with Google Sky**http://arxiv.org/abs/1502.07393Abstract: Galaxies and the dark matter halos that host them are not spherically symmetric, yet spherical symmetry is a helpful simplifying approximation for idealised calculations and analysis of observational data. The assumption leads to an exact conservation of angular momentum for every ...

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