Search Publications
KM UMa: An Active Short-period Detached Eclipsing Binary in a Hierarchical Quadruple System
Meng, Fangbin; Zhu, Liying; Liu, Nianping +4 more
The first detailed photometric and spectroscopic analysis of the G-type eclipsing binary KM UMa is presented, which indicates that the system is a short-period detached eclipsing binary. The radial velocity curves were calculated using the cross-correlation function method based on Large Sky Area Multi-Object Fiber Spectroscopic Telescope, Sloan D…
Variability of the Ultraluminous X-ray Source M 74 X-1 in X-ray and Optical Ranges
Atapin, K. E.; Vinokurov, A. S.; Solovyeva, Yu. N. +1 more
Using observations of M 74 X-1 obtained with the Chandra X-ray Observatory and the Hubble Space Telescope, we identified this source in the optical range. Analysis of other archival data allowed us to track the evolution of M 74 X-1 over two decades of observations, as well as to search for a correlation between the object's variability in the X-r…
Detection of Two Totally Eclipsing B-type Binaries with Extremely Low Mass Ratios
Qian, Shengbang; Li, Fuxing; Zang, Lei +1 more
The detection of O- and B-type stars with extremely low-mass companions is very important for understanding the formation and evolution of binary stars. However, finding them remains a challenge because the low-mass components in such systems contribute such small flux to the total. During our search for pulsations among O- and B-type stars using …
The Digitized First Byurakan Survey Database Late-Type Stars Candidates. New Confirmations. II
Gigoyan, K. K.; Gigoyan, K. S.; Kostandyan, G. R. +5 more
Three new carbon C stars was confirmed among the sample of the Late-Type Stars candidates, selected on the Digitized First Byurakan Survey (DFBS) spectral plates. The DFBS is the digitized version of the First Byurakan Survey (FBS, or Markarian survey). The FBS was the first systematic survey of the extragalactic sky. This objective-prism survey w…
The GAPS Programme at TNG: LVIII. Two multi-planet systems with long-period substellar companions around metal-rich stars
Scandariato, G.; Marzari, F.; Sozzetti, A. +20 more
Context. Due to observational biases, a large fraction of known exoplanets are short-period objects. However, the search for planets began more than 20 yr ago, and so it is already possible – with the use of a suitable dataset – to begin exploring a wider range of the parameter space, such as that encompassing long-period planets. Aims. The aim of…
First deep X-ray observations of the Fermi-detected steep-spectrum source and radio-loud NLS1 galaxy 3C 286
Komossa, S.; Grupe, D.; Kraus, A. +1 more
A well-known calibrator source in radio astronomy, 3C 286 ($z=0.85$), is a compact steep-spectrum (CSS) radio source and spectroscopically classified as a narrow-line Seyfert 1 (NLS1) galaxy. It is also known for its damped Ly $\alpha$ system from an intervening galaxy at $z=0.692$ detected in both ultraviolet (UV) and radio spectra. In addition, …
X Persei: A study on the origin of its high-energy emission
Fiocchi, M.; Natalucci, L.; Rodi, J.
Aims. The origin of the hard X-ray emission in the Be/X-ray binary system X Persei has long been debated as its atypical 'two-hump' spectrum can be modelled in multiple ways. The main debate focuses on the the high-energy hump, which is fit as either a cyclotron resonance scatter frequency (CRSF) or inverse Comptonization due to bulk Comptonizatio…
High-resolution Observations of Clustered Dynamic Extreme-Ultraviolet Bright Tadpoles Near the Footpoints of Corona Loops
Chitta, L. P.; Wang, Rui; Liu, Ying D. +2 more
An extreme ultraviolet (EUV) close-up view of the Sun offers unprecedented detail of heating events in the solar corona. Enhanced temporal and spatial images obtained by the Solar Orbiter during its first science perihelion enabled us to identify clustered EUV bright tadpoles (CEBTs) occurring near the footpoints of coronal loops. Combining SDO/AI…
Probing the Galactic Halo with RR Lyrae Stars. VI. The Radial Velocity Curve Templates of RRc Stars
Fang, Min; Tian, Haijun; Shi, Jianrong +8 more
We present radial velocity (RV) curve templates of RR Lyrae first-overtone (RRc) stars constructed with the Mg I b triplet and Hα lines using time-domain Medium-Resolution Survey spectra of seven RRc stars from Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) Data Release 9. Additionally, we derive the relation between the stella…
Comment on Ádám et al. (2023): Large fraction of already known systems reported
Zasche, P.
In this work, I report that large fraction of stars detected by Ádám et al. (2023, A&A, 674, A170) and noted in that work as new discoveries are in fact known systems. This is especially true for the dense bulge fields with large blending of nearby sources. Among the published 245 stars determined to be doubly eclipsing (i.e. containing two ec…