Related papers: Variability in a Young, L/T Transition Planetary-M…

HS 2325+8205 is a long-period eclipsing dwarf nova with an orbital period above the period gap (Porb>3 h) and is reported to be a Z Cam-type dwarf nova. Based on the photometry of the Transiting Exoplanet Survey Satellite (TESS), the light…

We present the results of an aperture masking interferometry survey for substellar companions around 67 members of the young (~8-200Myr) nearby (~5-86pc) AB Doradus, Beta Pictoris, Hercules-Lyra, TW Hya, and Tucana-Horologium stellar…

Aims: We aim to study the near-infrared variability of the T8 dwarfs 2MASS J09393548-2448279 and EQ J1959-3338 by analyzing their $J$-band photometric signal, which can provide new insights into the atmospheric dynamics of cold brown…

PSR J1518+4904 is a recently discovered 40.9~ms pulsar in an 8.6 day, moderately eccentric orbit. We have measured pulse arrival times for this pulsar over 1.4~yr at several radio frequencies, from which we have derived high precision…

We present spectral and kinematic evidence that 2MASS J06085283-2753583 (M8.5gamma) is a member of the beta Pictoris Moving Group (BPMG, age ~12 Myr), making it the latest-type known member of this young, nearby association. We confirm…

We report on optical observations of the low-mass binary millisecond pulsar systems J0034-0534 and J2145-0750. A faint (I=23.5) object was found to be coincident with the timing position of PSR J2145-0750. While a galaxy or distant…

The 1RXS J034231.8+121622 system consists of an M dwarf primary and a directly imaged low-mass stellar companion. We use high resolution spectroscopic data from Keck/KPIC to estimate the objects' atmospheric parameters and radial velocities…

To understand how planetary spin evolves and traces planet formation processes, we measure rotational line broadening in eight planetary-mass objects (PMOs) of various ages (1--800 Myr) using near-infrared high-resolution spectra from…

We report on the results of a spectroscopic and photometric study of a new cataclysmic variable, identified as optical counterpart of the X-ray source RX J1554.2+2721 detected by ROSAT. The spectroscopic observations of the relatively…

We present the discovery of 2MASS J11263991-5003550 identified as part of an ongoing survey to discover ultra-cool dwarfs in the Southern Galactic Plane, using data from the 2MASS and SuperCOSMOS Sky Surveys. Strong FeH and H2O absorption…

Mid-infrared (mid-IR) variability in young stellar objects (YSOs) is driven by several physical mechanisms, which produce a variety of amplitudes and light curve shapes. One of these mechanisms, variable disk accretion is predicted by…

We present medium-resolution VLT/FORS2 spectroscopy of six cataclysmic variables discovered by the Sloan Digital Sky Survey. We determine orbital periods for SDSS J023322.61+005059.5 (96.08 +/- 0.09 min), SDSS J091127.36+084140.7 (295.74…

We present a new epoch of JWST spectroscopic variability monitoring of the benchmark binary brown dwarf WISE 1049AB, the closest, brightest brown dwarfs known. Our 8-hour MIRI low resolution spectroscopy (LRS) and 7-hour NIRSpec prism…

We present results of 6 years of observations, reduced and analyzed with the same tools in a systematic way. We report completely new data for 15 objects, for 5 objects we present a new analysis of previously published results plus…

We have obtained high contrast images of four nearby, faint, and very low mass objects 2MASSJ04351455-1414468, SDSSJ044337.61+000205.1, 2MASSJ06085283-2753583 and 2MASSJ06524851-5741376 (here after 2MASS0435-14, SDSS0443+00, 2MASS0608-27…

We conducted a comprehensive analysis of young stellar object (YSO) variability at submillimeter and mid-infrared (mid-IR) wavelengths for the M\,17 \ion{H}{2} region, using 3.5 years monitoring data from the JCMT Transient Survey at $450$…

FU Orionis objects (FUors) are rapidly-accreting, pre-main sequence objects that are known to exhibit large outbursts at optical and near-infrared wavelengths, with post-eruption, small-scale photometric variability superimposed on…

We study the variability of the cataclysmic variable DO Dra, on time-scales of between minutes and decades. The characteristic decay time dt/dm=0.902(3) days/mag was estimated from our 3 nights of CCD R observations. The quiescent data show…

We present a multi-year survey aimed at collecting (1) high-precision (~5 milli-mag), (2) fast-cadence (~3 min), and (3) relatively long duration (~10 days) multi-band photometric series. The goal of the survey is to discover and…

Determination of stellar age is a crucial task in astrophysics research. Different methods are nowadays used either model dependent or based on calibrated empirical relations. The most reliable results are generally obtained when different…