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The PL calibration for Milky Way Cepheids and its implications for the distance scale
Turner, David G.
The rationale behind recent calibrations of the Cepheid PL relation using the Wesenheit formulation is reviewed and reanalyzed, and it is shown that recent conclusions regarding a possible change in slope of the PL relation for short-period and long-period Cepheids are tied to a pathological distribution of HST calibrators within the instability s…
Supernova remnants, planetary nebulae and the distance to NGC 4214
Mutchler, Max; Windhorst, Rogier; Blair, William P. +23 more
We present narrow band, continuum subtracted Hα, [S II], Hβ, [O III] and [O II] data taken with the Wide Field Camera 3 on the Hubble Space Telescope in the nearby dwarf starburst galaxy NGC 4214. From these images, we identify seventeen new planetary nebula candidates, and seven supernova remnant candidates. We use the observed emission line lumi…
CoRoT 102931335: a candidate γ Dor in an eclipsing binary
Cardini, D.; Ribas, I.; Balaguer-Núñez, L. +3 more
We present an on-going study of CoRoT 102931335. Our preliminary results indicate that the target is an eclipsing binary system with an orbital period of
Dark mammoth trunks in the merging galaxy NGC 1316 and a mechanism of cosmic double helices
Carlqvist, Per
NGC 1316 is a giant, elliptical galaxy containing a complex network of dark, dust features. The morphology of these features has been examined in some detail using a Hubble Space Telescope, Advanced Camera for Surveys image. It is found that most of the features are constituted of long filaments. There also exist a great number of dark structures …
EC 11481–2303—a peculiar subdwarf OB star revisited
Rauch, Thomas; Werner, Klaus; Kruk, Jeffrey W.
EC 11481–2303 is a peculiar, hot, high-gravity pre-white dwarf. Previous optical spectroscopy revealed that it is a sdOB star with Teff=41 790 K, log g=5.84, and He/H = 0.014 by number. We present an on-going spectral analysis by means of non-LTE model-atmosphere techniques based on high-resolution, high-S/N optical (VLT-UVES) and ultra…
Spectrophotometric variability of the magnetic CP star 56 Arietis in spectral region from 1950 to 3200 Å
Sokolov, Nikolay A.
The spectrophotometric variability of the magnetic CP star 56 Arietis (56 Ari) in the ultraviolet spectral region from 1950 to 3200 Å is investigated. This study is based on the archival International Ultraviolet Explorer data obtained at different phases of the rotational cycle. The brightness of 56 Ari is not constant in the investigated wavelen…
The red-giant CoRoT target HR 7349
Auvergne, M.; Eggenberger, P.; Baudin, F. +19 more
HR 7349 is a bright [V=5.8] red giant observed by CoRoT in the seismofield of the first long run. The outstanding CoRoT light curve allowed the detection of several solar-like oscillation modes (both radial and non-radial). On top of these seismic constraints, our observational knowledge on HR 7349 benefits as well from a precise parallax and deta…
CoRoT observations of the young open cluster Dolidze 25
Prada Moroni, P. G.; Degl'Innocenti, S.; Gandolfi, D. +27 more
We present some preliminary results based on the CoRoT observations of the young distant cluster Dolidze 25. The light curve for the 28 stars observed by the satellite have been analyzed and the relevant periodogram presented. As a result we have found two binary, three Pulsating Be, three SPB, two Spotted and one ellipsoidal variables. Noteworthy…
Spectral behavior of AM Her and QQ Vul in high and intermediate states in the UV
Sanad, M. R.
We present low resolution UV spectra of two polar systems, AM Her and QQ Vul from the observations taken by the IUE (International Ultraviolet Explorer) of the period between 1978–1996 and 1983–1996 for both systems respectively, to accomplish a large scale study of what happens to the ultraviolet flux of C IV 1550 Å spectral line during different…