Variable stars with the Kepler space telescope

The Kepler space telescope has revolutionised our knowledge about exoplanets and stars and is continuing to do so in the K2 mission. The exquisite photometric precision, together with the long, uninterrupted observations opened up a new way to investigate the structure and evolution of stars. Asteroseismology, the study of stellar oscillations, allowed us to investigate solar-like stars and to peer into the insides of red giants and massive stars. But many discoveries have been made about classical variable stars too, ranging from pulsators like Cepheids and RR Lyraes to eclipsing binary stars and cataclysmic variables, and even supernovae. In this review, which is far from an exhaustive summary of all results obtained with Kepler, we collected some of the most interesting discoveries, and ponder on the role for amateur observers in this golden era of stellar astrophysics.Comment: 12 pages, 6 figures, published in the Journal of the AAVSO: https://www.aavso.org/apps/jaavso/article/3235/, v2: fixed a bad a reference. arXiv admin note: text overlap with arXiv:1108.3083 by other author

Shockwave Behaviour in RR Lyrae Stars

Here we present the detailed analysis of some modulated Kepler and K2 RR Lyrae stars that show peculiar bump progression in respect to the pulsation phase.Comment: 3 pages, 3 figures, to be published in the proceedings of "The RR Lyrae 2017 Conference", Niepolomice, Poland, 17-21 September 201

RR Lyrae stars as seen by the Kepler space telescope

The unprecedented photometric precision along with the quasi-continuous sampling provided by the Kepler space telescope revealed new and unpredicted phenomena that reformed and invigorated RR Lyrae star research. The discovery of period doubling and the wealth of low-amplitude modes enlightened the complexity of the pulsation behavior and guided us towards nonlinear and nonradial studies. Searching and providing theoretical explanation for these newly found phenomena became a central question, as well as understanding their connection to the oldest enigma of RR Lyrae stars, the Blazhko effect. We attempt to summarize the highest impact RR Lyrae results based on or inspired by the data of the Kepler space telescope both from the nominal and the K2 missions. Besides the three most intriguing topics, the period doubling, the low-amplitude modes, and the Blazhko effect, we also discuss the challenges of Kepler photometry that played a crucial role in the results. The secrets of these amazing variables, uncovered by Kepler, keep the theoretical, ground-based and space-based research inspired in the post-Kepler era, since light variation of RR Lyrae stars is still not completely understood.Comment: 25 pages, 9 figures, review article, accepted in Frontiers in Astronomy and Space Science

A lupus nephritis kezelésének irányelvei, valamint a mycofenolat mofetil hatékonyságának bemutatása intézetünk lupus nephritises betegeinek körében | Clinical guideline for the treatment of lupus nephritis and single-centre results of mycofenolate mofetil among patients with lupus nephritis in the National Institute of Rheumatology and Physiotherapy, Budapest

Absztrakt A szerzők közleményükben a lupus nephritis kezelésének legújabb irányelvei mellett bemutatják saját mycofenolat mofetillel szerzett tapasztalataikat a betegség kezelésében. A lupus nephritis és főleg a proliferatív formája olyan gyakori és komoly manifesztációja a szisztémás lupus erythematosusnak, amely végstádiumú veseelégtelenséghez vagy akár halálhoz is vezethet. Az elmúlt évtizedekben a lupus nephritis kezelése sokat fejlődött, ma már a kedvezőbb mellékhatás-profilú mycofenolat mofetil a cyclophosphamid alternatívájává vált a III-as és IV-es osztályú glomerulonephritis indukciós és fenntartó kezelésében. Lupus nephritis diagnózissal eddig 25 betegüknek kértek egyedi méltányosság alapján támogatást mycofenolat mofetil adására. Szövettanilag legtöbben a WHO III (A/C) és IV (A) szövettani osztályába tartoztak (30-30%), beszűkült vesefunkció csak 16%-ukban volt jelen. Glükokortikoid és cyclophosphamid indukciós kezelés után adott mycofenolatterápia mellett az átlagos napi proteinuria 3,18 g/napról 1,06 g/napra csökkent. A betegek 24%-ánál jött létre komplett, 48%-ánál részleges remisszió. Ezek alapján a mycofenolat mofetil hatékony kezelésnek tartható a proliferatív lupus nephritis kezelésében. Orv. Hetil., 2016, 157(35), 1385–1393. | Abstract The authors present the latest guideline for the treatment of lupus nephritis and their own single-centre results with mycofenolate mofetil treated lupus nephritis. Lupus nephritis and mainly its proliferative form is a frequent and potentially life-threatening manifestation of systemic lupus erythematosus that can lead to end-stage renal disease. The treatment of lupus nephritis greatly improved in the last decades; mycofenolate mofetil has become an alternative of cyclophosphamide both in remission induction and as a maintenance regimen as well in the treatment of Class III and IV glomerulonephritis. The authors ordered mycofenolate mofetil for 25 patients with lupus nephritis so far. Histologically most of them had Class III (A/C) or IV (A) glomerulonephritis (30–30%), and only 16% of the patients had renal impairment at that time. Mycofenolate mofetil given after glucocorticoid and cyclophosphamide induction therapy reduced the daily proteinuria from 3.18 grs to 1.06 grs. Complete remission could be achieved in 24% and partial remission in 48% of the patients. The authors conclude that mycofenolate mofetil is effective in the therapy of lupus nephritis. Orv. Hetil., 2016, 157(35), 1385–1393

Stress tolerance in auxin heterotrophic and autotrophic tobacco tissue cultures

The natures of the stress tolerance of auxin autotrophic and heterotrophic tobacco calli were compared. SO mM NaCI did not inhibit the growth of auxin autotrophic calli and they exhibited a lower level of peroxidase secretion into the media than that of heterotrophic cultures. The ascorbate peroxidase and catalase activities of these lines did not decrease in the presence of stressors. In the second half of the culturing period, the auxin autotrophic tissues expressed a higher GST activity than that of the heterotrophic lines

Automated Extended Aperture Photometry for K2 RR Lyrae stars

Light curves for RR Lyrae stars can be difficult to obtain properly in the K2 mission due to the similarities between the timescales of the observed physical phenomena and the instrumental signals appearing in the data. We developed a new photometric method called Extended Aperture Photometry (EAP), a key element of which is to extend the aperture to an optimal size to compensate for the motion of the telescope and to collect all available flux from the star before applying further corrections. We determined the extended apertures for individual stars by hand so far. Now we managed to automate the pipeline that we intend to use for the nearly four thousand RR Lyrae targets observed in the K2 mission. We present the outline of our pipeline and make some comparisons to other photometric solutions.Comment: To appear in Astronomical Society of the Pacific Conference Series, Volume 529, "RRLyrae/Cepheid2019: Frontiers of Classical Pulsators: Theory and Observations", Cloudcroft, NM, USA October 13-18, 201