Authors: B. Parise, S. Leurini, P. Schilke, E. Roueff, S. Thorwirth and D. C. Lis
A&A 508, 737 (2009) Received 26 June 2009 / Accepted 18 September 2009
Keywords: astrochemistry, line: identification, line: formation, ISM: abundances, ISM: individual objects: Orion Bar, ISM: molecules

Authors: N. Gai, S. L. Bi, Y. K. Tang and L. H. Li
A&A 508, 849 (2009) Received 3 May 2009 / Accepted 18 September 2009
Keywords: stars: evolution, stars: interiors, stars: oscillations

Authors: S. De Grandi and S. Molendi
A&A 508, 565 (2009) Received 22 June 2009 / Accepted 27 August 2009
Keywords: X-rays: galaxies: clusters, galaxies: clusters: general, supernovae: general, galaxies: abundances, cooling flows, intergalactic medium

Authors: D. Barrado, M. Morales-Calderón, A. Palau, A. Bayo, I. de Gregorio-Monsalvo, C. Eiroa, N. Huélamo, H. Bouy, O. Morata and L. Schmidtobreick
A&A 508, 859 (2009) Received 4 April 2009 / Accepted 22 September 2009
Keywords: circumstellar matter, stars: formation, stars: low-mass, brown dwarfs, stars: pre-main sequence, infrared: stars

Authors: J. Rodriguez, J. A. Tomsick, A. Bodaghee, J.-A. Zurita Heras, S. Chaty, A. Paizis and S. Corbel
A&A 508, 889 (2009) Received 22 June 2009 / Accepted 9 October 2009
Keywords: X-rays: binaries, accretion, accretion disks, stars: individual: IGR J19294+1816, stars: individual: IGR J11215-5952, stars: individual: IGR J18483-0311

Authors: N. Bello González, M. Flores Soriano, F. Kneer and O. Okunev
A&A 508, 941 (2009) Received 4 April 2009 / Accepted 10 August 2009
Keywords: Sun: photosphere, Sun: chromosphere, Sun: oscillations, techniques: high angular resolution, techniques: spectroscopic

Authors: F. D. Barazza, C. Wolf, M. E. Gray, S. Jogee, M. Balogh, D. H. McIntosh, D. Bacon, M. Barden, E. F. Bell, A. Böhm, J. A. R. Caldwell, B. Häussler, A. Heiderman, C. Heymans, K. Jahnke, E. van Kampen, K. Lane, I. Marinova, K. Meisenheimer, C. Y. Peng, S. F. Sanchez, A. Taylor, L. Wisotzki and X. Zheng
A&A 508, 665 (2009) Received 18 June 2009 / Accepted 16 October 2009
Keywords: galaxies: dwarf, galaxies: formation, galaxies: evolution, galaxies: clusters: individual: Abell 901/902, galaxies: structure

Authors: M. Rabus, H. J. Deeg, R. Alonso, J. A. Belmonte and J. M. Almenara
A&A 508, 1011 (2009) Received 1 April 2009 / Accepted 28 August 2009
Keywords: planetary systems, methods: N-body simulations, techniques: photometric

Authors: Haili Hu, G. Nelemans, C. Aerts and M.-A. Dupret
A&A 508, 869 (2009) Received 15 June 2009 / Accepted 1 October 2009
Keywords: subdwarfs, stars: evolution, stars: oscillations, methods: numerical

Authors: D. Santos-Costa, S. J. Bolton and R. J. Sault
A&A 508, 1001 (2009) Received 18 March 2009 / Accepted 21 August 2009
Keywords: radiation mechanisms: non-thermal, solar system: general, radio continuum: solar system

Authors: M. Ammler-von Eiff and E. W. Guenther
A&A 508, 677 (2009) Received 18 June 2009 / Accepted 2 September 2009
Keywords: stars: abundances, stars: fundamental parameters, open clusters and associations: individual: Ursa Major group, solar neighborhood

Authors: A. R. López-Sánchez and C. Esteban
A&A 508, 615 (2009) Received 12 March 2009 / Accepted 25 September 2009
Keywords: stars: Wolf-Rayet, galaxies: abundances, galaxies: starburst, galaxies: interactions, galaxies: dwarf, galaxies: kinematics and dynamics

Authors: M. Galametz, S. Madden, F. Galliano, S. Hony, F. Schuller, A. Beelen, G. Bendo, M. Sauvage, A. Lundgren and N. Billot
A&A 508, 645 (2009) Received 23 July 2009 / Accepted 28 September 2009
Keywords: galaxies: ISM, galaxies: dwarf, infrared: ISM, dust, extinction

Author: L. Belluzzi
A&A 508, 933 (2009) Received 21 July 2009 / Accepted 6 August 2009
Keywords: atomic processes, polarization, scattering, Sun: atmosphere

Authors: S. Kraus, K.-H. Hofmann, F. Malbet, A. Meilland, A. Natta, D. Schertl, P. Stee and G. Weigelt
A&A 508, 787 (2009) Received 26 July 2009 / Accepted 28 October 2009
Keywords: stars: pre-main-sequence, circumstellar matter, accretion, accretion disks, planetary systems: protoplanetary disks, planetary systems: formation, techniques: interferometric

The Chinese government is investing in
a rocket engine called the Emdrive that generates thrust
with microwaves.  There appears to be a slight problem,
however, with this engine: it violates conservation of
momentum.

Objects supported by electron degeneracy pressure
span a broad range of masses.  The low-mass end of this
range, which is near the mass of Saturn, is set by the
transition from pressure exerted by atoms to pressure
exerted by degenerate electrons.  The high end of this range,
which is 1.4 solar masses, is set by the gravitational
instability that arises when the degenerate electrons have
kinetic energies equal to the electron rest-mass energy.
These limits are given by several fundamental constants
of physics.  Despite the neutron stars being supported
by neutron and proton degeneracy pressure rather than
electron degeneracy pressure, they have an upper mass
similar to that of the degenerate dwarf.

Jupiter and Saturn have a fundamental link
to the degenerate (white) dwarfs and neutron stars: all
of these objects are supported against gravitational
collapse by a pressure generated through the Pauli
exclusion principle of quantum mechanics.  This pressure
is called degeneracy pressure, and it acts through electrons
in planets, brown dwarfs, and degenerate dwarfs, and through
neutrons and protons in neutron stars.  It's existence is
directly linked to existence of chemical elements with
distinctive properties. 

Degeneracy pressure—the pressure caused by the Pauli
exclusion principle of quantum mechanics—is manifested by
four types of astronomical object: the giant gaseous planet,
the brown dwarf, the degenerate dwarf, and the neutron star.
The first-three objects constitute the subclass of degenerate
objects that are supported by electron degeneracy pressure.
The neutron star is the subclass of degenerate objects supported
by neutron and proton degeneracy pressure.  The degenerate
dwarf and the neutron star are two of the three endpoints
of stellar evolution (the third endpoint is the black hole).
Binary star systems containing a degenerate object are the
most brilliant systems in the Galaxy.

The radii of degenerate dwarfs and of neutron stars
are fundamentally linked to the fundamental constants
of physics.  The neutron star is about the size of
a black hole of comparable mass.  The degenerate dwarf,
on the other hand, has a radius that is of order 2,000 times
larger.  This difference in radius is a direct consequence
of the proton being more massive than the electron by this
factor.  The mass of the proton sets the absolute scale
for these objects.  The radius of the neutron star is of
order 15 km, and the radius of the degenerate dwarf
is comparable to Earth's.