Search Publications
XMM-Newton study of the Sculptor dwarf spheroidal galaxy
Sasaki, Manami; Saeedi, Sara
We analysed observations with XMM-Newton in the field of the Sculptor dwarf spheroidal galaxy (dSph). The aim of the study was the classification of X-ray binaries and accreting white dwarfs belonging to the Sculptor dSph. Using different methods of X-ray timing and spectral analyses, together with an extensive multiwavelength study of the optical…
Likely optical counterpart of the cool middle-aged pulsar J1957+5033
Geier, S.; Zharikov, S. V.; Karpova, A. V. +6 more
The 840-kyr-old pulsar PSR J1957+5033, detected so far only in γ- and X-rays, is a nearby and rather cool neutron star with a temperature of 0.2-0.3 MK, a distance of $\lesssim 1$kpc, and a small colour reddening excess E(B - V) ≈ 0.03. These properties make it an ideal candidate to detect in the optical to get additional constraints on its parame…
Young Exoplanet Transit Initiative follow-up observations of the T Tauri star CVSO 30 with transit-like dips
Neuhäuser, R.; Chen, W. P.; Mugrauer, M. +13 more
The T Tauri star CVSO 30, also known as PTFO 8-8695, was studied intensively with ground-based telescopes as well as with satellites over the last decade. It showed a variable light curve with additional repeating planetary transit-like dips every ~10.8 h. However, these dimming events changed in depth and duration since their discovery and from a…
Mid-infrared time-domain study of recent dust production events in the extreme debris disc of TYC 4209-1322-1
Pál, András; Rieke, George H.; Moór, Attila +24 more
Extreme debris discs are characterized by unusually strong mid-infrared excess emission, which often proves to be variable. The warm dust in these discs is of transient nature and is likely related to a recent giant collision occurring close to the star in the terrestrial region. Here we present the results of a 877 d long, gap-free photometric mo…
How the spectral energy distribution and galaxy morphology constrain each other, with application to morphological selection using galaxy colours
Kaviraj, Sugata; Uzeirbegovic, Emir; Martin, Garreth
We introduce an empirical methodology to study how the spectral energy distribution (SED) and galaxy morphology constrain each other and implement this on ~8000 galaxies from the HST CANDELS survey in the GOODS-South field. We show that the SED does constrain morphology and present a method that quantifies the strength of the link between these tw…
Discovery of an optical cocoon tail behind the runaway HD 185806
Meyer, D. M. -A.; Boumis, P.; Gvaramadze, V. V. +6 more
Studies on the circumstellar structures around evolved stars provide vital information on the evolution of the parent star and the properties of the local interstellar medium. In this work, we present the discovery and characterization of an optical cocoon tail behind the star HD 185806. The cocoon apex emission is puzzling, as it is detected in t…
Hot white dwarf candidates from the IGAPS-GALEX cross-match
Raddi, R.; Sabin, L.; Gómez-Muñoz, M. A. +1 more
White dwarf (WD) stars are often associated with the central stars of planetary nebulae (CSPNe) on their way to the cooling track. A large number of WD star candidates have been identified; thanks to optical large-scale surveys such as Gaia DR2 and EDR3. However, hot-WD/CSPNe stars are quite elusive in optical bands due to their high temperatures …
New, late-type spectroscopic binaries with X-ray emission
Guillout, P.; Giarrusso, M.; Leone, F. +6 more
In this paper, we present a spectroscopic study of six double-lined binaries, five of which were recently discovered in a high-resolution spectroscopic survey of optical counterparts of stellar X-ray sources. Thanks to high-resolution spectra acquired with CAOS spectropolarimeter during 7 yr, we were able to measure the radial velocities of their …
A detailed study of the barium central star of the planetary nebula Abell 70
Munday, James; Jones, David; Miszalski, Brent +4 more
We present a detailed study of the barium star at the heart of the planetary nebula Abell 70. Time-series photometry obtained over a period of more than 10 yr demonstrates that the barium-contaminated companion is a rapid rotator with temporal variability due to spots. The amplitude and phasing of the photometric variability change abruptly; howev…
The double-lined spectroscopic binary orbit of the massive supergiant HD 152147: A new target for interferometry
Gamen, R.; Barbá, R. H.; Morrell, N. I. +4 more
We present a new spectroscopic orbit of the O-type binary system HD 152147. We identify absorption lines in both components and use their radial velocities to determine the orbit, which results in a period of P = 50.2199 ± 0.0007 d, an eccentricity e = 0.738 ± 0.007, and a mean separation between the components of asin i = 151 ± 1 R⊙. C…