Ultra diffuse galaxies (UDGs) have the sizes of giants but the luminosities of dwarfs. A key to understanding their origins comes from their total masses, but...
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NewsThe dark side of the fluffiest galaxies
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NewsThe distribucion of electron densiy in the HII regions of the galaxies M51 and NGC 4449
Using images of the Advanced Camera for Surveys" of the Hubble SpaceTelescope we have analyzed the global physical parameters of thepopulations of HII regions...
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NewsThe distribution of gas and star formation in M 81.
In this work we present the first complete CO J=3-2 map of M 81, observed as part of the Nearby Galaxies Legacy Survey. M 81 is a nearby spiral galaxy (3.64 Mpc...
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NewsThe double-degenerate, super-Chandrasekhar nucleus of the planetary nebula Henize 2–428.
The planetary nebula (PN) stage is the ultimate fate of stars with mass 1 to 8 solar masses (M⊙). The origin of their complex morphologies is poorly understood...
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NewsThe early sequence of events that shaped the Milky Way
Among the myriad discoveries presented in the second data release of the Gaia mission, there was an enigmatic color-magnitude diagram (CMD) of Milky Way halo...
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NewsThe effect of magnetic fields on solar abundance determinations.
In a recently published differential analysis (see ApJ, 724, 1536, Dec. 1 issue) , we have derived abundance corrections for iron lines, using synthetic spectra...
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NewsThe excitation of solar-like oscillations in a delta Scuti star by efficient envelope convection.
Delta Scuti (δ Sct) stars are opacity-driven pulsators with masses of 1.5-2.5M⊙, their pulsations resulting from the varying ionization of helium. In less...
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NewsThe extreme CNO-enhanced composition of a primitive iron-poor dwarf star
We present an analysis of high-resolution Keck/HIRES spectroscopic observations of J0815+4729, an extremely carbon-enhanced, iron-poor dwarf star. These high...
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NewsThe Fast Spiral-in of the companion star to the black hole XTE J1118+480.
We report the detection of an orbital period decay of (dP/dt)= -1.83+-0.66 ms yr–1 in the black hole X-ray binary XTE J1118+480. This corresponds to a period...