相关论文: MP Gem: VY Scl-type star, finally

We call attention to the fact that one of the brightest red supergiants in the SMC has recently changed its spectral type from K0-1 I (December 2004) to M4 I (December 2005) and back to K0-1 I (September 2006). An archival spectrum from the…

This study aims at timing the eclipses of the binary star TU UMi. The times of minima are taken from the literature, from our observations in April 2004 and from TESS observations between 2019 and 2022. The orbital period analysis of the…

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…

The new discovered short-period close binary star, XY LMi, was monitored photometrically since 2006. It is shown that the light curves are typical EW-type and show complete eclipses with an eclipse duration of about 80 minutes. By analyzing…

Studies during the last decade have revealed that nearly all Globular Clusters (GCs) host multiple populations (MPs) of stars with a distinctive chemical patterns in light elements. No evidence of such MPs has been found so far in…

Complex periodic variables (CPVs) are stars that exhibit highly structured and periodic optical light curves. Previous studies have indicated that these stars are typically disk-free pre-main-sequence M dwarfs with rotation periods ranging…

WY Cancri is a short-period ($P$=0.829 d) eclipsing RS Canum Venaticorum stars, and both components are late-type stars. Recently, observations provided by photometric observations and light time minima show that the orbital period of WY…

On May 5 2022, a type Ic supernova (SN) explosion SN~2022jli was discovered. This SN showed additional optical emissions, which were found to exhibit 12.4-day periodic undulations and concordant periodic velocity shifts. These key features…

Pulsational properties of 1.8 M$_{\odot}$ stellar models covering the latest stages of contraction toward the main sequence up to early hydrogen burning phases are investigated by means of linear nonadiabatic analyses. Results confirm that…

Chemically peculiar (CP) stars are main-sequence A and B stars with abnormally strong or weak lines for certain elements. They generally have magnetic fields and all observables tend to vary with the same period. Chemically peculiar stars…

The discovery of star-to-star abundance variations (a.k.a. multiple populations - MPs) within globular clusters (GCs), which are generally not found in the field or in lower mass open clusters, has led to a search for the unique property of…

We present new spectroscopic observations of the detached late-type double-lined eclipsing binary YY Gem, a member of the Castor sextuple system and one of the benchmarks for the comparison between observations and stellar evolution theory…

We present the results of a time-resolved photometric and time-series analysis of a RR Lyrae type star RR Gem. The main results are as follows: We found RR Gem's pulsation period, 0.39689 d, and its V and I mean magnitudes, 11.277 (V) and…

We studied the IW And star V507 Cyg using ASAS-SN data, ZTF data and our snapshot photometry. The star has been found to be in a long standstill in 2020 May-2022 March (and it still continues now). Such long-lasting standstills have been…

FS CMa type stars is a group of ~70 objects formerly known as unclassified stars with the B[e] phenomenon. Their very strong emission-line spectra in combination with a nearly main-sequence luminosity suggest the binary nature for them.…

We present the properties of the recently discovered class of variable stars, Blue Large-Amplitude Pulsators (BLAPs). These extremely rare, short-period pulsating objects were detected thanks to regular, high-cadence observations of…

We present a study of the cataclysmic variable star PT Per based on archival XMM-Newton X-ray data and new optical spectroscopy from the WHT with ISIS. The X-ray data show deep minima which recur at a period of 82 minutes and a hard,…

The quest for quiet or dormant black holes has been ongoing since several decades. Ellipsoidal variables possibly indicate the existence of a very high-mass invisible companion and are thought to be one of the best ways to find such dormant…

We report the serendipituous discovery of the new eclipsing polar 2XMMp J131223.4+173659. Its striking X-ray light curve attracted immediate interest when we were visually inspecting the source products of the 2XMMp catalogue. This light…

The tenth part of the OGLE-III Catalog of Variable Stars contains 125 Double Periodic Variables (DPVs) from the Large Magellanic Cloud. DPVs are semi-detached binaries which show additional variability with a period around 33 times longer…