Search Publications
Timing analysis of a sample of five cataclysmic variable candidates observed by the XMM-Newton satellite
Nucita, A. A.; De Paolis, F.; Franco, A. +4 more
Intermediate polars are a class of cataclysmic variables in which a white dwarf accretes material from a companion star. The intermediate polar nature confirmation usually derives from the detection of two periods in both X-ray and optical photometry. In this respect, the high-energy signal is often characterized by modulations on the white dwarf …
NGC 5236's stars as tracers of arms and arm widths in spiral galaxies
Silva-Villa, E.; Cano Gómez, X.
Generally, identifying the spiral arms of a spiral galaxy is not a hard task. However, defining the main characteristics, width, and length of those structure is not a common task. Previous studies have used different tracers: star clusters, massers, H α. It was until recently that individual stars were used as tracers of spiral structures. The ba…
Extragalactic transient candidates in the second Swift-XRT point source catalogue
O'Brien, P. T.; Starling, R. L. C.; Evans, P. A. +1 more
The second Swift-XRT Point Source catalogue offers a combination of sky coverage and sensitivity and presents an invaluable opportunity for transient discovery. We search the catalogue at the positions of inactive and active galaxies, and identify transient candidates by comparison with XMM-Newton and ROSAT. We recover 167 previously known transie…
The impact of photospheric brightness field on exoplanetary transit timings and the TTV excess of HD 189733 b
Baluev, Roman V.
We consider the issue of excessive TTV noise observed for the exoplanet HD 189733 b. Trying to explain it through the host star photospheric activity, we model the stellar surface brightness as a random field, then characterize statistical properties of the resulting transit signal perturbation and compute individual corrections to transit timings…
Far-ultraviolet investigation into the galactic globular cluster M30 (NGC 7099) - II. Potential X-ray counterparts and variable sources
Zurek, David R.; Kroupa, Pavel; Long, Knox S. +4 more
We present a far-ultraviolet (FUV) study of the globular cluster M30 (NGC 7099). The images were obtained using the Advanced Camera for Surveys (ACS/SBC, F150LP, FUV) and the Wide Field Planetary Camera 2 (WFPC2; F300W, UV) on board the Hubble Space Telescope (HST). We compare the catalogue of FUV objects to 10 known X-ray sources and find six con…
Searching for shell stars in LAMOST DR4 by probing the Fe 42 multiplet lines
Paunzen, Ernst; Hümmerich, Stefan; Bernhard, Klaus
Shell stars, in particular the cooler ones, often do not show conspicuous Balmer-line emission and may consequently be missed in surveys that specifically search for emission signatures in the H α line. This work is aimed at identifying stars with shell-signatures via a search for strong Fe II multiplet 42 lines at λλ4924, 5018, 5169 Å in archival…
Supernova remnant W51C: optical and X-ray emission analysis
Rosado, M.; Arias, L.; Reyes-Iturbide, J. +4 more
We present observations of the optical and X-ray emission from the Galactic supernova remnant W51C. From [S II] Fabry-Pérot interferometry and H α and [S II] images we detect filaments that are part of the optical counterpart of the supernova remnant. We obtain the kinematic distance to W51C, showing that it is one of the shortest distances report…
Jet from the enigmatic high-latitude star BP Psc and evolutionary status of its driving source
Shakhovskoy, D. N.; Potravnov, Ilya S.; Khovritchev, M. Yu +1 more
BP Psc is an active late-type (sp:G9) star with unclear evolutionary status lying at high-galactic latitude b = -57°. It is also the source of the well collimated bipolar jet. We present results of the proper motion and radial velocity study of BP Psc outflow based on the archival Hα imaging with the GMOS camera at 8.1-m Gemini-North telescope as …
Two newly identified eclipsing binaries in open cluster NGC 3532
Özdarcan, O.
We present light-curve analyses of two newly identified detached eclipsing binaries, namely HD 96609 and HD 303734, in the region of the richly populated open cluster NGC 3532. HD 96609 is composed of two main sequence stars (B9-A0V + A2V) with masses and radii of M1 = 2.66 ± 0.02 M⊙, M2 = 1.84 ± 0.01 M⊙…
Adjusting the bow-tie: a morpho-kinematic study of NGC 40
López, J. A.; Estrada-Dorado, S.; Guerrero, M. A. +4 more
We present a comprehensive study of the ionization structure and kinematics of the planetary nebula (PN) NGC 40 (a.k.a. the Bow-tie Nebula). A set of narrow-band images obtained with the Alhambra Faint Object Spectrograph and Camera at the Nordic Optical Telescope are used to study the turbulent distribution of gas in the main cavity, the ionizati…