Related papers: Carbon Star CGCS 673 identified as a Semi-regular …
We have conducted a spectral line survey in the 332 - 364 GHz region with the ASTE 10 m telescope toward R CrA IRS7B, a low-mass protostar in the Class 0 or Class 0/I transitional stage. We have also performed some supplementary…
We present HST/STIS (1160--1700A) echelle spectra of the cataclysmic variable (CV) star, QU Car, observed in time-tag mode at three epochs. In catalogues this binary is classified as a nova-like variable. We find evidence of a high-state…
Using a radiative transfer code (DUSTY) parameters of the circumstellar dust shells of 15 hot post-AGB stars have been derived. Combining the optical, near and far-infrared (ISO, IRAS) data of the stars, we have reconstructed their spectral…
We analyse spectroscopic observations of the B[e] star HD 50138 (MWC 158, V743 Mon, or IRAS 06491-0654), a member of the FS CMa group, obtained over the last twenty years. Four different epochs are identified in the observational data,…
gamma Draconis, a K5III star, showed radial velocity (RV) variations consistent with a 10.7 Jupiter mass planet from 2003-2011. After 2011, the periodic signal decayed, then reappeared with a phase shift. Hatzes et al. (2018) suggested that…
Context. Observations of cataclysmic variables in globular clusters appear to show a dearth of outbursts compared to those observed in the field. A number of explanations have been proposed, including low mass-transfer rates and/or moderate…
We present new Spitzer/IRAC observations of 55 dusty Long Period Variables (LPVs, 48 AGB and 6 RSG stars) in the Galaxy that have different chemistry, variability type, and mass-loss rate. O-rich AGB stars (including intrinsic S-type) tend…
We present modeling of the long-term optical light curve and radial velocity curve of the binary stellar system CXOGBS J175553.2-281633, first detected in X-rays in the \textit{Chandra} Galactic Bulge Survey. We analyzed 7 years of optical…
We report the discovery and characterization of a new cataclysmic variable (CV), 2CXO J050740.7-091337 (hereafter 2CXO J0507), identified using the X-ray main sequence through a cross-match between the Chandra Source Catalogue 2.1 and Gaia…
We report spectroscopic observations of seven bright southern cataclysmic variable stars, collected on a single two-week observing run using the 1.9-m Radcliffe telescope at the South African Astronomical Observatory. We used radial…
We have analysed the photometric data obtained with the STEREO spacecraft for 558 non-magnetic chemically peculiar (CP) stars to search for rotational and pulsational variability. Applying the Lomb-Scargle and the phase dispersion…
This work is a continuation of the studies of the ultrafast variability of line profiles in the spectra of early-type stars. Line profile variations (LPVs) in the spectrum a chemically peculiar A0Vp star $\alpha^2\,$CVn are investigated…
We report the discovery of a new 13th magnitude variable in Cassiopeia close to the variable KP Cas. Analysis of 6 days of intensive photometry shows a regular, near sinusoidal modulation with an amplitude of 0.024 magnitudes and a period…
FF Cam is a variable star near the North celestial pole with hydrogen lines in emission. Its optical variability of ~0.3 mag was discovered by HIPPARCOS. The spectral type assigned to the star in SIMBAD is B9, but its position coincides…
A periodogram analysis of 47 stars noted in GCVS as RV-type stars was carried out. The research methods applied here to RV-type stars have previously been applied to long-period variables Mira-type stars and semi-variables. Periodograms are…
We present CCD photometric observations of the slow irregular type variable KU Her. We have also used observations from the ASAS Database and the AAVSO International Database. The V-band observations span eight years from August of 2002 to…
As a byproduct of our search for Galactic stellar systems with gamma-ray emission, we have identified an unrelated cool and evolved star (IRC-10412) that attracted our attention due to its strong radio emission level with a spectral index…
Dwarf carbon (dC) stars, main sequence stars showing carbon molecular bands, are enriched by mass transfer from a previous asymptotic-giant-branch (AGB) companion, which has since evolved to a white dwarf. While previous studies have found…
Images recorded with the Gemini Multi-Object Spectrograph (GMOS) on Gemini South are combined with archival images from other facilities to search for variable stars in the southern portion of the nearby disk galaxy NGC 247. Fifteen new…
Stars with unusual properties can provide a wealth of information about rare stages of stellar evolution and exotic physics. However, determining the true nature of peculiar stars is often difficult. In this work, we conduct a systematic…