Ca II H and K Spectroscopy of ER Vul

Regulation of CA II and H+,K(+)-ATPase gene expression in canine gastric parietal cells.

Acid secretagogue-specific receptor activation in parietal cells triggers rapid and coordinate gene expression of gastric H+,K(+)-ATPase and of CA II. The rapid rise in steady-state levels of CA II mRNA is due to new transcription of the CA II gene in stimulated cells. Although the presumed function of CA II in activated parietal cells is to catalyze the generation of HCO3- from OH-, regulation...

Dust depletion , chemical uniformity and environment of Ca ii H & K quasar absorbers

Ca ii λλ3934, 3969 absorbers, which are likely to be a subset of damped Lyman α systems, are the most dusty quasar absorbers known, with an order of magnitude more extinction in E(B−V) than other absorption systems. There is also evidence that Ca ii absorbers trace galaxies with more ongoing star-formation than the average quasar absorber. Despite this, relatively little is known in detail abou...

Modulation of Ca II H & K Emission by Short - Period Planets

We have detected modulation of the Ca II H&K reversal structure in four out of five 51 Peg-type stars whose planets have orbital periods between 3 and 4 days. We observe two effects in the K-core: (1) a broad 3-Å variation at ≈1% level and (2) changes on a scale of 0.5 Å (∼13%) in each of the three reversal features. The nightly variations are coherent in both H and K. From differential radial ...

Gemini Spectroscopy of the Ultra-compact Binary Candidate V407 Vul *

We present time-resolved spectroscopy of the optical counterpart to the proposed ultra-compact binary system V407 Vul (=RX J1914.4+2456). Our Gemini spectra resolve the 9.48 minute periodicity that has previously been reported for this source. We find that the optical counterpart is dominated by a reddened late-type spectrum of type G9V and contains solely unresolved absorption features. No rad...

VLT K - band spectroscopy of massive young stellar objects in ( ultra - ) compact H ii regions ⋆